BACKGROUND OF THE INVENTION
1. Technical Field
[0001] Embodiment of the invention generally relates to a method of automatically balancing
ionized air stream created in bipolar corona discharge as defined in claim 1, and
to an apparatus for an automatically balanced ionizing blower as defined in claim
5.
2. Background Art
[0003] Static charge neutralizers are designed to remove or minimize static charge accumulation.
Static charge neutralizers remove static charge by generating air ions and delivering
those ions to a charged target.
[0004] One specific category of static charge neutralizers is the ionizing blower. An ionizing
blower normally generates air ions with a corona electrode, and uses a fan (or fans)
to direct air ions toward the target of interest.
[0005] Monitoring or controlling the performance of a blower utilizes two measurements.
[0006] The first measurement is balance. Ideal balance occurs when the number of positive
air ions equals the number of negative air ions. On a charge plate monitor, the ideal
reading is zero. In practice, the static neutralizer is controlled within a small
range around zero. For example, a static neutralizer's balance might be specified
as approximately ±0.2 volts.
[0007] The second measurement is air ion current. Higher air ion currents are useful because
static charges can be discharged in a shorter time period. Higher air ion currents
correlate with low discharge times that are measured with a charge plate monitor.
BRIEF SUMMARY
[0008] In the invention, a method of automatically balancing ionized air stream created
in bipolar corona discharge is provided as defined in claim 1.
[0009] In another aspect of the invention, an apparatus for an automatically balanced ionizing
blower is provided as defined in claim 6.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Various embodiments of this disclosure that are proposed as examples will be described
in detail with reference to the following figures, wherein like numerals reference
like elements, and wherein:
Figure 1A is a block diagram of a general view of an ionizing blower, in accordance
with an embodiment of the invention.
Figure 1B is a cross sectional view of the blower of Figure 1A.
Figure 1C is a block diagram of a sensor included in an ionizing blower, in accordance
with an embodiment of the invention.
Figure 2A is a block diagram of the ionizing blower of Figure 1A and the ionized air
stream from the blower, in accordance with an embodiment of the invention.
Figure 2B is an electrical block diagram of a system in the ionizing blower, in accordance
with an embodiment of the invention.
Figure 3 is a flowchart of a feedback algorithm 300, in accordance with an embodiment
of the invention.
Figure 4 is a flowchart of a micropulse generator algorithm of a micropulse generator
control, in accordance with an embodiment of the invention.
Figure 5A is a flowchart of a system operation during the formation of a negative
pulse train, in accordance with an embodiment of the invention.
Figure 5B is a flowchart of a system operation during the formation of a positive
pulse train, in accordance with an embodiment of the invention.
Figure 6 is a flowchart of a system operation during a present pulse phase, in accordance
with an embodiment of the invention.
Figure 7 is a flowchart of a system operation during the sensor input measurement,
in accordance with an embodiment of the invention.
Figure 8 are waveform diagrams of micropulses, in accordance with an embodiment of
the invention.
Figure 9 is a flowchart of a system operation during a balance alarm, in accordance
with an embodiment of the invention.
DETAILED DESCRIPTION
[0011] In the following detailed description, for purposes of explanation, numerous specific
details are set forth to provide a thorough understanding of the various embodiments
of the present invention. Those of ordinary skill in the art will realize that these
various embodiments of the present invention are illustrative only and are not intended
to be limiting in any way.
[0012] An embodiment of the present invention can apply to many types of air-gas ionizers
configured as, for example, ionizing bars, blowers, or in-line ionization devices.
[0013] Wide area coverage ionizing blowers requires combination of highly efficient air
ionization with short discharge time and tight ion balance control. Figure 1A is a
block diagram of a general view of an ionizing blower 100, in accordance with an embodiment
of the invention, while Figure 1B is a cross sectional view of the blower 100 of Figure
1A along the line A-A. The efficient air ionization is achieved by the bipolar corona
discharge created between the array of emitter points 102 (i.e., emitter points array
102) and two reference electrodes 104,105 (shown as upper reference electrode 104
and lower reference electrode 105). The emitter points 102 mounted on a protective
grill 106 (i.e., air duct 106) which also helps equally to speed an ionized air flow.
[0014] A fan 103 (Figure 1A) is an air moving device that provides a high variable air flow
125 in a space 130 between the emitter points array 102 (ion emitter(s) 102) and the
two reference electrodes 104,105. The air duct 106 concentrates and distributes air
flow 125 in the space 130 of a corona discharge. Corona generated positive and negative
ions are moving between electrodes 102, 104 and 105. The air flow 125 is able to take
and carry only a relatively small portion of positive and negative ions created by
the corona discharge.
[0015] According to one embodiment of the invention, the air 125 is forced out of the air
duct (106) outlet 131 and the air 125 passes an air ionization voltage sensor 101.
Details one embodiment of a design of the air ionization voltage sensor 101 are shown
in Figure 1C. A fan (shown as block 126 in Figure 1B) provides the flow of air 125.
The air ionization voltage sensor 101 has a louver type thin dielectric plate 109
stretched on full width of the duct 106. The louver plate 109 directs a portion 125a
(or sample 125a) of the ionized air flow 125b (ionized air stream 125b) coming from
the duct 106 and upper electrode 104 (see also Figure 2A), so that the air ionization
voltage sensor 101 can sense and collect some of the ion charges in the portion 125a
of the ionized air flow 125b. The collected ion charges then creates the control Signal
250 (Figure 2) for use by the algorithm 300 (Figure 3) for balancing the ions in the
ionizing blower 100. A top side 132 of the plate 109 has a narrow metal strip functioning
as a sensitive electrode 108 and a bottom side 133 has wider grounded plain electrode
110. This electrode 110 is typically shielded so that the air ionization voltage sensor
101 is shielded from the high electrical field of the emitter points array 102. The
electrode 108 collects some of the ion's charges resulting in a voltage/signal 135
(Figure 2A) that is proportional to ion balance in the ionized air flow 125b. The
voltage/signal 135 from the air ionization voltage sensor 101 used by the control
system 107 (shown in Figure 2 as system 200) to monitor and adjust the ion balance
in the ionized air flow 125b. This signal 135 is also represented by the signal 250
which is input into the sample and hold circuit 205 as will be discussed further below.
Other configurations of ion balance sensors, for example, in the form of conductive
grille or metal mesh immersed in the ion flow also can be used in other embodiments
of the invention.
[0016] According to another embodiment of the invention, an ionization return current sensor
204 is used to monitor ionized flow balance. Therefore, one embodiment of the invention
provides a system 200 (Figure 2) comprising the ionization return current sensor 204
for monitoring the ionized air flow balance. In another embodiment of the invention,
the system 200 comprises the air ionization voltage sensor 101 for monitoring the
ionized air flow balance.
[0017] In yet another embodiment of the invention, the system 200 comprises the dual sensors
comprising the air ionization voltage sensor 101 and ionization return current sensor
204, with both sensors 101 and 204 configured for monitoring the ionized air flow
balance.
[0018] The ionization return current sensor 204 includes the capacitor C2 and capacitor
C1, and resistors R1 and R2. The capacitor C2 provides an AC current path to ground,
bypassing the current detect circuit. The resistor R2 converts the Ion current to
a voltage (Ii*R2), and the resistors R1 and R2 and capacitor C2 form a low pass filter
to filter out induced currents created by the micro pulse. The return current 210
flowing from the ionization return current sensor 204 is shown as 12.
[0019] The current 254 flowing to the emitter points 102 is the current summation Z(Ii(+),Ii(-),I2,Ic1,Ic2)
where the currents Ic1 and Ic2 are the currents flowing through the capacitors C1
and C2, respectively.
[0020] Figure 2A illustrates ion currents 220 flowing between the emitters 102 and reference
electrodes 104, 105. The air flow 125 from the duct 106 converts a portion of these
two ion currents 220 in an ionized air flow 125b which is moving to a target of charge
neutralization outside the blower 100. The target is generally shown in Figure 1B
as the block 127 which can be placed in different locations with respect to the ionizing
blower 100.
[0021] Figure 2B shows an electrical block diagram of a system 200 in the ionizing blower
100, in accordance with an embodiment of the invention. The system 200 includes an
ionization return current sensor 204, micro-pulse high voltage power supply 230 (micro-pulsed
AC power source 230) (which is formed by the pulse driver 202 and high voltage (HV)
transformer 203), and a control system 201 of the Ionizing blower. In an embodiment,
the control system 201 is a microcontroller 201. The microcontroller 201 receives
a power from a voltage bias 256 which may be at, for example, about 3.3 DC voltage
and is grounded at line 257.
[0022] A power converter 209 may be optionally used in the system 200 to provide various
voltages (e.g. -12 VDC, 12VDC, or 3.3VDC) that is used by the system 200. The power
converter 209 may convert a voltage source value 258 (e.g., 24 VDC) into various voltages
256 for biasing the microcontroller 201.
[0023] The micro-pulse high voltage power supply 230 has a pulse driver 202 controlled by
Micro-Controller 201. The pulse driver 202 is connected to a step up pulse transformer
203. The transformer 203 generates short duration pulses (in microsecond range) positive
and negative polarities having amplitudes sufficient to produce corona discharge.
The secondary coil of the transformer 203 is floated relatively to ground. A high
voltage terminal 250 of transformer 203 is connected to the emitter points array 102
and a low voltage terminal 251 of transformer 203 is connected to the reference electrodes
104, 105.
[0024] The short duration high voltage AC pulses (generated by the high voltage power supply
230) result in significant capacitive or displacement currents
Ic1 and
Ic2 flowing between electrodes 102 and 104,105. For example, the current Ic1 flows between
the electrodes (emitter points) 102 and the upper reference electrode 104, and the
current Ic2 flows between the electrodes 102 and the lower reference electrode 105.
Relatively small positive and negative ion corona currents marked as
Ii(+) and
Ii(-) leave this ions generation system 200 into the environment outside blower 100 and
moving to the target.
[0025] To separate the capacitive and ion currents, the ion generating system 200 is arranged
in a closed loop circuit for high frequency AC capacitive currents marked
Ic1 and
Ic2 as the secondary coil of transformer 203 and corona electrodes 102,104 and 105 are
virtually floated relative to ground and the ion currents
Ii(+) and Ii(-) have a return path (and transmits) to ground. AC currents have significantly lower
resistance to circulate inside this loop than these AC currents transmitting to ground.
[0026] The system 200 includes the ion balance monitor providing separation ions convection
currents from pulsed AC currents by arranging closed loop current path between the
pulsed AC voltage source 230, said ion emitter 102 and reference electrode 104 or
105.
[0027] Additionally, ion balance monitoring is performed in the system 200 during time periods
between the micro-pulses. Additionally, ion balance monitoring is performed by integrating
differential signals of the positive and negative convection currents.
[0028] The transformer 203 of the high voltage source 230, the ion emitter 102 and reference
electrode 104 or 105 are arranged in a closed loop for AC current circuit and the
closed loop is connected to ground by a high value viewing resistor
R2.
[0029] The law of charge conservation dictates that as the output (via transformer 203)
of AC voltage source 230 is floated, the ion current is equal to a sum of positive
Ii(+) and negative
Ii(-) ion currents. These currents
Ii(+) and
Ii(-) have to return through the circuitry of the ionization return current sensor 204
in the system 200. The amount of each polarity ion current are:
Ii(+)=Q(+)*N(+)*U
and
Ii(-)=Q(-)*N(-).*U
[0030] Where
Q is charge of positive or negative ion,
N is ion concentration, and
U is air flow. An ion balance will be achieved if absolute values of positive
Ii(+) and negative
Ii(-) currents are the same. It is known in the art that both polarities of air ions carry
about the same amount of charge (equal to one electron). So, another condition of
ion balance is equal concentrations of both polarity ions. The air ionization voltage
sensor 101 (ion balance monitor) is more sensitive to variation in the ion concentration,
in contrast to the ionization return current sensor 204 (ion balance monitor) which
is sensitive to ion currents changes. Therefore, the speed of the response of the
air ionization voltage sensor (capacitor sensor) 101 is typically faster than the
response of the ionization return current sensor 204.
[0031] A greater number of positive ions detected by the air ionization voltage sensor 101
results in the air ionization voltage sensor 101 generating a positive output voltage
that is input into (and processed by) the sample and hold circuit 205. A greater number
of negative ions detected by the air ionization voltage sensor 101 results in the
air ionization voltage sensor 101 generating a negative output voltage that is input
into (and processed by) the sample and hold circuit 205. In contrast, as similarly
described above, absolute values of positive Ii(+) and negative Ii(-) are used by
the ionization return current sensor 204 to output the signal 250 for input into the
sample and hold circuit 205 to determine and achieve an ion balance in the ionization
blower 100.
[0032] At the time between a micropulse train, the sample signal 215 will close the switch
216 so that amplifier 218 is connected to the capacitor C3 which is then charged to
a value based in response to the input signal 250.
[0033] The ion currents floated with air stream are characterized by very low frequency
and can be monitored by passing through a high mega ohm resistive circuitry R1 and
R2 to ground. To minimize the influence of capacitive and parasitic high frequency
currents, the ionization return current sensor 204 has two bypass capacitive paths
with C1 and C2.
[0034] The difference in currents
Ii(+) and
Ii(-) are continuously measured by the ionization return current sensor 204. The resulting
current passing though resistive circuitry R1, R2 produces a voltage/signal proportional
to integrated/averaged in time ion balance of the air stream that left the blower.
This resulting current is shown as current 214 which is expressed by the summation
Σ(Ii(+),Ii(-).
[0035] The ion balance monitoring is achieved by measuring voltage output of ionization
return current sensor 204, or by measuring output of the air ionization voltage sensor
101, or by measuring voltage from an air ionization voltage sensor 101 and ionization
return current sensor 204. For purposes of clarity, the voltage outputs of the ionization
return current sensor 204 and voltage output of the air ionization voltage sensor
101 are each shown in Figure 2 by the same signal 250. This signal 250 is applied
to the input of a sample and hold circuit 205 (sampling circuit 205) that is controlled
by the Microcontroller 201 via the sample signal 215 which opens the switch 216 to
trigger a sample and hold operation on the signal 250.
[0036] In some cases or embodiments for corona system, diagnostic signals from both sensors
101 and 204 can be compared. These diagnostic signals are input as signal 250 into
the sample and hold circuit 205.
[0037] The signal 250 is then conditioned by a low pass filter 206 and amplified by the
amplifier 207 before being applied to the input of the Analog to Digital Converter
(ADC) residing inside the Microcontroller 201. The sample and hold circuit 205 samples
the signal 250 between pulses times to minimize noise in the recovered signal 250.
Capacitor C3 holds the last signal value in-between sample times. Amplifier 207 amplifies
the signal 250 to a more usable level for the microcontroller 201, and this amplified
signal from the amplifier 207 is shown as the balance signal 252.
[0038] The microcontroller 201 compares the balance signal 252 with a setpoint signal 253
which is a reference signal generated by the balance adjustment potentiometer 208.
The setpoint signal 253 is a variable signal that can be adjusted by the potentiometer
208.
[0039] The setpoint signal 253 can be adjusted in order to compensate for different environments
of the ionizing blower 100. For example, the reference level (ground) near the output
131 (Figure 1B) of the ionizing blower 100 may be approximately zero, while the reference
level near an ionization target may not be zero. For example, more negative ions might
be lost at the location of the ionization target if the location has a strong ground
potential value. Therefore, the setpoint signal 253 may be adjusted so as to compensate
for the non-zero value of the reference level at a location of the ionization target.
The setpoint signal 253 can be decreased in this case so that the microcontroller
201 can drive the pulse driver 202 to control the HV transformer 230 to generate an
HV output 254 that generates more positive ions at the emitter points 102 (due to
the lower setpoint value 253 used as a comparison for trigger more positive ions generation)
so as to compensate for the loss of negative ions at the location of the ionization
target.
[0040] Reference is now made to Figures 2 and 8. In an embodiment of the invention, the
ionization blower 100 can achieve an ion balance in the ionizing blower 100 based
on at least one or more of the following: (1) by increasing and/or decreasing the
positive pulse width value and/or negative pulse width value, (2) by increasing and/or
decreasing the time between positive pulses and/or time between negative pulses, and/or
(3) by increasing and/or decreasing the number positive pulses and/or negative pulses,
as described below. The microcontroller 201 outputs the positive pulse output 815
and negative pulse output 816 (Figures 2 and 8) which are driven into and controls
the pulse driver 202. In response to the outputs 815 and 816, the transformer 230
generates the ionization waveform 814 (HV output 814) that is applied to the emitter
points 102 so as to generate an amount of positive ions and an amount of negative
ions based on the ionization waveform 814.
[0041] As an example, if the air ionization voltage sensor 101 and/or the ionization return
current sensor 204 detects an ion imbalance in the ionizing blower 100 where the amount
positive ions exceeds the amount of negative ions in the blower 100, the balance signal
252 into the microcontroller 201 will indicate this ion imbalance. The microcontroller
201 will lengthen the negative pulse width (duration) 811 of negative pulses 804.
Since the width 811 is lengthened, the amplitude of the negative micropulses 802 is
increased. The positive micropulses 801 and negative micropulses 802 are high voltages
output that are driven to the emitter points 102. The increased amplitude of the negative
micropulses 802 will increase the negative ions generated from the emitter points
102. The ionization waveform 814 has generated variable polarity groups of short duration
ionizing micro-pulses 801 and 802. The micro-pulses 801 and 802 are predominantly
asymmetric in amplitude and duration of both polarity voltages and have a magnitude
of at least one polarity ionizing pulses exceed the corona threshold.
[0042] Once the maximum pulse width has been reached for the negative pulse width 811, if
the amount of positive ions is still exceeding the amount of negative ions in the
blower 100, then the microcontroller 201 will shorten the positive pulse width (duration)
810 of positive pulses 803. Since the width 810 is shortened, the amplitude of the
positive micropulses 801 is decreased. The decreased amplitude of the positive micropulses
801 will decrease the positive ions generated from the emitter points 102.
[0043] Alternatively or additionally, if the amount of positive ions exceeds the amount
of negative ions in the blower 100, the microcontroller 201 will lengthen the time
between negative pulses 804 by lengthening the negative Rep-Rate 813 (time interval
between negative pulses 804). Since the negative Rep-Rate 813 is lengthened, the time
between negative micropulses 802 is also increased. As a result, the lengthened or
longer negative Rep-Rate 813 will increase the time between the negative micropulses
802 which will, in turn, increase the amount of time negative ions are generated from
the emitter points 102.
[0044] Once the minimum negative Rep-Rate has been reached for the negative Rep-Rate, if
the amount of positive ions is still exceeding the amount of negative ions in the
blower 100, then the microcontroller 201 will shorten the time between positive pulses
803 by shortening the positive Rep-Rate 812 (time interval between positive pulses
803). Since the positive Rep-Rate 812 is shortened, the time between positive micropulses
801 is also decreased. As a result, the shortened or shorter positive Rep-Rate 811
will decrease the time between the positive micropulses 803 which will, in turn, decrease
the amount of time positive ions generated from the emitter points 102.
[0045] Alternatively or additionally, if the amount of positive ions exceeds the amount
of negative ions in the blower 100, the microcontroller 201 will increase the number
of negative pulses 804 in the negative pulse output 816. The microcontroller 201 has
a negative pulse counter that can be increased so as to increase the number of negative
pulses 804 in the negative pulse output 816. Since the number of negative pulses 804
is increased, the negative pulse train is increased in the negative pulse output 816,
and this increases the number of negative micropulses 802 in the HV output which is
the ionization waveform 814 that is applied to the emitter points 102.
[0046] Once the maximum amount of negative pulses has been added to the negative pulse output
816, if the amount of positive ions is still exceeding the amount of negative ions
in the blower 100, then the microcontroller 201 will decrease the number of positive
pulses 803 in the positive pulse output 815. The microcontroller 201 has a positive
pulse counter that can be decreased so as to decrease the number of positive pulses
803 in the positive pulse output 815. Since the number of positive pulses 803 is decreased,
the positive pulse train in the positive pulse output 815 is decreased and this decreases
the number of positive micropulses 801 in the HV output which is the ionization waveform
814 that is applied to the emitter points 102.
[0047] The following example is directed to achieving an ion balance in the blower 100 when
the amount of negative ions exceeds the amount of positive ions in the blower.
[0048] If the air ionization voltage sensor 101 and/or the ionization return current sensor
204 detects an ion imbalance in the ionizing blower 100 where the amount negative
ions exceed the amount of positive ions in the blower100, the balance signal 252 into
the microcontroller 201 will indicate this ion imbalance. The microcontroller 201
will lengthen the positive pulse width 812 of positive pulses 803. Since the width
810 is lengthened, the amplitude of the positive micropulses 801 is increased. The
increased amplitude of the positive micropulses 801 will increase the positive ions
generated from the emitter points 102.
[0049] Once the maximum pulse width has been reached for the positive pulse width 812, if
the amount of negative ions is still exceeding the amount of positive ions in the
blower 100, then the microcontroller 201 will shorten the negative pulse width 811
of negative pulses 804. Since the width 811 is shortened, the amplitude of the negative
micropulses 802 is decreased. The decreased amplitude of the negative micropulses
802 will decrease the negative ions generated from the emitter points 102.
[0050] Alternatively or additionally, if the amount of negative ions exceeds the amount
of positive ions in the blower 100, the microcontroller 201 will lengthen the time
between positive pulses 803 by lengthening the positive Rep-Rate 812. Since the positive
Rep-Rate 812 is lengthened, the time between positive micropulses 801 is also increased.
As a result, the lengthened or longer positive Rep-Rate 812 will increase the time
between the positive micropulses 801 which will, in turn, increase the amount of time
the positive ions generated from the emitter points 102.
[0051] Once the minimum positive Rep-Rate has been reached for the positive Rep-Rate 812,
if the amount of negative ions are still exceeding the amount of positive ions in
the blower 100, then the microcontroller 201 will lengthen the time between negative
pulses 804 by lengthening the negative Rep-Rate 813. Since the negative Rep-Rate 813
is lengthened, the time between negative micropulses 802 is also increased. As a result,
the lengthened or longer negative Rep-Rate 813 will increase the time between the
negative micropulses 802 which will, in turn, decrease the amount of time the negative
ions generated from the emitter points 102.
[0052] Alternatively or additionally, if the amount of negative ions exceeds the amount
of positive ions in the blower 100, the microcontroller 201 will increase the number
of positive pulses 803 in the positive pulse output 815. The microcontroller 201 has
a positive pulse counter that can be increased so as to increase the number of positive
pulses 803 in the positive pulse output 815. Since the number of positive pulses 803
is increased, the positive pulse train in the positive pulse output 815 is lengthened
and the number of positive micropulses 801 is increased in the HV output which is
the ionization waveform 814 that is applied to the emitter points 102.
[0053] Once the maximum amount of positive pulses has been added to the positive pulse output
815, if the amount of negative ions is still exceeding the amount of positive ions
in the blower 100, then the microcontroller 201 will decrease the number of negative
pulses 804 in the negative pulse output 816. The microcontroller 201 has a negative
pulse counter that can be decreased so as to decrease the number of negative pulses
804 in the negative pulse output 816. Since the number of negative pulses 804 is decreased,
the negative pulse train is shortened in the negative pulse output 816 and the number
of negative micropulses 802 is decreased in the HV output which is the ionization
waveform 814 that is applied to the emitter points 102.
[0054] If the ion imbalance (which is reflected in the balance current value 252) is not
significantly different from the setpoint 253, then a small adjustment in the ion
imbalance may be sufficient and the microcontroller 201 can adjust the pulse widths
811 and/or 810 to achieve ion balance.
[0055] If the ion imbalance (which is reflected in the balance current value 252) is moderately
different from the setpoint 253, then a moderate adjustment in the ion imbalance may
be sufficient and the microcontroller 201 can adjust the Rep-Rates 813 and 812 to
achieve ion balance.
[0056] If the ion imbalance (which is reflected in the balance current value 252) is significantly
different from the setpoint 253, then a large adjustment in the ion imbalance may
be sufficient and the microcontroller 201 can add positive and/or negative pulses
in the outputs 815 and 816, respectively.
[0057] In yet another embodiment of the invention, a duration (pulse width) of at least
one polarity of the micro-pulses in Figure 8 are at least approximately 100 times
shorter than a time interval between micro pulses.
[0058] In yet another embodiment of the invention, the micro-pulses in Figure 8 are arranged
in following one another groups/pulse trains and wherein one polarity pulse train
comprises between approximately 2 and 16 positive ionizing pulses, and a negative
pulse train comprising between approximately 2 and 16positive ionizing pulses, with
time interval between the positive pulses, with time interval between the positive
and negative pulse trains that is equal to approximately 2 times the period of consecutive
pulses.
[0059] The flowchart in Fig. 3 shows feedback algorithm 300 of the system 200, in accordance
with an embodiment of the invention. The function of providing ion balance control
by use of the feedback algorithm 300 runs at the end of an ionization cycle. This
algorithm is performed by, for example, the system 200 in Figure 2. In block 301,
the balance control feedback algorithm is started.
[0060] In blocks 302, 303, 304, and 305, the calculation of the control value of the negative
pulse width is performed. In block 302, an error value (Error) is calculated by subtracting
the desired ion balance (SetPoint) from the measured ion balance (BalanceMeasurement).
In block 303 the error value is multiplied by the loop gain. In block 304, the calculation
of the control value is limited to minimum or maximum values so that the control value
is limited and will not be out of range. In block 305, the control value is added
to the last negative pulse width value.
[0061] In blocks 306, 307, 308, and 309, the pulse width is incremented or decremented.
In block 306, the negative pulse width is compared with a maximum value (MAX). If
the negative pulse width is equal to MAX, then in block 307, the positive pulse width
is decremented and the algorithm 300 proceeds to block 310. If the negative pulse
width is not equal to MAX, then the algorithm 300 proceeds to block 308.
[0062] In block 308, the negative pulse width is compared with a minimum value (MIN). If
the negative pulse width is equal to MIN, then in block 309, the positive pulse width
is decremented and the algorithm 300 proceeds to block 310. If the negative pulse
width is not equal to MIN, then the algorithm 300 proceeds to block 310. When the
negative pulse width hits its control limit, a change in the Positive pulse width
will shift the balance in such a way as to over shoot the balance setpoint, forcing
the Negative pulse to its limit.
[0063] In blocks 310, 311, 312, and 313, the pulse repetition rates (Rep-Rates) are incremented
or decremented when pulse width limits are met. In block 310, the positive pulse width
is compared with MAX and the negative pulse width is compared with MIN. If the positive
pulse width is equal to MAX and the negative pulse width is equal to MIN, then in
block 311, alternately, the positive pulse repetition rate (Rep-Rate) is incremented
OR the negative pulse Rep-rate is decremented. The algorithm 300 proceeds to block
314. If the positive pulse width is not equal to MAX and the negative pulse width
is not equal to MIN, then the algorithm 300 proceeds to block 312.
[0064] In block 312, the positive pulse width is compared with MIN and the negative pulse
width is compared with MAX. If the positive pulse width is equal to MIN and the negative
pulse width is equal to MAX, then in block 313, alternately, the positive pulse repetition
rate (Rep-Rate) is decremented OR the negative pulse Rep-rate is incremented. The
algorithm 300 proceeds to block 314. If the positive pulse width is not equal to MIN
and the negative pulse width is not equal to MAX, then the algorithm 300 proceeds
to block 314.
[0065] The Positive and Negative Pulse width control is used when the balance is close to
the setpoint. As the emitter points age or as the environment dictates, the Positive
and Negative Pulse width control will not have the range and will "Hit" is control
limit (Positive at its Maximum and Negative at its Minimum (or vice versa)). When
this happens the algorithm changes the Positive or Negative Rep-Rate, effectively
increasing or decreasing the amount of On-Time of the Positive or Negative ion generation
and shifts the balance toward the setpoint.
[0066] In blocks 314, 315, 316, and 317, the pulse repetition rates (Rep-Rates) are incremented
or decremented when pulse width limits are met. In block 314, the positive pulse Rep-Rate
is compared with a minimum pulse repetition rate value (MIN-Rep-Rate) and the negative
pulse Rep-Rate is compared with a maximum pulse repetition rate value (MAX-Rep-Rate).
If the positive pulse Rep-Rate is equal to MIN-Rep-Rate AND the negative pulse Rep-Rate
is equal to MAX-Rep-Rate, then in block 315, one negative pulse is shifted to a positive
pulse through an offtime count, and the algorithm 300 then proceeds to block 318 during
which the balance control feedback algorithm 300 ends. An offtime count is when the
ionization waveform is off. The off-time is the time between negative and positive
and positive and negative group (or train of pulses) of pulses and is defined here
as a count, equal to a pulse duration with a Positive or Negative Rep-Rate.
[0067] If the positive pulse Rep-Rate is not equal to MIN-Rep-Rate AND the negative pulse
Rep-Rate is not equal to MAX-Rep-Rate, then the algorithm 300 proceeds to block 316.
[0068] In block 316, the positive pulse Rep-Rate is compared with MAX-Rep-Rate and the negative
pulse Rep-Rate is compared with MIN-Rep-Rate). If the positive pulse Rep-Rate is equal
to MAX-Rep-Rate AND the negative pulse Rep-Rate is equal to MIN-Rep-Rate, then in
block 317, one positive pulse is shifted to a negative pulse through an offtime count,
and the algorithm 300 then proceeds to block 318 during which the balance control
feedback algorithm 300 ends. If the positive pulse Rep-Rate is not equal to MAX-Rep-Rate
AND the negative pulse Rep-Rate is not equal to MIN-Rep-Rate, then the algorithm 300
proceeds to block 318 during which the algorithm 300 ends.
[0069] When the Rep-Rate control hits the limit, the algorithm triggers the next adjustment
control level.
[0070] Shifting a micro pulse from Positive pulse group to Off-Time pulse group to Negative
pulse group, shifts the balance in the Negative direction. Conversely, shifting a
micro pulse from Negative pulse group to Off-Time pulse group to Positive pulse group,
shifts the balance in the positive direction. Using the Off-Time group reduces the
effect, and thus provides a finer control.
[0071] A flowchart in Figure 4 shows an algorithm 400 of a micropulse generator control.
Waveforms of driving pulses and a high voltage output illustrated in the diagram of
Figure 8. This algorithm 400 is performed by, for example, the system 200 in Figure
2. In block 401, an interrupt service routine of Timer1 is started. The algorithm
400 for the micropulse generator runs, for example, every 0.1 milliseconds.
[0072] In block 402, a micropulse repetition rate counter is decremented. This counter is
the repetition rate divider counter of Timer1. Timer1 is the main loop timer and pulse
control timer running at 0.1ms. Timer1 turns on the HVPS output, thus the start of
the micro pulse, where TimerO turns off the HVPS, ending the micro pulse. Therefore,
Timer1 sets the rep-rate and triggers the Analog to digital conversion, TimerO set
the micro pulse width.
[0073] In block 403, a comparison is performed if the micropulse repetition rate counter
is equal to 2. In other words, a test is performed to determine if the Rep-Rate divider
count is 2 count from the start of the next micropulse. The step in block 403 will
synchronize the ADC (in the microcontroller 201) to a time just before the next micropulse
transmission. If the micropulse repetition rate counter is equal to 2, then the sample
and hold circuit 205 is set to sample mode as shown in block 404. In block 405, the
ADC in the microcontroller 201 reads the sensor input signal from the sample and hold
circuit 205.
[0074] If the micropulse repetition rate counter is not equal to 2, then the algorithm 400
proceeds to block 406.
[0075] Blocks 404 and 405 starts and performs the Analog-to-Digital conversion to permit
the microcontroller 201 to measure the analog input received from the sample and hold
circuit 205.
[0076] When the sample and hold circuit 205 is enabled, typically at approximately 0.2 milliseconds
before the next micro-pulse occurs at block 403 with the micropulses 803 and 804 having
pulse widths 810 and 811, respectively, the signal 250 (Figure 2) is then conditioned
by the low pass filter 206 and amplified by amplifier 207 before being applied to
the input of the Analog to Digital Converter (ADC) residing inside the Microcontroller
201. Just after the sample and hold circuit 205 is enabling (block 404) a sample and
hold operation, the ADC is signaled to start a conversion (block 405). The resulting
sample rate of the balance signal is typically about 1.0 millisecond, and in synchronization
with the micropulse repetition rates (rep-rate). However, the actual sample rate varies
as rep-rate 812, 813 (Figure 8) varies (as shown in blocks 310, 311, 312, 313) but
will always remain in synchronization with the micropulse rep-rate 812, 813.
[0077] According to this embodiment, the method of signal sampling before the next micropulse
allows the system 200 to ignore noise and current surges (capacitive coupled) and
advantageously avoid corrupting the ion balance measurement.
[0078] In block 406, a test is performed to determine if the Rep-Rate divider counter of
Timer1 s ready to begin the next micropulse. A comparison is performed if the micropulse
repetition rate counter is equal to zero. If the micropulse repetition rate counter
is not equal to zero, then the algorithm 400 proceeds to block 412. If the micropulse
repetition rate counter is equal to zero, then the algorithm 400 proceeds to block
417.
[0079] In block 417, the micropulse repetition rate counter is reloaded from data registers.
This will reload the time interval for the start of the next pulse (micropulse). The
algorithm 400 then proceeds to block 408.
[0080] Blocks 408, 409, and 410 provide steps that determine if a new Pulse Phase is started
or to continue the current Pulse Phase.
[0081] In block 408, a comparison is performed if the micropulse counter is equal to zero
(0).
[0082] If so, then the algorithm 400 proceeds to block 410 which calls the next pulse phase,
and the algorithm 400 proceeds to block 411.
[0083] If not, then the algorithm 400 proceeds to block 409 which calls to continue the
present pulse phase.
[0084] In block 411, the TimerO (micropulse width counter) is started. The TimerO controls
the micropulse width, as discussed below with reference to blocks 414-417.
[0085] In block 412, all system interrupts are enabled. In block 413, the interrupt service
routine of Timer1 is ended.
[0086] When the TimerO time expires, the actual micropulse width is controlled based on
blocks 414-417. In block 414, the interrupt service routine of TimerO is started.
In block 415, the positive micropulse drive is set to off (i.e., the positive micropulses
are turned off). In block 416, the negative micropulse drive is set to off (i.e.,
the negative micropulses are turned off). In block 417, the interrupt service routine
of TimerO is ended.
[0087] As also shown in portion 450 in Figure 400, for a micropulse drive signal 452, the
duration of TimerO is equal to the micropulse width 454 of micropulse drive signal
452. The micropulse width 454 begins at pulse rising edge 456 (which is triggered
at the start of the TimerO) and ends at the pulse falling edge 458 which is triggered
at the end of the Timer0).
[0088] Details of a method 700 of averaging the ion balance sensor input are shown in flowchart
in Figure 7. Blocks 701-706 describes the operations of the sample and hold circuit
205 and ADC conversion of data from the sample and hold circuit 205. At the end of
the ADC conversion 701, about 0.1 milliseconds later, the sample and hold block 205
is disabled, preventing the noise and current surges from corrupting the balance measurement.
The resulting measurement 703 and Sample Counter 705 are added to the previous Raw
Measurement Sum 704 value and saved, waiting further processing. Blocks 707-716 is
an averaging routine for averaging the measurements of the air ionization voltage
sensor 101 and/or ionization return current sensor 204 and obtains an Ion Balance
Measurement Average that is then combined using a Finite Impulse Response calculation
to combine the Balance Measurement Average with previous measurements 714 yielding
the a final Balance Measurement used in the balance control loop. The calculation
in block 714 calculates a weighted average from a previous series of sensor input
measurements. In block 715, an event routine is called to make an adjustment on the
ion generation based on the calculation in block 714.
[0089] The flowcharts in Figures 5A, 5B, and Figure 6 illustrate system operation during
formation of negative and positive polarity pulse trains. An Ionization cycle 531
is comprised of a series of positive pulses 502, 602, followed by an off time interval
503, 603, followed by a series of negative pulses 517, 604 followed by an off time
interval 518, 605. When the specified number of Ionization cycles has occurred 708,
the Ion Balance Measurement Average is calculated 709, and the Raw Measurement Sum
710 and Sample Counter values are cleared 710, 711.
[0090] Reference is now made to Figures 5A, 5B, and 6. These figures are flowcharts of a
system operation during the formation of a negative pulse train and a positive pulse
train, respectively in accordance with an embodiment of the invention. In block 501,
the routine of the next pulse phase for a negative pulse train is started. Blocks
502-515 describe the steps for generating negative series of pulses and the off time
of the pulse duration. Blocks 517-532 describe the steps for generating positive series
of pulses and the off time of the pulse duration. Blocks 601-613 describe the steps
for generating the next pulse phase or if the present pulse phase continues.
[0091] The Balance Measurement Average is then combined using a Finite Impulse Response
calculation to combine the Balance Measurement Average with previous measurements
714 yielding the a final Balance Measurement used in the balance control loop.
[0092] The balance control loop 301 compares the Balance Measurement to the set point value
302 yielding an error value. The Error signal is multiplied by the loop gain 303,
checked for over/under range 304 and added to the present Negative Pulse Width value.
[0093] In the micropulse HV supply system 202, 203, the pulse width of the driving micropulse,
changes the peak amplitude of the resulting High Voltage (HV) wave 814, 801, 802.
In this case the negative pulse amplitude is change to effect a change in the Ion
Balance. If the error signal value is greater than zero, the Negative pulse width
is adjusted up, thus increasing the negative HV pulse amplitude as a result, changing
the balance in the negative direction. Conversely, if the balance is negative, the
Negative pulse width is adjusted down, thus changing the balance in the positive direction.
[0094] During continual adjustments of the Negative pulse width and as conditions warrant,
the Negative pulse width may hit its control limit. In this situation the Positive
pulse width is adjusted down 307 for a positive out-of-balance or up 309 for a negative
out-of-balance until the Negative pulse width can again resume control. This method
of control using the Negative and Positive pulse width yields an average balance control
adjustment range of approximately 10V with a stability of less than 3V.
[0095] According to another embodiment under large out-of-balance conditions, for instance
at the Ionizing blower start up, significant contamination builds up or erosion of
the emitter(s) as the they ages, the Negative pulse width and the Positive pulse width
will reach their control limits 310, 312. In this situation, the Positive pulse repetition
rate and the Negative pulse repetition rate are adjusted 311, 313 to bring the balance
to the point where the Positive pulse width and Negative pulse width are once again
in their respective control ranges. Therefore, for a large positive out-of-balance
condition the Negative pulse repetition rate is increased 313, resulting in a negative
shift in balance. If the condition still exists, the Positive pulse repetition rate
is decreased 313, also resulting in a negative shift in balance. This alternating
method of changing the Positive/Negative rep-rate 313 continues until the Negative
pulse width and the Positive pulse width are once again within their control ranges.
Likewise, for a for a large negative out-of-balance condition the Positive pulse repetition
rate is increase 311 alternately the Negative pulse repetition rate is decreased 311
resulting in a positive shift in balance. This continues, as before, until the Negative
pulse width and the Positive pulse width are once again within their control ranges.
[0096] In the case where an extreme out-of-balance condition exists, the both the Negative/Positive
pulse width and Positive/Negative rep-rates adjustments may have hit their respective
control limits 310,312 314, 316, the Positive pulse count and the Negative pulse count
will then be changed to bring the balance to a point where the Positive/Negative rep-rates
are once again within their respective control ranges. Therefore, for an extreme positive
out-of-balance condition the Positive pulse count will decrease 317 and the Off-time
Pulse Count 317 will be increased by one pulse count, resulting in a negative change
in balance.
[0097] If the condition is still exists, the Off-time Pulse count will be decreased 317
and the Negative pulse count will increase 317 by one pulse count, resulting in a
further negative change in balance. This shifting of one pulse from negative to positive
packets /trains continues until the Positive/Negative rep-rate is once again within
their control ranges. Likewise, for a for an extreme negative out-of-balance condition
one pulse at a time will be shift from the positive pulse 315 packet/train through
the off-time pulse count to the negative pulse packet 315 resulting in a positive
change in balance until the Positive/Negative rep-rate are once again within their
control ranges.
[0098] In a parallel process, the Balance Measurement is compared to the setpoint. If the
Balance Measurement is determine to be outside its specified range, corresponding
to an average CPM (Charge plate monitor) reading of +/-15V measured at 1 foot from
the ionizer, the control system of the Ionizer will trigger a balance alarm.
[0099] In Figure 9 is method for providing a feedback routine that actuates an ion balance
alarm if an ion imbalance is present. Blocks 901-909 performs measurements that are
compared with threshold values to determine if a balance alarm is actuated. Blocks
910-916 determines if a balance alarm is actuated
[0100] In a timed interval of once every 5 second, the Balance Measurement is evaluated
903, when outside this range a "1" is left shifted into the Alarm register 904 otherwise
a "0" left shifted into the Alarm register 902. When the Alarm register contains a
value of 255 (all "1"s) the Balance Measurement is declared in alarm. Likewise if
the Alarm register contains a value of 0 (all "0"s) the Balance Measurement is declared
not in alarm. Any value of the Alarm register not 255 or 0 is ignored and the state
of the alarm is unchanged. This filters the Alarm notification and prevents sporadic
notifications. As a byproduct, the notification delay allows sufficient time for the
Balance control system to recover from external stimulus.
[0101] In another parallel process running at the end of each ADC conversion cycle, about
every 1 milli-second figure 9B, the balance control system is monitored. This routine
910 checks the Positive and Negative pulse counts for limit condition 911, 912. As
stated above, when an out-of-balance condition exists and the Positive/Negative pulse
width and the Positive/Negative rep-rate are at their respective limits, the Positive
and Negative pulse counts are adjusted. However in the event the Balance cannot be
brought back into the specification the and the Positive/Negative pulse counts have
reached their adjustment limit 911 912, an alarm state is force by setting the Alarm
register to a value of all "1"s 913, setting the Alarm flag 914, and setting both
alarm status bits 915.
[0102] The method and technic of automatic balance control discussed above is not limited
to one type of ionizing blower. They can be used in different models of ionizing blowers
with variety emitter electrodes. Other applications of the automatic system include
models of ionizing bars with micro-pulse high voltage power supplies.
1. A method of automatically balancing ionized air stream created in bipolar corona discharge,
the method comprising:
providing an air moving device (100) with at least one ion emitter (102) and at least
one reference electrode (104, 105) connected to a micro-pulsed AC power source (230),
and a control system (201) with at least one ion balance monitor (101, 204, 205) and
corona discharge adjustment control; and
generating variable polarity groups of short duration ionizing micro-pulses;
wherein said micro-pulses are predominantly asymmetric in amplitude and duration of
both polarity voltages and a magnitude of at least one polarity ionizing pulses exceeds
the corona threshold, and said micro-pulses pulses are arranged to follow one another
in positive and negative pulse trains;
characterised in that to balance an ionized air stream, the method further comprises:
generating an ion balance signal (252) with said ion balance monitor (101, 204, 205);
comparing (302) the ion balance signal (252) with a setpoint signal (253) using said
control system (201); and
adjusting the micro-pulses in response to the comparison, said adjustment comprising:
varying (307, 309) a duration of ionizing pulses in said positive or negative pulse
trains;
varying (311, 313) a repetition rate of ionizing pulses in said positive or negative
pulse trains; or
varying (315, 317) a number of pulses in said positive or negative pulse trains.
2. A method according to claim 1, wherein adjusting the micro-pulses in response to the
comparison comprises:
varying (307, 309) a duration of ionizing pulses in said positive or negative pulse
trains;
varying (311, 313) a repetition rate of ionizing pulses in said positive or negative
pulse trains if a pulse width control limit is reached (310, 312); and
varying (315, 317) a number of pulses in said positive or negative pulse trains if
a pulse repetition rate control limit is reached (314, 316).
3. A method according to claim 1, wherein a duration of at least one polarity of said
micro-pulses is at least 100 times shorter than a time interval between micro pulses.
4. A method according to one of the preceding claims, further comprising:
performing ion balance monitoring during time periods between said micro-pulses.
5. A method according to one of the preceding claims, further comprising:
performing an ion balance monitoring by integrating differential signals of said positive
and negative convection currents.
6. An apparatus for an automatically balanced ionizing blower, comprising:
an air moving device (100) with at least one ion emitter (102), and at least one reference
electrode (104, 105) both connected to a high voltage source;
an ion balance monitor (101, 204, 205);and
a control system (201);
wherein a transformer (203) of said high voltage source, said at least one ion emitter
(102) and said at least one reference electrode (104, 105) are arranged in a closed
loop current path for AC current circuit and said closed loop current path is connected
to ground by a resistor (R2);
wherein the high voltage source is configured to apply a high voltage output to said
at least one ion emitter (102) and wherein said high voltage output comprises both
positive polarity and negative polarity ionizing micro-pulses;
wherein said micro-pulses are predominantly asymmetric in amplitude and duration of
both polarity voltages and a magnitude of at least one polarity ionizing pulses exceeds
the corona threshold, and said micro-pulses are arranged to follow one another in
positive and negative pulse trains;
characterised in that to balance an ionized air stream:
said ion balance monitor (101, 204, 205) is configured to generate an ion balance
signal (252); and
said control system (201) is configured to:
compare (302) the ion balance signal (252) with a setpoint signal (253) using said
control system (201); and
adjust the micro-pulses in response to the comparison, said adjustment comprising:
vary (307, 309) a duration of ionizing pulses in said positive or negative pulse trains;
vary (311, 313) a repetition rate of ionizing pulses in said positive or negative
pulse trains; or
vary (315, 317) a number of pulses in said positive or negative pulse trains.
7. A apparatus according to claim 6 4 , wherein to adjusting the micro-pulses in response
to the comparison said control system (201) is configured to:
vary (307, 309) a duration of ionizing pulses in said positive or negative pulse trains;
vary (311, 313) a repetition rate of ionizing pulses in said positive or negative
pulse trains if a pulse width control limit is reached (310, 312); and
vary (315, 317) a number of pulses in said positive or negative pulse trains if a
pulse repetition rate control limit is reached (314, 316).
8. An apparatus according to claim 6, wherein the ion balance monitor includes a high
impedance voltage sensor (101) connected to an ion balance control system (107, 200)
and installed downstream to the ion emitter (102) at an outlet of said air moving
device (103).
9. An apparatus according to any one of claims 6 to 8, wherein an ion balance control
system (107, 200) is configured to sample output signals from said resistor (R2) and/or
voltage sensor (101) in a time interval between the ionizing pulses.
10. An apparatus according to one of claims 6 to 9, wherein said high voltage source is
configured to generate an output comprising a duration of at least one polarity of
said micro-pulses of at least 100 times shorter than a time interval between micro
pulses.
1. Verfahren zum automatischen Ausgleichen eines ionisierten Luftstroms, der in einer
bipolaren Koronaentladung erzeugt wird, wobei das Verfahren Folgendes aufweist:
Bereitstellen einer Luftbewegungsvorrichtung (100) mit mindestens einem Ionenemitter
(102) und mindestens einer Referenzelektrode (104, 105), die mit einer mikrogepulsten
Wechselstromquelle (230) verbunden ist, und eines Steuersystems (201) mit mindestens
einer Ionenausgleich-Überwachungseinrichtung (101, 204, 205) und einer Koronaentladung-Anpassungssteuerung;
und
Erzeugen von Gruppen variabler Polarität mit ionisierenden Mikroimpulsen kurzer Dauer;
wobei die Mikroimpulse in Amplitude und Dauer beider Polaritätsspannungen vorwiegend
asymmetrisch sind und eine Größe mindestens eines Polaritätsionisierungsimpulses den
Koronaschwellenwert überschreitet, und die Impulse der Mikroimpulse so ausgelegt sind,
dass sie aufeinander in positiven und negativen Impulsketten folgen;
dadurch gekennzeichnet, dass, zum Ausgleichen eines ionisierten Luftstroms, das Verfahren ferner Folgendes aufweist:
Erzeugen eines Ionenausgleichssignals (252) mit der Ionenausgleich-Überwachungseinrichtung
(101, 204, 205);
Vergleichen (302) des Ionenausgleichssignals (252) mit einem Sollwertsignal (253)
unter Verwendung des Steuersystems (201); und
Anpassen der Mikroimpulse in Reaktion auf den Vergleich, wobei die Anpassung Folgendes
aufweist:
Variieren (307, 309) einer Dauer von ionisierenden Impulsen in den positiven oder
negativen Impulsketten;
Variieren (311, 313) einer Wiederholungsrate von ionisierenden Impulsen in den positiven
oder negativen Impulsketten; oder
Variieren (315, 317) einer Anzahl von Impulsen in den positiven oder negativen Impulsketten.
2. Verfahren nach Anspruch 1, wobei das Anpassen der Mikroimpulse in Reaktion auf den
Vergleich Folgendes aufweist:
Variieren (307, 309) einer Dauer von ionisierenden Impulsen in den positiven oder
negativen Impulsketten;
Variieren (311, 313) einer Wiederholungsrate von ionisierenden Impulsen in den positiven
oder negativen Impulsketten, wenn eine Impulsbreitensteuergrenze erreicht wird (310,
312); und
Variieren (315, 317) einer Anzahl von Impulsen in den positiven oder negativen Impulsketten,
wenn eine Impulswiederholungsraten-Steuergrenze erreicht wird (314, 316) .
3. Verfahren nach Anspruch 1, wobei eine Dauer mindestens einer Polarität der Mikroimpulse
mindestens 100-mal kürzer als ein Zeitintervall zwischen Mikroimpulsen ist.
4. Verfahren nach einem der vorhergehenden Ansprüche, ferner aufweisend:
Durchführen einer Ionenausgleichsüberwachung während Zeiträumen zwischen den Mikroimpulsen.
5. Verfahren nach einem der vorhergehenden Ansprüche, ferner aufweisend:
Durchführen einer Ionenausgleichsüberwachung durch Integrieren von Differenzsignalen
der positiven und negativen Konvektionsströme.
6. Vorrichtung für ein automatisch ausgeglichenes ionisierendes Gebläse, aufweisend:
eine Luftbewegungsvorrichtung (100) mit mindestens einem Ionenemitter (102) und mindestens
einer Referenzelektrode (104, 105), die beide mit einer Hochspannungsquelle verbunden
sind;
eine Ionenausgleich-Überwachungseinrichtung (101, 204, 205); und
ein Steuersystem (201);
wobei ein Transformator (203) der Hochspannungsquelle, der mindestens eine Ionenemitter
(102) und die mindestens eine Referenzelektrode (104, 105) in einem Strompfad mit
geschlossenem Regelkreis für eine Wechselstromschaltung angeordnet sind und der Strompfad
mit geschlossenem Regelkreis durch einen Widerstand (R2) mit Masse verbunden ist;
wobei die Hochspannungsquelle konfiguriert ist, eine Hochspannungsausgabe an den mindestens
einen Ionenemitter (102) anzulegen, und wobei die Hochspannungsausgabe ionisierende
Mikroimpulse sowohl positiver Polarität als auch negativer Polarität aufweist;
wobei die Mikroimpulse in Amplitude und Dauer beider Polaritätsspannungen vorwiegend
asymmetrisch sind und eine Größe mindestens eines Polaritätsionisierungsimpulses den
Koronaschwellenwert überschreitet, und die Mikroimpulse so ausgelegt sind, dass sie
aufeinander in positiven und negativen Impulsketten folgen;
dadurch gekennzeichnet, dass zum Ausgleichen eines ionisierten Luftstroms:
die Ionenausgleich-Überwachungseinrichtung (101, 204, 205) konfiguriert ist, ein Ionenausgleichssignal
(252) zu erzeugen; und
das Steuersystem (201) konfiguriert ist zum:
Vergleichen (302) des Ionenausgleichssignals (252) mit einem Sollwertsignal (253)
unter Verwendung des Steuersystems (201); und
Anpassen der Mikroimpulse in Reaktion auf den Vergleich, wobei die Anpassung Folgendes
aufweist:
Variieren (307, 309) einer Dauer von ionisierenden Impulsen in den positiven oder
negativen Impulsketten;
Variieren (311, 313) einer Wiederholungsrate von ionisierenden Impulsen in den positiven
oder negativen Impulsketten; oder
Variieren (315, 317) einer Anzahl von Impulsen in den positiven oder negativen Impulsketten.
7. Vorrichtung nach Anspruch 6, wobei, zum Anpassen der Mikroimpulse in Reaktion auf
den Vergleich, das Steuersystem (201) konfiguriert ist zum:
Variieren (307, 309) einer Dauer von ionisierenden Impulsen in den positiven oder
negativen Impulsketten;
Variieren (311, 313) einer Wiederholungsrate von ionisierenden Impulsen in den positiven
oder negativen Impulsketten, wenn eine Impulsbreitensteuergrenze erreicht wird (310,
312); und
Variieren (315, 317) einer Anzahl von Impulsen in den positiven oder negativen Impulsketten,
wenn eine Impulswiederholungsraten-Steuergrenze erreicht wird (314, 316) .
8. Vorrichtung nach Anspruch 6, wobei die Ionenausgleich-Überwachungseinrichtung einen
Hochimpedanzspannungssensor (101) aufweist, der mit einem Ionenausgleich-Steuersystem
(107, 200) verbunden ist und stromabwärts des Ionenemitters (102) an einem Auslass
der Luftbewegungsvorrichtung (103) installiert ist.
9. Vorrichtung nach einem der Ansprüche 6 bis 8, wobei ein Ionenausgleich-Steuersystem
(107, 200) konfiguriert ist, Ausgangssignale von dem Widerstand (R2) und/oder dem
Spannungssensor (101) in einem Zeitintervall zwischen den ionisierenden Impulsen abzutasten.
10. Vorrichtung nach einem der Ansprüche 6 bis 9, wobei die Hochspannungsquelle konfiguriert
ist, eine Ausgabe zu erzeugen, die eine Dauer mindestens einer Polarität der Mikroimpulse
aufweist, die mindestens 100-mal kürzer als ein Zeitintervall zwischen Mikroimpulsen
ist.
1. Procédé d'équilibrage automatique d'un flux d'air ionisé créé dans une décharge corona
bipolaire, le procédé comprenant :
la fourniture d'un dispositif de déplacement d'air (100) avec au moins un élément
ionique (102) et au moins une électrode de référence (104, 105) connecté à une source
d'alimentation CA micro-impulsionnelle (230), et un système de commande (201) avec
au moins un dispositif de surveillance d'équilibre ionique (101, 204, 205) et une
commande d'ajustement de décharge corona ; et
la génération de groupes de polarité variable de micro-impulsions ionisantes de courte
durée ;
dans lequel lesdites micro-impulsions sont principalement asymétriques en amplitude
et en durée des deux tensions de polarité et une magnitude d'au moins une impulsion
ionisante de polarité dépasse le seuil corona, et lesdites micro-impulsions sont agencées
pour se succéder dans des trains d'impulsions positives et négatives ;
caractérisé en ce que pour équilibrer un flux d'air ionisé, le procédé comprend en outre :
la génération d'un signal d'équilibre ionique (252) avec ledit dispositif de surveillance
d'équilibre ionique (101, 204, 205) ;
la comparaison (302) du signal d'équilibre ionique (252) avec un signal de point de
consigne (253) à l'aide dudit système de commande (201) ; et
l'ajustement des micro-impulsions en réponse à la comparaison, ledit ajustement comprenant
:
la variation (307, 309) d'une durée d'impulsions ionisantes dans lesdits trains d'impulsions
positives ou négatives ;
la variation (311, 313) d'une fréquence de répétition d'impulsions ionisantes dans
lesdits trains d'impulsions positives ou négatives ; ou
la variation (315, 317) d'un nombre d'impulsions dans lesdits trains d'impulsions
positives ou négatives.
2. Procédé selon la revendication 1, dans lequel l'ajustement des micro-impulsions en
réponse à la comparaison comprend :
la variation (307, 309) d'une durée d'impulsions ionisantes dans lesdits trains d'impulsions
positives ou négatives ;
la variation (311, 313) d'une fréquence de répétition d'impulsions ionisantes dans
lesdits trains d'impulsions positives ou négatives si une limite de commande de largeur
d'impulsion est atteinte (310, 312) ; et
la variation (315, 317) d'un nombre d'impulsions dans lesdits trains d'impulsions
positives ou négatives si une limite de commande de fréquence de répétition d'impulsions
est atteinte (314, 316).
3. Procédé selon la revendication 1, dans lequel une durée d'au moins une polarité desdites
micro-impulsions est au moins 100 fois plus courte qu'un intervalle de temps entre
micro-impulsions.
4. Procédé selon l'une quelconque des revendications précédentes, comprenant en outre
:
la réalisation d'une surveillance d'équilibre ionique durant des périodes de temps
entre lesdites micro-impulsions.
5. Procédé selon l'une quelconque des revendications précédentes, comprenant en outre
:
la réalisation d'une surveillance d'équilibre ionique par l'intégration de signaux
différentiels desdits courants de convection positifs et négatifs.
6. Appareil pour une soufflerie ionisante automatiquement équilibrée, comprenant :
un dispositif de déplacement d'air (100) avec au moins un élément ionique (102), et
au moins une électrode de référence (104, 105) toutes deux connectées à une source
de haute tension ;
un dispositif de surveillance d'équilibre ionique (101, 204, 205) ; et
un système de commande (201) ;
dans lequel un transformateur (203) de ladite source de haute tension, ledit au moins
un élément ionique (102) et ladite au moins une électrode de référence (104, 105)
sont agencés dans un trajet de courant en boucle fermée pour un circuit de courant
CA et ledit trajet de courant en boucle fermée est connecté à la masse par une résistance
(R2) ;
dans lequel la source de haute tension est configurée pour appliquer une sortie haute
tension audit au moins un élément ionique (102) et dans lequel ladite sortie de haute
tension comprend à la fois des micro-impulsions ionisantes de polarité positive et
de polarité négative ;
dans lequel lesdites micro-impulsions sont principalement asymétriques en amplitude
et en durée des deux tensions de polarité et une magnitude d'au moins une impulsion
d'ionisation de polarité dépasse le seuil corona, et lesdites micro-impulsions sont
agencées pour se succéder dans des trains d'impulsions positives et négatives ;
caractérisé en ce que pour équilibrer un flux d'air ionisé : ledit dispositif de surveillance d'équilibre
ionique (101, 204, 205) est configuré pour générer un signal d'équilibre ionique (252)
; et
ledit système de commande (201) est configuré pour :
comparer (302) le signal d'équilibre ionique (252) avec un signal de point de consigne
à l'aide dudit système de commande (201) ; et
ajuster les micro-impulsions en réponse à la comparaison, ledit ajustement comprenant
:
varier (307, 309) une durée d'impulsions ionisantes dans lesdits trains d'impulsions
positives ou négatives ;
varier (311, 313) un fréquence de répétition d'impulsions ionisantes dans lesdits
trains d'impulsions positives ou négatives ; ou
varier (315, 317) un nombre d'impulsions dans lesdits trains d'impulsions positives
ou négatives.
7. Appareil selon la revendication 6,
dans lequel pour l'ajustement des micro-impulsions en réponse à la comparaison, ledit
système de commande (201) est configuré pour :
varier (307, 309) une durée d'impulsions ionisantes dans lesdits trains d'impulsions
positives ou négatives ;
varier (311, 313) une fréquence de répétition d'impulsions ionisantes dans lesdits
trains d'impulsions positives ou négatives si une limite de commande de largeur d'impulsion
est atteinte (310, 312) ; et
varier (315, 317) un nombre d'impulsions dans lesdits trains d'impulsions positives
ou négatives si une limite de commande de fréquence de répétition d'impulsions est
atteinte (314, 316).
8. Appareil selon la revendication 6, dans lequel le dispositif de surveillance d'équilibre
ionique comprend un capteur de tension à haute impédance (101) connecté à un système
de commande d'équilibre ionique (107, 200) et installé en aval de l'émetteur ionique
(102) à une sortie dudit dispositif de déplacement d'air (103).
9. Appareil selon l'une quelconque des revendications 6 à 8, dans lequel un système de
commande d'équilibre ionique (107, 200) est configuré pour échantillonner des signaux
de sortie provenant de ladite résistance (R2) et/ou dudit capteur de tension (101)
dans un intervalle de temps entre les impulsions ionisantes.
10. Appareil selon l'une des revendications 6 à 9, dans lequel ladite source de haute
tension est configurée pour générer une sortie comprenant une durée d'au moins une
polarité desdites micro-impulsions au moins 100 fois plus courte qu'un intervalle
de temps entre micro-impulsions.