PULSED VOLTAGE SOURCE FOR GAS-CLEANING ELECTROFILTERS

Abstract

 A pulsed voltage source for gas-cleaning elec- trofilters comprises a step-up transformer (5), whose primary winding (4) is connected to a sinusoidal voltage source. To the controlling inputs (6) of the thyristor regulator (1) are connected the inputs of a control unit (7). To the corona and receiving electrodes (8, 9) of the gas-cleaning electrofilter (10) is connected a transmitter (11) of electric parameters of the gas-cleaning electrofilter, the output of which is connected to the input of the control unit (7). To the secondary winding (15) of the step-up transformer (5) are connected the inputs of a rectifying bridge (16) whose outputs are electrically connected to the electrodes (8, 9) of the gas-cleaning electrofil- ters. The source further comprises a capacitor (21) the first output of which is connected, through a choke coil (22) connected in series with an electronic switch (23) shunted by an oppositely connected rectifier (24), to the corona electrode (8) of the electrofilter (10). The second output of the capacitor (21) is connected to the receiving electrode (9) of the electrofilter (10). The output power contact (26) and the controlling inputs (27) of the electronic switch (23) are electrically connected to the outputs of the controlling unit (7) and the outputs of a pulse generator (28).

Description

Field of the Invention

[0001] The invention relates to the field of gas cleaning, and more specifically to pulse voltage supplies for electrostatic precipitators.

Frior Art

[0002] Widely known in the art is a pulse voltage supply for electrostatic precipitators (K.Porle et al."Snizhenie vybrosov potreblyaemoi energii s pomoshju impulsnogo pitania elektrofiltrov" International Conference on Electrostatic Precipitation, Nos. 12 - 15 , 1984, Kyoto, Japan, p. 77 ), comprising a step - up transformer with the primary thereof connected via a thyristor controller to a sine voltage supply. The thyristor gates in the thyristor controller are connected to the outputs of a control unit. The corona--forming and precipitating electrodes are connected to the inputs of an electrostatic precipitator parameters sensor, the output whereof is connected to the input of the control unit. The secondary of the step-up transformer is connected to the inputs of a bridje rectifier. The voltage supply further comprises a capacitor with the first lead thereof connected to the first input of the bridge rectifier and, via connected in series choke and parallel-opposition connected electronic key end gate, to the corona--forming electrode of the electrostatic precipitator, and with the second lead thereof connected to the precipitating electrode of the electrostatic precipitator and to the second input of the bridge rectifier. The terminal of a heavy-duty contact and the control input of the electronic key are connected to the output of a pulse generator.

[0003] At a disabled electronic key, the voltage across the electrostatic precipitator electrodes is approximately equal to the corona initiation voltage. The capacitor connected across the output of the bridge rectifier is charged to a voltage, the magnitude whereof is.set by the thyristor controller under control of a signal, arriving at the control input thereof from the output of the control unit and depending on the electric processes in the electrostatic precipitator. Enabling the electronic key initiates an oscillatory process in the oscillatory network "capacitor--electrostatic precipitator electrodes-choke" and the voltage across the electrostatic precipitator electrodes exceeds the voltage drop across the capacitor. Thus, a pulse voltage is generated at the electrostatic precipitator electrodes. In this voltage supply a spark or arc breakdown results in considerable overvoltage across its components: capacitor, electronic key, electrostatic precipitator electrodes, this impairing the voltage supply performance reliability. In operation, the electronic key may be enabled earlier than the thyristors of the thyristor controller. Under such conditions, a breakdown in the electrostatic precipitator at a voltage across its electrodes equal to the amplitude of the pulse voltage causes the voltage across the capacitor to drop to zero and the electronic key has to carry an emergency short-circuit. The thyristors in the controller are fired at a control angle equal to its settled value, so that in the oscillatory circuit "sine voltage supply - thyristor controller -- step-up transformer - bridge rectifier - capacitor" an oscillatory process is set up at which the voltage across the capacitor may substantially exceed its steady-state value.

Disclosure of the Invention

[0004] This invention is to solve the problem of providing a pulse voltage supply for electrostatic precipitators, wherein the electric interconnection of the control unit outputs and the electronic key inputs would allow an improvement of the gas cleaning efficiency, while providing reliable performance of the electrostatic precipitator.

[0005] This is achieved by that in the pulse voltage supply for electrostatic precipitators, comprising a step-up transformer with the primary thereof connected via a thyristor controller to a sine voltage supply, a control unit with the outputs thereof connected to the thyristor gates in the thyristor controller, a sensor of the electric parameters of the electrostatic precipitator with the inputs thereof connected to the corona-forming and precipitating electrodes of the electrostatic precipitator and with the. output thereof connected to the input of the control unit, a bridge rectifier with the inputs thereof connected to the secondary of the step-up transformer and with the first and second outputs thereof electrically connected to the corona-forming and precipitating electrodes of the electrostatic precipitator, a capacitor with the first lead thereof connected via connected in series choke and parallel-opposition connected electronic key and gate to the corona-forming electrode of the electrostatic precipitator, and with the second lead thereof connected to the precipitating electrode of the electrostatic precipitator, and a pulse generator with the outputs thereof electrically connected to the terminal of a heavy-duty contact and to the control input of the electronic key, according to the invention the outputs of the control unit are electrically connected to the terminal of the heavy-duty contact and to the control input of the electronic key.

[0006] It is expedient, that to increase the reliability of the electrostatic precipitator performance the pulse generator be provided with a synchronization input, with the output of the control unit directly connected to the synchronization input of the pulse generator, the outputs whereof are connected to the terminal of the heavy-duty contact and to the control input of the electronic key.

[0007] It is also advantageous, that to increase the reliability of the electrostatic precipitator performance the pulse voltage supply further comprise an inhibitory gate with the first input thereof connected to the output of the control unit and with the output thereof connected to the synchronization input of the pulse generator, and a threshold gate with the input thereof connected to the output of the electrostatic precipitator parameters sensor and with the output thereof connected to the second input of the inhibitory gate.

[0008] It is further suitable, that to reduce the overvoltage across components the pulse voltage supply for electrostatic precipitators be supllemented with a logic OR gate with the inputs thereof connected to the outputs of the control unit, a pulse shaper with the input thereof connected to the output of the logic OR gate, a logic AND gate with the first input thereof connected to the output of the pulse shaper, with the second input thereof connected to the output of the pulse generator, and with the outputs thereof connected to the terminal of the heavy-duty contact and to the control input of the electronic key.

[0009] This invention allows increasing the pulse voltage amplitude at the electrodes of the electrostatic precipitator, thus improving the efficiency of gas cleaning. At the same time the overvoltage across the supply components, caused by spark and arc discharge in the electrostatic precipitator, is reduced, the overall resulting being an improved performance reliability of the electrostatic precipitator.

[0010] Herein below this invention is illustrated by a detailed description of the pulse voltage supply for electrostatic precipitators with reference to specific embodiments thereof and to the accompanying drawings, wherein:

Fig.l shows the schematic diagram of the pulse voltage supply for electrostatic precipitators, according to the invention;

Fig.2 shows the schematic diagram of a second embodiment of the pulse voltage supply, according to the invention;

Fig.3 shows the schematic diagram of a third embodiment of the pulse voltage supply, according to the invention;

Fig.4a shows the output voltage of the sine voltage supply as a function of time;

Fig.4b shows the output voltage of the control unit as a function of time;

Fig.4c shows the voltage across the capacitor as a function.of time;

Fig.4d shows the output voltage of the pulse generator as a function of time;

Fig.4e shows the voltage at the electrostatic precipitator electrodes as a function of time;

Fig.4f shows the output voltage of the threshold gate as a function of time;

Fig.4g shows the output voltage of the pulse shaper as a function of time.

Preferred Embodiments

[0011] The pulse voltage supply for electrostatic precipitators comprises thyristor comtroller 1 (Fig.l) designed as parallel-opposition connected thyristors 2,3.

[0012] The output of thyristor controller 1 is connected to one terminal of primary 4 of step-up transformer 5. The first and second terminals of step-up transformer 5 primary 4 are connected via thyristor controller 1 to a sine voltage supply (not shown in the drawing), with the thyristor controller 1 control inputs 6 connected to the outputs of control unit 7. Control unit 7 is of the generally known design configuration (G.M.-A.Aliev, "Agregaty- pitaniya elektrofiltrovr" (Electrostatic precipitator power supplies), Moscow, Energoizdat Publisheres, 1981,. pp.96-97. - In Russian). The corona-forming and precipitating electrodes 8, 9 of electrostatic precipitator 10 are connected to the inputs precipitator parameters sensor 11 designed as a voltage divider with connected in series resistors 12,13 thereof connected in parallel to electrodes 8,9 of electrostatic precipitator 10. The first lead of sensor 11 is connected to corona-forming electrode 8 of electrostatic precipitator 10, the second lead of sensor 11 is connected to common bus 14.

[0013] The precipitating electrode 9 of electrostatic precipitator 10 is connected to common bus 14.

[0014] The output of precipitator parameters sensor 11 is connected to the input of control unit. 7.

[0015] Secondary 15 of step-up transformer 5 is connected to the inputs of bridge rectifier 16 designed with diodes 17, 18, 19, 20. The first output of bridge rectifier 16 is connected to the first lead of capacitor 21, the second lead of bridge rectifier 16 is connected to common bus 14.

[0016] The first lead of capacitor 21 is also connected via connected in series choke 22 and electronic key 23 to corona-forming electrode 8 of electrostatic precipitator 10. Electronic key 23 is shunted by connected in series opposition connected gate 24 and choke 25. The second lead of capacitor 21 is connected to common bus 14. Terminal 26 of the heavy-duty contact and control input 27 of electronic key 23 are driven from the outputs of pulse generator 28.

[0017] Pulse generator 23 is of the generally known design configuration (SU, A,249462).

[0018] The outputs of control unit 7 are connected to the input of pulse generator 23.

[0019] A reduction of the overvoltage level of the pulse voltage supply components is provided by a second embodiment of the pulse voltage supply for electrostatic precipitators, according to this invention.

[0020] In this embodiment primary 4 (Fig.2) of step-up transformer 5 is connected via thyristor controller 1 comprising parallel-opposition connected thyristors. 2, 3 to a sine voltage supply (not shown in. the drawing). Gates 6 of thyristors 2,3 in controller 1 are connected to the outputs of control unit 7. Secondary 15 of step-up transformer 5 drives bridge rectifier 16 designed with diodes 17,18,19, 20. The first output of bridge rectifier 16 is connected to corona-forming electrode 8 of electrostatic precipitator 10, the second output of bridge rectifier 16 is connected to common bus 14.

[0021] Corona-forming and precipitating electrodes 8,9 of electrostatic precipitator 10 are connected to the inputs of sensor 11. of the precipitator electric parameters, with sensor 11 leads connected, respectively, to corona-forming electrode 8 of electrost'atic precipitator 10 and to common bus 14 and with sensor 11 output electrically connected to the input of control unit 7.

[0022] Precipitating electrode 9 of electrostatic precipitator 10 is connected to common bus 14.

[0023] Capacitor 21 has one lead connected via connected in series choke 22 end electronic key 23 to corona-forming electrode 8 of electrostatic precipitator 10. Electronic key 23 is shunted by.connected in series opposite polarity gate 24 and choke 25. The other lead of capacitor 21 is connected to common bus 14. Terminal 26 of the heavy-duty contact and control input 27 of electronic key.23 are connected to the outputs of pulse generator 28, the synchronization input whereof via inhibitory gate 29 is electrically connected to the outputs of control unit 7. Inhibitory gate 29 has its first input connected to the output of control unit 7 and its second input connected to the output of threshold gate 30, the input whereof is connected to the output of precipitator electric parameters sensor 11 and the output whereof is connected to the synchronization input of pulse generator 28.

[0024] Inhibitory gate 29 is designed as a completely controllable switch with a transistor of logic AND gate.

[0025] Threshold gate 30 is designed with a Zener diode, dy- nistor or operational amplifier.

[0026] A third embodiment of the pulse voltage supply for electrostatic precipitators according to the invention may be used to reduce the overvoltage level across components of the pulse supply.

[0027] In this embodiment step-up transformer 5 (Fig.3) has its primary 4 connected via thyristor controller 1 to a sine voltage supply (not shown in the drawing). Thyristor gates 6 in thyristor controller 1 are connected to the outputs of control unit 7. Secondary 15 of step-up transformer 5 is connected to the inputs of bridge rectifier 16 designed with diodes 17,18,19,20. The first output of bridge rectifier 16 is connected via resistor 31 to corona-forming electrode 8 of electrostatic precipitator 10, the second output of bridge rectifier 16 is connected to common bus 14.

[0028] Corona-forcing and precipitating electrodes 8,9 of electrostatic precipitator 10 are connected to the inputs of precipitator electric parameters sensor II, the output whereof is connected to the input of control unit 7.

[0029] Precipitating electrode 9 of electrostatic precipitator 10 is connected to common bus 14.

[0030] Capacitor 21 has its first lead connected via diode 32 to the first output of bridge rectifier 16, with the cathode of diode 32 connected to the first capacitor 21 lead and the anode of diode 32 connected to the first input of bridge rectifier 16. The first lead of capacitor 21 is also connected via connected in series choke 22 and electronic key 23 to corona-forming electrode 8 of electrostatic precipitator 10. Electronic key 23 is shunted by connected in series opposite polarity gate 24 and choke 25. The second lead of capacitor 21 is connected to com- non bus 14.

[0031] The outputs of control unit 7 are electrically connected to terminal 26 of the heavy-duty contact and to the control input of electronic key 23 via connected in series logic OR gate 33, pulse shaper 34 and logic AND gate 35.

[0032] The first and second inputs of logic OR gate 33 are connected to the first and second outputs of control unit 7, the output of logic OR gate 33 is connected to the input of pulse shaper 34, designed with an operational amplifier and having its output connected to the first input of logic AND gate 35, the second input whereof is connected to the input of pulse generator 23. The first and second outputs of logic AND gate 35 are connected to terminal 26 of the heavy-duty contact and to control input 27 of electronic key 23.

[0033] The pulse voltage supply for electrostatic precipitators of this invention functions as follows.

[0034] Primary 4 (Fig.l) of step-up transformer 5, via thyristor controller 1, receives voltage U₁ (Fig.4a) from the sine voltage supply (not shown in the drawings). The voltage from the terminals of secondary 15 (Fig.1) of step--up transformer 5 arrives at the input of bridge rectifier 16, the output whereof is voltage with an amplitude and frequency determined by the firing angle α(Fig.4a) of thyristor controller 1. The signal from the output of sensor 11 is applied to the input of control unit 7 and contains data on the electric processes taking place in electrostatic precipitator 10, sucl. as corona discharge in electrostatic precipitator 10, dust particle charging, dust particle drift toward the precipitating electrode 9 in electrostatic precipitator 10, dust particle deposition on precipitating electrode 9 in electrostatic precipitator 10. Pulses U_i4 from the output of control unit 7 are passed to gates 6 of thyristors 2,3 in thyristor controller 1 and set the thyristor firing angle α. Enabling thyristors 2,3 in thyristor controller 1 at the moment of time t₁ (Fig.4a) causes voltage U₁ transformed by step--up transformer 5 and rectified by bridge rectifier 16 to be passed to electrodes 8,9 of electrostatic precipitator 10 and to charge the equivalent capacitance of the gap between the corona-forming electrode 8 and precipitating electrode 5 of electrostatic precipitator 10. At the same time capacitor 21 is charged via gate 24 to a voltage U_c (Fig.4c) equal to the amplitude value.

[0035] Simultaneously with U_i4 (Fig.4b) voltage pulses arriving from the output of control unit 7 (Fig.l) at the thyristor gates 6 in thyristor controller 1, voltage pulses U_i (Fig.4d) are passed to the input of pulse generator (Fig.l).

[0036] Output voltage pulses from pulse generator 28 are applied to terminal 26 of the heavy-duty contact and to control input 27 of electronic key 23, this causing oscillations in the interelectrode gap between electrodes 8,9 of electrostatic precipitator 10 and parallel to them connected capacitor 21, resulting in voltage pulses U_i (Fig.4e)

[0037] being superimposed onto pulsating voltage U₂.

[0038] Since voltage pulses U_; (Fig.4d) arrive at the input of electronic key 23 at the moment pulsating voltage U₂ across electrodes 8,9 is at a minimum value U_min (Fig.4e),

[0039] the amplitude of voltage pulses U_i (Figs 4a, e), equal to _Ui 2(U_a-U_min), is at a maximum. This results in a corona discharge of higher intensity, leading to an increased efficiency of dust particle charging and an increased efficiency of gas cleaning.

[0040] Arc or spark discharges in electrostatic precipitators 10, most probable at a maximal U_i pulse (Fig.4e) across electrodes 8,9 of electrostatic precipitator 10, at the moment of time t₁ voltage U_i across capacitor 21 (Fig.l) drops off to zero and the emergency value of short-circuit current flows through corona-forming and precipitating electrodes 8,9 of electrostatic precipitator 10 and through electronic key 23. The input and output signals of control unit 7 are zero and the next pulse (Fig.4b) fails to arrive from the output of pulse generator 28 (Fig.1) at terminal 26 of the heavy-duty contact and at control input 27 of electronic key 23.

[0041] On conclusion of the breakdown, at the moment of time ^t₂ voltage U_c (Fig.4c) across capacitor 21 (Fig.1) and voltage U₂ (Fig.4e) at the corona-forming and precipitating electrodes 8,9 of electrostatic precipitator 10 gradually rise, in accordance with the increase in firing angle (Fig. 4b) of thyristor controller 1; α'<α''<α''', from α - 0 at which the output signal of cnntrol unit 7 (Fig. 1) is zero to the value corresponding to the steady-state firing angle of thyristor controller 1.

[0042] Voltage pulses (Fig.4b) generated at the output of control unit 7 (Fig.1) are gradually increased in duration from zero to the steady-state duration. At the same time pulses (Fig.4d) from the output of pulse generator 28 arrive at terminal 26 of the heavy-duty contact and at control input 27 of electronic key 23. Voltage U_c (Fig.4c)

[0043] across capacitor 21 (Fig.1) and voltage U₂ (Fig.4e) at corona-forming and precipitating electrodes 8,9 of electrostatic precipitator 10 gradually increase, so that the mean value of voltage U₂ and the amplitude of the voltage pulse gradually attain their steady-state values, this reducing the level of overvoltage across electrodes 8,9 (Fig.1) of electrostatic precipitator 10, across capacitor 21 and across electronic key 23.

[0044] The second embodiment of the pulse voltage supply for electrostatic precipitators described herein above functions in a similar manner.

[0045] In case of a breakdown in the electrostatic precipitator, inhibitory gate 29 inhibits passage of a signal to the input of pulse generator 23 from the output of control unit 7.

[0046] The value of threshold voltage U_n in threshold gate 30 is set approximately equal to corona discharge.initiation voltage in electrostatic precipitator 10. At a voltage across the electrostatic precipitator exceeding threshold gate 30 generates at its output signal U_n (Fig.4f) allowing passage of voltage pulses from the output of control unit 7 to the input of pulse generator 28.

[0047] At a voltage across corona-forming and precipitating electrodes 8,9 of electrostatic precipitator 10 below the output signal of threshold gate ₃0 inhibits passage of pulses to the input of pulse generator 28 from the output of control unit 7. Only from the moment of time t₃ (Fig.4b), when the voltage across corona-forming and precipitating electrodes 3,9 (Fig.1) of electrostatic precipitator 10 exceeds the corona discharge initiation voltage U_k and the output signal of threshold gate 30 is U_n, pulses U_i4 from the output of control unit.7 are allowed to pass to the input of pulse generator 28, the next pulse arrives at terminal 26 of the heavy-duty contact and at control input 27 of electronic key 23, electronic key 23 is enabled and conjoint operation of control unit 7 and pulse generator 28 is restored.

[0048] The independent schematic diagrams of the control unit and of the pulse generator are brought into agreement in the third embodiment of the pulse voltage supply for electrostatic precipitators, which functions similar to the first embodiment.

[0049] Thyristor gates 6 in thyristor controller 1 receive pulses (Fig.4b ) from the output of control unit 7, these pulses setting firing angle α of thyristor controller 1 (Fig.3). Enabling of thyristor controller 1 causes voltage U₁ (Fig.4a) to be transformed by step-up transformer 5 (Fig.3), rectified by bridge rectifier 16 and applied via resistor 31 to electrodes 3,9 of electrostatic precipitator 10. Capacitor 21 is charged via diode 32 and gate 24 and voltage U_c (Fig.4c), to which the capacitor is charged, is equal to the voltage amplitude.

[0050] Voltage pulses (Fig.4b) arriving at gates 6 (Fig.3) in thyristor controller 1 from the output of control unit 7, are applied to the inputs of logic OR gate 33, at the output whereof a sum of the output signals of control unit 7 is generated and passed to the input of pulse shaper 34, which generates logic "1" U_i3 , pulses at its output, to be passed to the first input of logic AND gate 35. The second input of logic AND gate 35 receives pulses (Fig.4d)

[0051] from the output of pulse generator 28 (Fig.3). In case of time coincidence of these pulses, logic AND gate 35 generates output pulses passed to terminal 26 of the heavy--duty contact and to control input 27 of electronic gate 23. Enabling electronic key 23 causes oscillations in the circuit capacitor 21 - electrodes 3,9 of electrostatic precipitator 10, producing voltage pulses U_i (Fig.4e) superimposed on the pulsating rectified voltage.

[0052] In case of an arc or spark breakdown in the electrostatic precipitator, the output signal of control unit 7 (Fig.3) disappears, the output signal of pulse shaper 34 is a logic "0" passed to the first input of logic AND gate 35, so that there is no signal at the output thereof irrespective of the pulses at the second input thereof from the output of pulse generator 35..After control unit 7 begins generating pulses (Fig.4b), firing angle α gradually increases from zero to its steady-state value and pulse shaper 34 (Fig.3) generates logic "1" signals of a duration equal to the firing angle. Arrival of logic "1" signals at the first input of logic AND gate 35 and pulses (Fig.4d) at the second input thereof from the output of pulse generator 23 (Fig.3) produces voltage pulses at the output of logic AND gate 35 passed to terminal 26 of the heavy-duty contact and to control input 27 of electronic key 23. Electronic key 23 is enabled, voltage U_c (Fig.4c) across capacitor 21 (Fig.3) and voltage U₂ (Fig.4e) on corona-forming and precipitating electrodes 3,9 of electrostatic precipitator 10 gradually rise to their steady-state magnitudes.

[0053] Synchronization provided by coupling the outputs of control unit 7 to the input of pulse generator 23 ensures reliable performance of the pulse voltage supply under steady-state and transient conditions, because the time of firing angle increase from zero to its steady-state value is a halfwave of the voltage supplied by the sine voltage supply and this is sufficient for proper operation of control unit 7 and prevents generation of overvoltages on the pulse voltage supply components.

[0054] The use of this invention allows the pulse voltage supply performance reliability to be improved, and the mass and overall dimensions of its components to be reduced.

Industrial Applicability

[0055] This invention can be advantageously used in power engineering at thermal power plants, in ferrous metallurgy, in the cement industry, in construction materials manufacture.

Claims

1. A pulse voltage supply for electrostatic precipitators, comprising step-up transformer (5) with primary (4) thereof connected via thyristor controller (1) to a sine voltage supply, control unit (7) with the outputs thereof connected to thyristor gates (6) in thyristor controller (1), electrostatic precipitator electric parameters sensor (11) with the inputs thereof connected to corona-forming end precipitating electrodes (8,9) of electrostatic precipitator (10) and with the output thereof connected to the input of control unit (7), bridge rectifier (16) with the inputs thereof connected to secondary (15) of step-up transformer (5) and with the first and second outputs thereof connected to corona-forming and precipitating electrodes (3,9) of electrostatic precipitator (10), capacitor (21) with the first lead thereof connected via connected in series choke (22) and parallel--opposition connected electronic key (23) and gate (24) to corona-forming electrode (3) of electrostatic precipitator (10) and with the second lead thereof connected to precipitating electrode (9) of electrostatic precipitator (10), pulse generator (28) with the outputs thereof connected to terminal (26) of a heavy-duty contacts and to control input (27) of electronic key (23 ), characterized by that the outputs of control unit (7) are electrically connected to terminal (26) of the heavy--duty contact and to control input (27) of electronic key (23).

2. A pulse voltage supply for electrostatic precipitators as claimed in Claim 1, characterized by that pulse generator (28) is supplemented with a synchronization input whereto the output of control unit (7) is directly connected, with pulse generator (28) outputs connected to terminal (26) of the heavy-duty.contact and to control input (27) of electronic key (23).

3. A pulse voltage supply for electrostatic precipitators as claimed in Claim 1, characterized by that it further comprises inhibitory gate (29) with the first input thereof connected to the output of control unit ( 7 ) and with the output thereof connected to the synchronization input of pulse generator (23), and threshold gate (30) with the input thereof connected to the output of electrostatic precipitator electric parameters sensor (11) and with the output thereof connected to the second input.of inhibitory gate (25).

4. A pulse voltage supply for electrostatic precipitators as claimed in Claim 1, characterized by that it further comprises logic OR gate (33) with the inputs thereof connected to the outputs of control unit (7), pulse shaper (34) with the input thereof connected to the output of logic OR gate (33), logic AND gate (35) the first input thereof connected to the output of pulse shaper (34), with the second input thereof connected to the output of pulse generator (28), and with the outputs thereof connected to terminal (26) of the heavy--duty contact and to control input (27) of electronic key (23).

Drawing