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(11) | EP 1 128 710 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Apparatus for reducing energy dissipated by the power supply busbars of lighting systems |
| (57) The apparatus for reducing energy dissipated by the power supply busbars of lighting
systems, powered by AC supply mains (10) and aimed at supplying a loads (L1, ...,
Ln) system (90), includes at least one adjusting unit (A), powered by the above supply
mains (10), when said first switching means (4) are enabled, and aimed at powering
said loads (L1, ..., Ln) system (90) by a voltage, whose effective value is variable
with respect to the effective value of the supply voltage of the supply mains (10).
The apparatus includes also a bus (W) for direct supplying said loads system (90)
by said supply mains (10) when second switching means (3) are enabled. At least one
working unit (C) is aimed at allowing the management and control of the switching
means (3,4) and of the adjusting unit (A), so as to allow said loads (L1, ..., Ln)
system (90) to be supplied either by said adjusting unit (A). or by said bus (W). |
[0001] The present invention relates to the technical field concerning energy saving in lighting systems, particularly equipment including basically gas discharge lamps.
[0002] As it is known by those skilled in the field, most of the home lighting systems include mainly incandescent lamps, characterized by optimal duration, dimensions, chromatic yield as well as by low system costs.
[0003] However, most of public and industrial lighting systems include gas discharge lamps and/or fluorescent lamps, which are more efficient sources of light and are used to obtain operation low costs and high illumination degree and also because they can remain turned on for long periods of time.
[0004] This is particularly advantageous in big working environments, like sheds and vast open spaces, and in all cases which require high specific powers for lighting big surfaces concentrating the luminous power on few limited areas.
[0005] Very high specific efficiency of the above discharge light sources usually makes up for their bad chromatic yield. The above mentioned discharge lamps are also reliable due to their simple and functional working principle.
[0006] Recent advertisement and/or information campaigns promoted by the mass media and Italian and European Community institutions, have tried to make the public opinion sensitive to ecological education.
[0007] The object of the awakening campaigns is to protect health and surrounding environment by reducing acoustic and smog pollution rate, which, according to some medical studies, are responsible for many illnesses afflicting human race.
[0008] From this point of view, and first of all, because the coal seams are being run out and the oil prices are continuously increasing, the energy saving has been discussed on all society levels as a fundamental way of respect for environment.
[0009] Actually, a correct and wise energy conservation allows to reduce the emission of toxic gases to the environment and to protect health of each member of high-risk category (elder people, women, children, etc.).
[0010] The object of the present invention is to propose an apparatus for reducing the energy dissipated by the power supply busbars of lighting systems, in particular including gas discharge lamps, which allows to prepare an efficient energy saving plan in every load condition, assuring minimum illumination standards required for specific areas.
[0011] Another object of the present invention is to propose a particularly strong and efficient apparatus, which ensures predetermined reliability parameters in every operation condition, without changing in any way the safety and functionality of the lighting system, in which it works.
[0012] Still another object of the present invention is to propose an apparatus obtained by simple, cheap, extremely functional and reliable technical solution which ensures correct working step.
[0014] The characteristic features of the present invention will be pointed out in the following description of a preferred, but not only embodiment, with reference to the enclosed drawing tables, in which:
- Figure 1 is a schematic functional diagram of a system, in which the proposed apparatus works;
- Figure 2 is a schematic view of a voltage-current characteristic curve of one of the components indicated with (L1,...Ln) in Figure 1;
- Figure 3 is a schematic circuit diagram of the system component indicated with V in Figure 1.
[0015] With reference to the enclosed drawings, the reference numeral 10 indicates AC supply mains, preferably supplied by a symmetrical three-phase system, including three phase terminals, indicated with R, S, T and a neutral conductor indicated with N.
[0016] A main section SP of the AC supply mains includes protection means 2, which allow the apparatus proposed by the present invention, to be powered or not.
[0017] The apparatus feeds a system 90 of "n" loads (L1, ..., Ln), which are e.g. gas discharge light sources.
[0018] The proposed apparatus includes an adjusting unit A powered by the AC supply mains 10 by first switching means 4 situated in the region of a primary section S1, downstream of the main section SP.
[0019] The adjusting unit A feeds the loads system 90 by voltages, whose effective values vary with respect to the effective value of the AC supply mains 10 tension.
[0020] A bus W is situated parallel to the adjusting unit A, for feeding directly the loads system 90 (L1, ..., Ln) by the AC supply mains 10, with interposition of second switching means 3 situated in a secondary section S2, connected in parallel to the primary section S1.
[0021] The apparatus includes also a working unit C, which ensures management and control of the adjusting unit A and of the first switching means 4 and the second switching means 3, so as to allow to feed the loads system 90(L1, ..., Ln) by the adjusting unit A, i.e. by the bus W.
[0022] The correct electric function parameters of the AC supply mains 10 (in particular the efficient tension value between the phase conductor and the neutral conductor) can be verified by a verification station V connected between the management and control unit C and the AC supply mains 10, either upstream or downstream of the main section SP, e.g. upstream (Figure 1).
[0023] Transmission means T, co-operating with the control unit C, allow a remote management of the control unit C by remote transmission of data processed thereby.
[0024] This is particularly advantageous if the control unit C is not easily accessible due to the territorial structure or missing local supervision.
[0025] The adjusting unit A includes a plurality of "m" outlet sections (Y1, ..., Ym), each of which is capable of supplying the loads system 90 with a voltage of a predetermined effective value.
[0026] Each of the outlet sections (Y1, ..., Ym) includes corresponding switching members (I1,...,Im), which operate, if enabled by the control unit C, only one of the outlet sections (Y1, ..., Ym) to supply a predetermined tension effective value to the loads system 90.
[0027] The above mentioned adjusting unit A can advantageously include a transformer, whose secondary winding has a number "m" of secondary coil outputs, i.e. a number of outputs equal to the number of outlet sections (Y1, ..., Ym).
[0028] In this case, it is possible to maintain the supply of the loads system 90 during the commutation operation between two outlet sections, e.g. Y1 and Y2, and to reduce the value of the electric current of the adjusting unit A during the above commutation phase, by a plurality of resistors R which are connectable in parallel to at least one outlet section, e.g. Y1, under control of the control unit C, by a corresponding switch member I*, connected in series with the plurality of resistors R.
[0029] In the beginning, the proposed apparatus supplies the loads (L1, ..., Ln) with the nominal voltage from the supply mains 10: this situation will be maintained until the loads electrodes are fully heated.
[0030] When the heating step is completed, the apparatus reduces the effective value of the voltage on the loads system 90.
[0031] In this case, the control unit C can set automatically and without changing the operation conditions of the loads (L1, ..., Ln), the power supply commutation by the adjusting unit A, e.g. with the outlet section Y1, enabling the energy flow according to the direction K.
[0032] Therefore, the control unit C commands, in rapid succession, the closure of the first switching means 4 and the switch member I1 connected to the outlet section Y1, and opening of the second switching means 3, cutting off the power flow in the direction J and enabling the power flow in direction K (Figurel).
[0033] Obviously, what above, must occur without any change of the operation conditions of the loads (L1, ..., Ln) and without contemporary supply of the loads with voltages of different effective values.
[0034] Likewise, if the energy flow in the direction K is to be commuted from the outlet section Y1 of the adjusting unit A to the outlet unit Y2 thereof, the switch member I* must be closed, so as to connect the plurality of resistors R to the adjusting unit A, the switch member I1 must be opened, so as to disconnect the outlet section Y1, the switch member 12 must be closed, so s to connect the outlet section Y2, and then, the switch member I* must be opened, so as to disconnect again the plurality of resistors R.
[0035] During the commutation from the outlet section Y1 to the outlet section Y2 (opening of the switch member I1 and closing of the switch member I2), it is advisable to maintain the plurality of resistors R connected, so as to avoid dangerous overcurrent on the loads during the commutation step.
[0036] Thus, the control unit C controls the adjusting unit A, so as to supply the loads system 90 by tensions, whose effective values are substantially decreasing with respect to the nominal values.
[0037] Likewise, the control unit C can control the adjusting unit A, so as to supply the loads system 90 by tensions, whose effective values are substantially increasing with respect to the nominal values.
[0038] This way, it is possible to save considerable amounts of energy, particularly in the conditions of lower voltage, also with limited reduction of the effective values of the supply tension fed at the outlet of the adjusting unit A.
[0039] The obtained energy saving is very interesting, as it is possible to save (with reference to the direct supply) about 20% during the first evening hours and about 40% during the morning hours of small traffic.
[0040] The adjusting unit A, advantageously constituted by a transformer, whose secondary coil has many outputs, can also be constituted by a plurality of electronic semiconductor devices, controlled or semi-controlled.
[0041] The proposed apparatus, independently from the adjusting unit A, allows to prepare and follow an efficient energy saving plan in any loading condition, assuring minimum photo-metric requirements of the specific environment.
[0042] Moreover, the proposed apparatus is particularly strong and efficient and ensures predetermined reliability in each operation conditions, without changing in any way the safety and functionality of the lighting system, in which it works.
1. Apparatus for reducing energy dissipated by the power supply busbars of lighting systems,
said apparatus being powered by AC supply mains (10) under control of protection means
(2), situated in correspondence to a main section (SP) and aimed at supplying a load
system (90) comprising loads (L1, ..., Ln), characterized in that it includes:
at least one adjusting unit (A), powered by the above supply mains (10), when enabled by first switching means (4), situated in correspondence to a primary section (S1), downstream of said main section (SP), said adjusting unit (A) being aimed at powering said loads (L1, ..., Ln) system (90) with a voltage, whose effective value is variable with respect to the effective value of the supply voltage of said supply mains (10);
a bus (W) for direct supplying said loads system (90) by said supply mains (10), when second switching means (3), situated in correspondence to a secondary section (S2), downstream of said main section (SP), are enabled;
at least one working unit (C), aimed at allowing the management and control of said first switching means (4) and said second switching means (3) and of said adjusting unit (A), so as to allow said loads (L1, ..., Ln) system (90) to be supplied by either said adjusting unit (A). or said bus (W).
2. Apparatus, according to claim 1, characterized in that it includes a verification station (V), connected between said supply mains (10)
and said management and control unit (C), said verification station (V) being aimed
at verifying the correct electric working parameters of said supply mains (10).
3. Apparatus, according to claim 1, characterized in that it includes transmission means (T), cooperating with said management and control
unit (C) and aimed at remote transmitting of data processed by said management and
control unit (C).
4. Apparatus, according to claim 1, characterized in that it includes a plurality of outlet sections (Y1,..., Ym), situated at the outlet of
said adjusting unit (A), each of said outlet sections (Y1,..., Ym) being aimed at
supplying said system of loads (90) with a voltage of a predetermined effective value
and being equipped with corresponding switching members (C1,..., Cm), which enable,
when said management and control unit (C) is enabled, the supply of said system of
loads (90) by only one of the outlet sections (Y1,..., Ym).
5. Apparatus, according to claim 4, characterized in that at least one outlet section of said plurality of outlet sections (Y1, ..., Ym) includes
a plurality of resistors (R), aimed at being connected in parallel thereto by means
of a relative switch member (C*) under control of said management and control unit (C), said plurality of resistors
(R) being aimed at allowing to maintain the supply of said system of loads (90) during
the commutation between at least two outlet sections (Y1, ..., Ym) and at limiting
the intensity of the electric current of said adjusting unit (A) during said commutation
phase.
6. Apparatus, according to claim 4, characterized in that said adjusting unit (A) includes a transformer, whose secondary coil includes a multiple
outputs configuration.
7. Apparatus, according to claim 4, characterized in that said adjusting unit (A) includes a plurality of electronic semiconductor devices.
8. Apparatus, according to claim 7, characterized in that said electronic semiconductor devices are semi-controlled.
9. Apparatus, according to claim 7, characterized in that said electronic semiconductor devices are controlled.
10. Apparatus, according to claim 1 or 4, characterized in that said management and control unit (C) controls said adjusting unit (A), so as to supply
said system of loads (90) by voltages, whose effective values are substantially decreasing
with respect to nominal values, when the load is smaller, and substantially increasing
with respect to nominal values, when the load is bigger.
11. Apparatus, according to claim 3, characterized in that said transmission means (T) include a GSM digital unit, which is capable of remote
transmitting of data using telephone channels.
12. Apparatus, according to claim 1, characterized in that said loads (L1, ..., Ln) are discharge light sources.