EP0807311B1 - Device for voltage control - Google Patents

Abstract

A device for uninterrupted voltage control with an autotransformer has a first contact member (11), with which the load section (4) of the transformer can be bridged, and a second contact member (9), with which the primary winding (2) of the transformer can be deactivated. When switching over to changing the voltage to the consumer (6), both contact members (9, 11) are controlled in such a way that the load section (4) forms a choke.

Description

The invention relates to a lighting system with gas discharge lamps and an autotransformer uninterrupted voltage regulation of the Gas discharge lamps.

A street lighting system will be used during the evening rush hour generally with full Luminous intensity, i.e. operated with mains voltage, and in the quiet night time with reduced tension. With gas discharge lamps, switching from the Mains voltage to the reduced voltage and vice versa uninterrupted, otherwise the lamp will fail.

According to the state of the art, this is stepless adjustable transformers used, e.g. B. a Autotransformer that has an iron core with only one Has winding, the input side with the phase of Network and the neutral conductor and on the output side with one Tapping the transformer winding and the neutral conductor connected is. The voltage to be removed is indicated by Tap the line leading to the phase of the consumer leads, obtained on a turn of the winding. The Ratio of the voltage to be reduced to the nominal voltage corresponds to the ratio of the number of turns, between the output side of the winding and of the stripped turn to the total number the winding of the winding. The entire winding forms so the primary winding, during the winding section between the tap and the neutral Secondary winding of the savings transformer forms. Of the Winding section of the primary winding between the Phase of the network and the tap is also called Designated load section.

To make the transformer controllable, it is known to use bare wires for winding and for tapping a customer who runs along the Winding slides over the bare wires. Since the total load current flows over the customer, he must be trained accordingly expensive. Besides, is a motor necessary to move the customer, and the customer becomes through the sliding contact of the winding worn.

Furthermore, variable transformers are known in which the Winding is provided with taps. So while there is no interruption of switching and no short circuit of the turns to be switched on and off occurs in each branch between tapping and the supply line to the consumer two switching elements provided, the second switching element a Resistance bridged. The switching process begins with the fact that in the connected, first branch of the Resistor is turned on and then over an equal resistance in the other branch Connection is made with the new tap. The turns to be switched between the two Taps are now short-circuited in the Short circuit, however, are the two resistors and limit the short-circuit current. If so now first switching element is separated in the first branch, the new tap is already connected. Your direct connection to the outer supply line finally by closing the second switching element in the second branch reached. The well-known variable transformer with tap changer is through the two switching elements and the resistance at each tap is expensive and accordingly expensive.

To save electricity costs, it is known to Power regulation the power peaks caused by the accidental same turning on multiple devices arise, distribute. According to the state of the Technology for the devices, one control line each pulled and directly into the operation of each Device intervened, for example by clocked Switch off. The subsequent installation of Control lines, however, is significant Associated effort. This regulation is also for devices unsuitable with a more complicated mode of operation.

According to "Patent Abstracts of Japan", Vol. 007 No. 280, or JP-A-58159676 when starting an electric motor this only with a reduced voltage operated, which then gradually to full voltage is increased. For this purpose, an autotransformer is provided the branches at different winding sections has, which are connected by switching elements to the electric motor are. Another switching element connects the Transformer with the battery. When starting, the switching element to the battery and the switching element on the first Closed winding section, the other switching elements open. After a few seconds the closed ones Switching elements opened and the switching element on the second winding section closed. The transformer now acts as a throttle, and after some Seconds, the switching element to the battery is closed, which causes the voltage applied to the electric motor is about half the full voltage. Then the switching elements on the other Winding sections closed one after the other to the to increase voltage applied to the electric motor. Also the Circuit according to "Patent Abstracts of Japan", vol. 95, no. 001, or JP-A-07007978 is used to start an electric motor, which still has a resistor between one of the winding branches and the associated switching element is provided, whereby the Transformer can be built smaller.

The object of the invention is a simple structure To provide lighting system with gas discharge lamps, which is an uninterrupted voltage regulation of gas discharge lamps.

This is according to the invention with that in claim 1 marked lighting system reached.

In the Subclaims 2 to 7 are advantageous Embodiments of the invention reproduced.

One, the first switching element of the transformer The device according to the invention is preferably used for Bridging the load section of the transformer and the other switching element, the primary winding except To put operation. It can also be in the control section be provided. When switching to change the Voltage on the gas discharge lamps are the two Switching elements controlled so that the load section Throttle forms. In this way, the Gas discharge lamps when switching always with the Minimum voltage supplied. When switching between individual switching elements practically simultaneously takes place, the throttling effect can hardly bear come. The short circuit can then be so short that the short-circuit current cannot increase. The Switching elements can therefore be controlled so that a Short circuit is limited in time so that a Damage to the switching elements or lines is prevented.

With the controllable transformer there is the primary and / or Secondary winding preferably at least partly from individual sections, which in one of the combination corresponding to decreasing voltage are interconnectable. At least one section has the first switching element in its current path and the other between its entrance and the exit Switching element on. The switching elements are preferred by Sagittarius formed. Each section can have one Resistor, a choke and / or a fuse have, preferably a line with the one Switching element is provided with which the consumer the phase of the network can be connected. The further Switching element can be arranged in the line, which the load section on the output side with the consumer connects.

The transformer winding of the autotransformer has preferably one on the input side to the phase of Network and output side to the phase of the consumer connected load section and one connected on the output side to the neutral conductor Control section on, which at least partially from the Individual sections that exist in one of the combination with decreasing voltage the neutral are connectable. The tax section consists preferably of a first part and a second part. The second part is between the arranged first part and the load section. It is the number of turns connected to the neutral conductor of the second part unchangeable, while the number of turns of the first which can be connected to the neutral conductor Is partly changeable.

The consumer is one Lighting system with gas discharge lamps.

If the gas discharge lamps at full light intensity, So operating with mains voltage is the first Switching element closed and the second switching element open. If the Brightness reduced, that is Gear ratio of the transformer corresponding voltage drop, the first switching element opened and the second switching element getting closed. To do this is a certain one Switchover time necessary. The two switching elements are preferably by protection with make contacts and / or protection with make and break contacts. At protection as a switching element is the switchover time a few milliseconds. To prevent the lamp from failing prevent, therefore, according to the invention first a switching element in the primary circuit opened. So that goes the load section of the transformer, i.e. the Section over which the load current flows into a Throttle over. This way a failure of the Lamp prevented during the switching process. Then the further switching element is closed, whereby a the transformation ratio of the transformer sets the corresponding voltage drop.

The invention is based on the drawing explained in more detail, for example, in FIGS. 1 to 5 a different circuit of an autotransformer show according to the invention.

According to Figure 1, the autotransformer consists of a closed iron core 1 with a winding 2. Die entire winding 2 forms the primary winding of the Autotransformer, section 4 of winding 2 between phase L of the network and tap 3 of the Line 5 to the gas discharge lamp 6 provides the The load section represents the load current IL to the lamp 6 flows. The winding section 7 between the tap 3 and the neutral conductor N forms the secondary winding of the Autotransformer through which the magnetizing current IM and a compensation current dependent on the load flows.

The phase L of the network is via a bypass line 8 connected to line 5. The bypass line 8 has a first switching element 9, so that they at closed switching element 9 the load section 4th bridged. The output of the secondary winding 7 is with the neutral conductor N connected via a line 10, the one has second switching element 11.

The two switching elements 9 and 11 are by a Contactor, i.e. a remote-controlled electromagnetic Switch formed, preferably by the closer or opener of the same contactor, or by the two NO contacts of a contactor, as in the drawing shown.

The nominal voltage is designated U1, and the Load voltage with U2. When the switching element 9 opens and the switching element 11 is closed, that is at unactuated contactor, the lamp 6 with the by Transformer reduced voltage U2 <U1 operated. For switching the load voltage U2 to the nominal voltage U1 the contactor is actuated. The switching elements 9, 11, thus the NO and NC contacts of the contactor controlled so that the switching element 11 opened is before the switching element 9 is closed. In order to the load section 4 acts during the switching time of Protection for a short time, d. H. for example 5 to 50 Milliseconds as a choke. The throttle leads to a voltage drop. However, this is low, so that the lamp 6 during the switching process with a sufficient voltage U2 is supplied. After that closes the switching element 9, whereby the load section 4th or bridged the choke and thus the lamp 6 with the nominal voltage U1 is operated, that is U2 = U1.

If from the nominal voltage U1 to a reduced one The contactor is to be switched voltage U2 actuated so that the switching element 9 is opened, whereby the load section 4 forms a throttle. After that the contactor closes the switching element 11. This is a uninterrupted switching from U2 = U1 to U2 <U1 and vice versa possible.

If the nominal voltage z. B. is 220 V, can reduced voltage z. B. 180 V. In any case make sure that the reduced voltage U2 is greater is than that for operating the gas discharge lamp 6 required minimum voltage, preferably 5 V to 10 V greater than the minimum voltage to accommodate fluctuations in the Nominal voltage.

With U2 = U1, the load section 4 is the Bridged transformer and the primary winding 2 or the control section 7 is deactivated. At the Switch to the reduced voltage U2 <U1 and from the reduced voltage to the voltage U2 = U1 the two switching elements 9, 11 are each so controlled that the load section 4 a Gas discharge lamps 6 forms upstream choke.

FIG. 2 shows a transformer with a primary winding 12 and a secondary winding 13 on a closed one Iron core 1 shown. Through lines 15 and 16 this transformer is also switched as an economy transformer.

The secondary winding 13 forms the load section of the Transformer, i.e. the section over which the Load current IL flows via line 14 to lamp 6.

The secondary winding 13 has a bypass line 8 can be bridged with a first switching element 9.

The primary winding 12 is on the input side with the phase L of the network connected via a line 15 in which the second switching element 11 is arranged. The exit side the primary winding 12 is connected via a line 16 to the Neutral conductor N connected.

If the lamp 6 with a reduced voltage U2 <U1 is operated, the switching element 9 is open and that Switching element 11 closed. To switch to one Voltage U2 = U1 becomes the switching element 11, that is Contactor normally open first before that Switching element 9, i.e. the second NO contact of the contactor, is closed. During this switching time from the secondary winding 13 goes in a few milliseconds Throttle operation over, creating sufficient voltage to operate the lamp 6 is ensured. After that closes the switching element 9, whereby the lamp 6 with the Nominal voltage U1 is operated, ie U2 = U1.

When the load voltage U2 to a reduced voltage U2 <U1 is to be switched, the switching element 9 first opened so that the secondary winding 13 as Throttle acts, whereupon the switching element 11 is closed becomes.

That is, when U2 = U1, the secondary winding is 13 bridges the load section of the transformer, while the primary winding 12 is decommissioned is. When switching to the reduced voltage U2 < U1 and from the reduced voltage to U2 = U1 the two switching elements 9, 11 thus each so controlled that the secondary winding 13 one of the Gas discharge lamp 6 forms upstream choke.

An autotransformer is shown in FIG which the load voltage U2 can be finely regulated can. The secondary winding 7 of Figure 1 is there replaced by a control section 17.

The control section 17 is composed of a first part 18 and a second part 19 is formed. The turns of the second part 19 connect to the turns of the Load section 4. The turns of the first part 18 the control section 17 consist of several Sections I to IV.

Each individual section I to IV points in its current path a first switching element 24 to 27. Furthermore, a Switching element 28 to 31 between the input side E and the output side A of each section I to IV intended. From the input side E each Section I to IV leads a line 32 to 35 to the turns of the relevant section I to IV, with the first in lines 32 to 35 Switching element 24 to 27 is arranged. Another Line 36 to 39 leads from the turns of the each individual section I to IV to the Output side A of the same.

The input side E of the first individual section I is via a line 40 to the output side of the second Part 19 of the control section 17 connected while the output side A of the facing away from the second part 19 Section IV via a line 41 with the Neutral conductor N is connected, in line 41 that Switching element 11 is arranged. Between the lines 32 and 36, 33 and 37, 34 and 38 and 35 and 39 each Section I to IV are the Switching elements 28 to 31.

Each individual section I to IV has one different number of turns. For example, can the individual section I ten, the individual section II twenty, section III forty and the Individual section IV have eighty turns.

The number of turns NM of the Control section 17, which is connected to the neutral conductor are in accordance with the voltage U2 to be taken be changed. The number of turns NM of the The control section consists of the unchangeable Number of turns NM const. Of the second part 19 and changeable number of turns NM v of the individual sections I to IV, which are connected to the neutral conductor N.

That is, if, for example, the number of turns NM of the Control section 17 from the number of turns NM const second part 19 and the ten turns of Section I should put together, that will Switching element 24 of the individual section I closed and the switching element 28 between the input E and the Output A of section I opened while the Switching elements 25, 26, 27 of the remaining individual sections II to IV opened and the switching elements 29 to 31 between input E and output A of Sections II to IV are closed.

For example, if the number of turns NM of the Control section 17 NM constant plus seventy turns should be, the switching elements 24, 25, 26 of the Individual sections I to III closed and the Switching elements 28, 29, 30 between the input E and the Output A of sections I to III open, while the switching element 27 of the section IV opened and the switching element 31 between the input E and the exit A of the section IV closed becomes.

It can be seen that the individual sections I to IV according to Figure 3, the number of connected Turns in sixteen steps of ten turns each changes from zero to one hundred and fifty. Here each step corresponds to a specific change in Size of the voltage to be reduced.

For example, if the nominal voltage U1 is 220 V, the voltage to be decreased U2 for all connected four individual sections I to IV z. B. 210 V and the decreasing voltage U2 for all four switched off Individual sections I to IV, i.e. only with the turns of the second part 19 of the control section 17 z. B. 170 V, the voltage U2 can be between 170 V and 210 V can be changed in sixteen steps. The change in voltage at each stage is but not the same size. That is, it exists no linearity between the switched on Number of turns and change in size of the decreasing voltage U2.

The relationship between the number of turns NR connected and the voltage U2 to be taken off results from the following formula NR = NL x U2 (U1-U2) - NF where NL is the number of turns of the load section 4, U1 the nominal voltage and NF the unchangeable number of turns of the second part 19 of the control section 17.

Based on the formula (I), it was calculated that for example with six individual sections I to VI voltage U2 to be taken at a nominal voltage of 220 V from 120 V to 205 V approximately linear in 5 V steps can change if two turns in section I, five turns in section II, eleven turns in Section III, twenty-four turns in Section IV and fifty-four respectively one hundred and three turns in section V or VI are provided. In lighting systems, however a linear increase and decrease of U2 is often not required, sometimes even undesirable.

The total effective winding, i.e. H. the load section 4, the second part 19 of the control section 17 with the invariable number of turns NF as well as the switched turns NR of the first part 18 of the Control section 17 form the primary winding of the Saving transformers, while the second part 19 and the switched turns NR of the first part 18 die Form secondary winding. It can be seen that with that the primary and secondary winding for the economy transformer can be changed, depending on which Section I to IV interconnected and with the Neutral conductor N are connected.

The transformer can also be designed in three phases.

If, according to Figure 3, the first switching element 24 to 27 and the second switching element 28 to 31 the individual section I until IV are closed at the same time individual sections I to IV short-circuited, so that it can be destroyed. As switching elements 24 up to 31 can shooters, remote controlled electromagnetic switches are used that are inexpensive and millions of switches withstand.

When using contactors as switching elements 24 to 31 is a short interruption in the magnetizing current IM however inevitable. During the switchover time, so this brief interruption of, for example, a few The load section 4 acts as a choke for milliseconds the lamp 6. This is the lamp 6 during the Switching time applied a voltage that the Nominal voltage Ul minus the load voltage UL corresponds. That means if, for example, the nominal voltage is 220 V is and the load voltage is 5 V, and thus at Switch a voltage to the lamp 6 with a contactor of 215 V. A short twitch of the Light occur.

The two switching elements 24 and 28, 25 and 29, 26 and 30 and 27 and 31 of each section I to IV should switch on the one hand if possible, so that the twitching stops, on the other hand they are allowed not be closed at the same time because otherwise a Short circuit occurs.

The short-circuit current, however, needs a certain one Time from z. B. two to ten milliseconds until it turns fully built. Therefore, when switching elements 24 to 31 be used which have a very short switching time have, for example, a switching time that the Half or less of the build time for the Short-circuit current, there is a risk that a Short circuit to damage the concerned Section I to IV leads, significantly reduced.

The cheaper commercially available contactors are therefore readily usable if the mentioned Current peaks are accepted when switching, which is caused by a brief twitching of the lamp 6 express. The cheaper shooters are then however can no longer be used if switches 24 and 28, 25 and 29, 26 and 30 and 27 and 31 of the individual sections I to IV are operated simultaneously, even then, if the switching time of the contactors is shorter than that Construction time of the short-circuit current.

To remedy this, you can either get bigger dimensioned contactors can be used or can in the current path of the individual sections I to IV anywhere, for example in lines 36 to 39 a resistor or a choke is arranged be that for the individual section I in Figure 3 by resistor 43 is shown in line 36. By the resistance or the choke becomes the Short-circuit current limited accordingly for a short time. Furthermore, by a fuse, not shown in Series with the throttle 43 a transformer fire Incorrect switching can be prevented.

In the transformer according to FIG. 4, the primary winding is 12 in the same way from individual sections I to IV constructed like the first part 18 of the control section 17 of the autotransformer according to FIG. 3. Accordingly, in Figure 4 also the same reference numerals for the Switching elements 24 to 31, the lines 32 to 39 and the resistor 43 used. The switching element 11 is in the line 16 arranged which the output of the Individual section IV connects to the neutral conductor N. This transformer is through lines 15 and 16 also switched as an economy transformer.

In the embodiment according to FIG. 5, the Control section 17 of the savings transformer several branches 53, 54, 55 on, which by the switching elements 50, 51, 52, preferably contactors, optionally with neutral line N are connectable.

Claims (7)

1. Lighting installation with gas discharge lamps (6) and an autotransformer for uninterrupted voltage regulation of the gas discharge lamps (6), characterized by at least one switching element (11, 50) in the primary circuit (2; 12) for putting the transformer function out of operation, and at least one further switching element (9, 24 to 31; 51, 52) in the primary circuit (2; 12) or in parallel to the load portion (4; 13) of the transformer, the switching elements (9, 11; 24 to 31, 50, 51, 52) being controlled such that the load portion (4; 13) forms an inductor during a switchover for varying the voltage (U2) on the gas discharge lamps (6).
2. The lighting installation of claim 1, characterized in that the switching elements (9, 11; 24 to 31; 50 to 52) are formed by a contactor.
3. The lighting installation of claim 1 or 2, characterized in that the primary and/or secondary winding (2, 12; 13) of the autotransformer consists at least partly of single portions (I to IV) which are interconnectable in a combination corresponding to the voltage (U2) on the consumer (6).
4. The lighting installation of claim 1 and 3, characterized in that each single portion (I to IV) in the primary circuit (2) has two further switching elements (24 to 31), the first switching element (24 to 27) being provided in the current path of the single portion (I to IV) and the second switching element (28 to 31) between the input (E) and the output (A) of the single portion (I to IV).
5. The lighting installation of one of the above claims, characerized in that each single portion (I to IV) has a resistor, an inductor (43) and/or a fuse.
6. The lighting installation of one of the above claims characterized in that the transformer winding of the autotransformer has a load portion (4) connected on the input side to the phase (L) of the network and on the output side to the phase of the gas discharge lamps (6), and a control portion (17) connected on the output side with the neutral conductor (N) and consisting at least partly of the single portions (I to IV) which are connectable with the neutral conductor (N) in a combination corresponding to the voltage (U2) on the gas discharge lamps (6).
7. The lighting installation of claim 6, characterized in that the control portion (17) consists of a first part (18) and a second part (19) between the first part (18) and the load portion (4), the number of turns of the second part (19) connected with the neutral conductor (N) being invariable and the number of turns of the first part (18) connected with the neutral conductor (N) being variable.

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