SE451935B - Street lighting voltage regulator - Google Patents

Abstract

The voltage regulator is for lighting mains, in which between the feed mains phase line and the zero line an economy transformer (1) is connected. Effect feed to the lighting mains occurs through the intermediary of this transformer. Parallel to the transformer secondary winding (3) is a first coupling (k1) with which the secondary winding (3) can be short-circuited. The outer end of the secondary winding (3) is connected to the zero line with a second coupling (k2), and the the phase line with a throttle (4). The function of the couplings is so controlled that in the unregulated condition the first coupling (k1) is fixed and the second (k2) is open. When feed regulation commences the first coupling opens, and after a specific delay the second coupling closes. (Provisional Basic advised week 8433)

Description

a .. -__ 451 935 fl .M for the lights to go out. To eliminate this, adjustable saving transformers have also been proposed for use, where a mechanical sliding contact can be moved along the windings of the Q transformer. The disadvantage here is that the mechanical sliding contact wears, which results in unreliability and a high price. In addition, the winding wire in such a saving transformer should be dimensioned in its entirety to the same thickness according to the maximum current, which __ substantially increases the price of the transformer. The invention aims to provide an improved regulator based on an energy-saving transformer, which can be realized with a structurally simple and inexpensive transformer and with which a step-by-step regulation is achieved in such a way that the intermediate stage prevents the lamps from going out.

This object is achieved with a regulator, which is characterized in the manner stated in the appended patent claim.

The following exemplary embodiments according to the invention are described with reference to the accompanying drawing, which shows a controller connection according to the invention as a phase application. It is obvious that in the case of multi-phase applications, the corresponding connection is realized between the respective phase line and neutral line.

The phase line voltage is e.g. 230 V. A saving transformer 1 has been connected between the phase line and the neutral line, in which there is a two-part winding, the primary winding of which is windings 2 and 3 and the secondary winding of which is winding 3. The lamp load has been connected between the intermediate terminals 2 and 3 and the neutral line. In parallel with the secondary winding 3 there is a connection k1, with which the secondary winding 3 can be short-circuited.

The outer end of the secondary winding 3 has on one side been connected with a connection kz to the neutral line and on the other hand with a choke 4 to the phase line. The winding 2 3 451 955 has relatively few turns and consists of a thick winding tree dimensioned for the main current. The secondary winding 3 has a relatively large number of turns and consists of a thin winding tree, since via the current they become considerably small in relation to the main current.

The function of the controller is as follows. In the unregulated state, when a substantially non-decreasing mains voltage is desired for the lamp load, the connection k1 is fixed and the connection kz is open. In this case, the saving transformer functions in the same way as a current transformer, the secondary winding 3 of which is not loaded, but where a current which can flow in correspondence to the rotational ratio of the windings 2 and 3 is smaller than the main current flowing via the lamp load. In this case, the primary winding 2 of the (current transformer) does not function as a choke for the main current, and in the winding 2 no appreciable reduction of the voltage takes place either.

The mat regulation is started by opening the coupling k1. The choke 4 now connects to the circuit and its impedance is reflected in the transformer 2 winding, which acts as a choke. The voltage of the lamp load decreases from 230 V to, for example, 215 V. After a certain time, which is long enough for the condition of the lamps to stabilize, the coupling 2 closes, whereby the function of the saving transformer 1 changes to the function of an ordinary saving transformer. Only a small current now flows through the choke 4, whereby the inductive reactive power caused by this is nevertheless vanishingly small compared with the power saving which can be achieved with a saving transformer connection. In the case of the saving transformer connection, the voltage of the lamp load is e.g. 250 V. The energy saving achieved is about 20%.

It can be noted that the connections k1 and kz can be realized with cheap connections with low current _ .fl- aqø-.w-æ .. 451 935 '4 I' This together with a secondary winding 3 with thin wire enables the construction of a regulator to such small costs that the regulator's repayment period through the above-mentioned energy savings becomes extremely short.

When realized in practice, several sockets can be arranged at the outer end of the secondary winding 3, to which the coupling k1 and the choke 4 can be selectively connected. The choke 4 can also be made adjustable for regulating the intermediate voltage.

E38

Claims (1)

1. B 451 935 E-ë -: _ §_n _: _ k _: _ a_! Voltage regulator for lighting nets, in particular a street lighting regulator, to which belongs a saving transformer (1) connected between the phase line of the supply network and the neutral line, through which transmission power supply to the lighting net takes place, characterized in that in parallel with the saving transformer 3 a first connection (k1) has been arranged, with which the secondary coil (3) can be short-circuited, and that the outer end of the secondary coil (3) has been connected to the neutral line with a second connection (ka) and to the phase line with a choke ( 4), and the function of the couplings is arranged to be controlled in such a way that in the unregulated state the first coupling (k1) is fixed and the second coupling (k2) is open and that when mat regulation begins, the first coupling (k1) opens and after a certain time of delay the second clutch (kz) closes.