DE1156880B - Device for controlling a medium level equality for regulating transformers - Google Patents

Description

Device for controlling a medium level equality for Regulating transformers When regulating transformers are operated in parallel, one of the Transformers are usually assigned a leading role, and all other regulating transformers are controlled depending on this one. With such a parallel operation it depends on the fact that when regulating up or down, all connected in parallel Transformers always have the same number of stages.

It is also known to operate the control device in parallel so to design that when moving apart the transformers as a result of a previously initiated regulation an immediate termination of the control process or a shutdown the stuck transformers or the entire system.

In contrast to parallel operation, it is when one or several regulating transformers to one or more already in operation necessary not to switch on at the same level to avoid voltage jumps, but rather to ensure that the same voltage is present on both sides.

It is known that loaded transformers experience a voltage drop at the internal resistance, with which the to be switched on for adjustment to the mains voltage must be switched in their number of stages so that they are opposite to the open-circuit voltage the burdened by the voltage drop across the internal resistance of the latter in their Number of stages are reduced. After that, it becomes necessary to run the operational load without large voltage increase to distribute evenly on all tap changers what up to now it has been done in the way that the stepped switchgears switched on by hand from higher and the tap changers already in operation by hand from lower were controlled until everyone was at an intermediate level.

The invention provides an improvement on the known by the Control for the intermediate level takes place fully automatically. This is according to the invention achieved in that a device for controlling a mean level equality of regulating transformers running in parallel is provided for at the moment the connection of transformers to those already in operation when unequal Output stage of the step switchgear involved in the control, the synchronism is directed to an intermediate level between these output levels, such that the tap changers involved in the control process alternate with the clock-generating become, whereby automatically all lower ones are one step higher and all higher to be controlled one step lower and taking after each step the tap changer one, which stands still for a moment when the command is given Step switchgear transfers its clocking function to the next, which also moves, with which it is controlled alternately until all tap changers are set to the same intermediate level.

The alternating contact is made in a certain order by toggle relays caused by which, for the next step, always one of the tap changers the clock is made, namely the one that controls the control commands in the step that has just taken place received and carried out. The sequence is determined by the starting position of the toggle relay determines which by mutually interlocked auxiliary contacts of circuit breakers which belong to the tap changers.

In the following, the invention will be explained in more detail using a drawing example. In FIG. 1 a, d 1 and d 2 denote the relays which give the raise or lower command or the raise or lower message and are both energized when the regulating transformers have the same level. 5 is an AC power source that provides the actuation voltage for relays d1 and d2. 3 and 4 are circuit breaker auxiliary contacts, which are assigned to the respective circuit breakers of the tap changers I and 11 , and 11 and 12 are contacts of a running relay, which is made to respond during a control process, respectively. 6 is the contact of a toggle relay d6, which at the beginning of the sterile treatment has the position that corresponds to the tap changer in operation. The contact of a relay d9 is denoted by 9, which is excited by the switch-on pulse of a tap changer to be switched on and remains excited until an initiated control process has ended.

Fig. 1b contains contacts of the same type as previously described and in addition the contacts 7 and 8, which are briefly actuated when a circuit breaker is inserted. A resistor 10 is used to short-circuit the relay d 9 via the auxiliary contacts of the relays d 1 and d2 of the drives operating in parallel after the end of the control process, thereby causing it to drop.

I and 11 denote the tap changers operating in parallel with the respective contact tracks 15 and 16. The mode of operation of the automatic is now described as follows. It is assumed that the circuit breaker belonging to I is switched on and tap changer II is to be switched on. In accordance with this process, all contacts 3 are switched and the toggle relay d6 is in position (1). If the circuit breaker belonging to II is inserted, then contact 8 briefly closes when it is triggered and thus causes relay d9 to respond, which is maintained via its contact 9. After the circuit breaker has been switched on, contacts 4 have also moved. As a result, the alternating current source 5 excites via the contact track 15 of the tap changer I and via a synchronization device the corresponding direction relay of the tap changer II, which gives the corresponding control command higher or lower to its drive. As soon as the drive has started to run, the contacts 12 are actuated and thus the toggle relay d 6 is brought into position (I1). When the control step has expired and the contacts 12 have returned to their original position, the contact track 16 is connected to the voltage of the alternating current source 5. As a result, the tap changer I is now queried as to which level it is relative to tap changer 1I. If it is at a higher level, its motor drive receives a lower command, which when carried out causes the toggle relay to be thrown around again and thus the contact track 15 is connected to voltage. This change continues until the two step switchgears meet on a middle level, the relays 1 and 2 then respond in both switchgear, whereby the relay d9 is short-circuited via resistor 10 and caused to drop. This completes the process of controlling to a medium level.

The facility can be expanded to any number at any time Tap changers. Here it is necessary to use a toggle relay by means of a step circuit to replace, in turn, all the tap changers involved alternate with the clock makes, with the clock giving the others all a step in the direction of its own Tap position controls, but then the management to the next involved tap changer passes on, which does the same.

The control will be explained using an example. Four step switchgears are to be controlled at the middle level, whereby it is assumed that the step switchgears are initially on the following levels: Step switchgear I ................. Level 11 step switchgear II .... ............ Level 12 step control unit III ............... Level 3 step control unit IV ............... Step 2 If it is assumed that the step controller I is the first to set the clock, then the following processes take place: Clocking Step switching stage of those involved steps for the step switchgear next Control step II Il I In I IV 0 1 11 I 12 I 3 2 1 I1 11 11 4 I 3 2 III 11 11 5 4 3 IV 10 10 5 5 4 I 9 9 5 5 S Il 9 9! 6 6 6 III 9 9 7 7 7 IV 9 8 7 7 8 (1) 7 I 7 7 j 7 After the eighth control step, I becomes the clock generator, but can no longer issue a control command because synchronization has been established. As a result, a relay corresponding to relay 9 in FIG. 1 b is brought to drop out (or to respond in another circuit), which relay reports the control process as finished and can cause further automatics to be switched off or on.

Claims (3)

PATENT CLAIMS: 1. Device for controlling an average level equality of regulating transformers running in parallel at the moment of connection from transformers to those already in operation with unequal output levels of the step switchgear involved in the control the synchronization to an intermediate middle stage located at these output stages is controlled, characterized in that that the tap changers involved in the control process alternate with the clock-generating become, whereby automatically all lower ones are one step higher and all higher to be controlled one step lower and taking after each step the tap changer one, which stands still for a moment when the command is given Step switchgear transfers its clocking function to the next, which also moves, with which it is controlled alternately until all tap changers are set to the same intermediate level. 2. Device according to claim 1, characterized characterized in that the alternation of making contact in a certain order Toggle relay is triggered, which is always one automatically for the next step make the step switchgears the clock, the control commands in the step that has just been carried out have received and performed, the order being determined by the initial position of the Toggle relay is determined via mutually interlocked auxiliary contacts of the to the circuit breaker belonging to the tap changer is specified. 3. Establishment according to claims 1 and 2, characterized in that a relay is provided is, which is only excited by the switch-on pulse of a tap changer to be switched on is and remains excited until the control process initiated thereby all Step switchgear has brought it to an intermediate level. Considered publications: German Patent Nos. 187 395, 593 209, 604 592, 643 920, 657 710, 705 423, 730166; Siemens magazine (1956), p. 105.