SU599326A1 - Device for switching power transistor taps - Google Patents

Description

one

The invention relates to electrical engineering and can be used in dd devices for regulating the voltage of power transfmator under load.

Switching devices are known in which thyristors | l, 2 are used to select the tapes of the adjusting windings of a transformer. These devices do not provide emergency operation.

The closest to the present invention is a device whose control system is designed to provide, in the event of a short circuit, a switch to a reinforced emergency tristor unit with a higher rated current compared to the rated current of the working thyristor unit h. The circuit of this switching device assumes the execution of an amplified thyristor emergency mode unit in such a way that it contains only .two, connected anti-parallel to the thyristor. Such an embodiment of the thyristor unit does not ensure reliable switching of the device in emergency situations, to the amplified thyristor unit.

It is required to include in the block the number of thyristors more than four.

The aim of the invention is to increase the reliability of the device.

This is achieved by the fact that a device for switching branches of a power transformer, comprising thyristor branches for switching branches, a control system for thyristor blocks, an emergency mode thyristor unit and a short-circuit current sensor, is additionally equipped with a driver for controlling pulses, a high linear resistance, for example, a varistor, and the driver for ps dc switch; parallel emergency unit, and the control system power circuit is connected to Turning to the secondary winding of the transformer syutovogo.

The drawing shows a device diagram for switching the transformer branches.

Claims (3)

The device contains thyristor blocks 1, 2, switching branches 3, is wrapped with high voltage, enhanced thyristor block 5 of emergency mode, containing any number of thyristors connected in opposite-parallel, control system 6, sending a control signal to one of thyristor blocks 1, 2, 5 , sensor 7 short circuit current. To the amplified thyristor emergency mode unit, in parallel, through varistor 8, a shaper 9 of control pulses is connected for amplified bpoka. emergency mode. The control system 6 is powered by a switching device. It is carried out from the secondary winding 10 of a low voltage adjustable transformer. Control pulse shaper 9 can be made in the form of a square pulse generator. During normal operation of the device, the control system 6 issues signals to one of the tariff mountain blocks 1, 2, 5, including it in operation. Shaped gel 9 does not work, the hook like voltage of the volt-ampere characteristic of varistor 8 is somewhat higher, the maximum operating voltage of the thyristor unit 5, and, therefore, no power is supplied to the driver 9. When a short circuit occurs, the sensor 7 sends a signal to the control system 6. The control system 6 stops the supply of control pulses, the operating unit is closed, the circuit for the current is interrupted and the network voltage is restored on the thyristor blocks. As soon as the voltage on the emergency mode unit reaches a value exceeding the bending voltage of the current-voltage characteristic of the varistor 8, the latter begins to pass a current, the driver shunts 9. The driver generates the control signal to the unit 5, the unit is unlocked, passing through itself. The remaining blocks are set to a voltage not exceeding the working ones. After unlocking the reinforced block 5, the driver 9 loses power. The process is repeated for each half-wave until the short circuit is terminated and the main control system 6 comes into operation. Descriptions) A new order of work also takes place when the supply of the control system 6 by the control system 6 is interrupted due to a malfunction in it. The circuit diagram allows it to be used in another case where the transformer is intended for dead-end installation. With the inclusion of such a transformer in the network, for the first time the control system; 6, the switching device does not work, since it still does not receive power from the secondary winding 1O of the low voltage, in this case, the shaper 9 is activated according to the same procedure described above, in the absence of signals from the control system. When a voltage appears on the secondary side of the transformer, the control system 6 receives power, after which the driver 9 is automatically turned off. The proposed scheme ensures the reliability of the device in emergency situations. Claims An apparatus for switching branches of a power transformer, comprising thyristor switching units of branches, a thyristor control system, an emergency mode thyristor unit and a short-circuit current sensor, in order to improve reliability it is additionally equipped with a control pulse driver, a high linear resistance, for example, a varistor, with the driver via resistance; connected in parallel with the emergency mode thyristor unit, and the control system power supply circuit is connected to the terminals for connection to the secondary winding of the power transformer. Sources of information taken into account in the examination: 1.Patent of England N ° 1037.414, 2 H 01 F 21/12, 1969. 2. Japanese Patent No. 43852/71, 2 H 01F 1971, 3. Japanese Patent No. 19450/71, 2 H O1 f, Jt 05 F 1971.