SU366463A1 - DEVICE FOR STABILIZATION VOLTAGE THREE-PHASE AC CURRENT - Google Patents

Description

one

A device for stabilizing a three-phase AC voltage for supplying distribution networks of considerable length with a variable load, comparable in power to a power source, containing a three-phase power transformer, the secondary winding of which consists of two parts, a thyristor short circuit connected to the midpoint of the secondary windings, is known. controllable saturation choke connected in series with the secondary winding of a power transformer, current transformers connected in the circuit Rossel and saturation in the circuit of the power transformer output winding and the control and protection units.

In order to increase reliability and speed, the proposed device additionally applied a block of throttle current versus load current, the inputs of which are connected to current transformers in saturation drosel circuits with a rotating magnetic field and current transformers in the main winding of a power transformer through a control unit, and the output through The driver of the trigger pulses is connected to the control electrodes of the short-circuit thyristors.

The drawing shows a circuit diagram of the device described.

It consists of a power transformer / with a primary winding 2 and a secondary winding consisting of two parts: main 3 and booster 4. In series with the secondary winding, a controllable saturation inductor 5 with a rotating magnetic field is connected.

To the midpoint of the secondary winding of the subplug thyristor short circuit 6, controlled by block 7 through block 8 of protection and shaper 9 trigger pulses. The control unit 7 is connected to the secondary windings of current transformers 10 connected in the output winding circuits of the power transformer /. The device has a block 11 comparing the throttle current with the load current, the inputs of which are connected to block 7 and current transformers 12 in the saturation throttle circuit 5, and the output to the driver 9 trigger pulses.

The winding 13 throttle 5 is connected through a magnetic amplifier 14 to block 7.

In idle mode and rated load, the thyristor short-cut 6 is open and the output voltage is equal to that of the main winding 5. In this case, the additional booster winding 4 and the controlled choke 5 are short-circuited

circuit, the current in which is limited by the relatively large resistance of the throttles.

With a varying load, when the load current exceeds the rated current of the device, the thyristor short circuit 6 closes and the output voltage rises by the amount that is yush, the difference between the emf booster winding 4 and a voltage drop in the windings of the choke 5.

The voltage drop across the windings of the chokes 5 is controlled by the current of the control winding 13, which is changed by the magnetic amplifier J4 depending on the magnitude of the load current through the current transformers 10 and the control unit 7.

In this way, the automatic regulation of the voltage under load is dried up.

To increase the reliability of operation of electric motors in transient modes, the closure of the thyristor short circuit 6 is possible only with equal throttle currents and loads, since only in this case the current comparison unit 11 will give a signal to close the short circuit 6.

Pd M: e-t of the o-r e te n u

A device for stabilizing the voltage of a three-phase alternating current, comprising its three-phase power transformer, the secondary winding of which consists of two parts, a thyristor short circuit connected to the middle point of the secondary windings, a controlled winding junction connected in series with the secondary winding of the power transformer, transformers current included in the circuits of the throttle switch: in the output winding circuit of the power transformer, control and protection units, characterized in that, in order to increase reliability and speed, it is equipped with a unit for comparing the throttle current with the load current, the inputs of which are connected to current transformers in the saturation droplet circuit with a rotating magnetic field and current transformers in the main winding of the power transformer through the control unit, and the output through the trigger pulse driver is connected to to the thyristor electrodes of the short circuit.