RU1795393C - Device for electrodynamic testing power transformers - Google Patents

Abstract

Usage: relates to electrical engineering and can be used in electrodynamic tests of high voltage power transformers in short circuit mode. SUMMARY OF THE INVENTION: A device for electrodynamic testing of power transformers (T) comprises 1 three-phase (TF) power supply (1), 1 TF protective switch (2), 3 TF short-circuit (3, 4, 5). test T (10) with primary and secondary windings (12, 13, 14 and 7, 8, 10), respectively, 1 additional bypass switch (6) for shunting the short circuit (3, 4, 5), test T (16) s primary and secondary windings (15, 17, 18 and 19, 20. 21), respectively, T voltage (11), 1 control system (23) short-circuit experiments. The device allows to increase the reliability of the control and reduce the current effects on the valves of the short circuit. 1 ill. &

Description

The invention relates to electrical engineering and can be used in electrodynamic testing of high voltage power transformers in short circuit mode.

The aim of the invention is to increase the reliability of control and reduce current effects on test equipment - short-circuit valves.

The drawing shows a diagram of the proposed device.

The device contains a three-phase power supply 1, a three-phase safety switch 2, power valves З, a 4.5-phase short-circuit, a three-phase test transformer 10 with primary and secondary windings 12, 13, 14 and 7, 8, 9, respectively, an additional shunt switch 6, the tested transformer 16 with primary and secondary windings 15, 17, 18, and 19, 20, 21, respectively, control system 23 for short circuit tests, voltage transformer 11.

Moreover, the first terminals of the secondary windings 7, 8, 9 of the test transformer 10 are connected to one phase of the power supply 1 through the protective switch 2 and the valves 3, 4, 5 of the short circuit, and the second terminals of the secondary windings 7, 8, 9 of the test transformer 10 are connected to the terminal the first terminal of the first primary winding 15 of the transformer 16 under test and to one terminal of the additional bypass switch 6, the other terminal of the additional bypass switch 6 is connected through a protective switch 2 to the phase of the source pi Tanya 1. The first leads of the second and third windings 1.18, all leads of the secondary windings 19, 20, 21 and the second leads of the primary windings 15, 17, 18 of the transformer 16 under test, all the leads of the primary windings 12, 13, 14 of the test transformer 10 are grounded.

The device operates as follows.

The protective switch 2 is turned on, thereby applying a voltage to the high-voltage thyristor valves 3, 4, 5 and an additional shunt switch 6 ...

After a time equal to the charge time of the own energy stores of the high-voltage thyristor valves 3, 4, 5, a control pulse from the system

control 23 in a predetermined phase of the supply voltage, an additional shunt switch 6 in the last positive half-cycle of the supply voltage relative to the estimated expected time of switching on the shunt switch 6, then control pulses from the control system 23 are applied to the predetermined phase relative to the transition of the supply voltage through the zero value

high voltage thyristor valves 3, 4, 5.

In this case, the short-circuit current begins to flow through the test transformer 16, then after a time, which is determined by the variation in the time of switching on of the additional bypass switch 6 (determined by its design features), the bypass switch 6 and the bypass valves 3, 4, 5 and test transformer 10.

The transformer under test 16 is considered to have passed electrodynamic tests for resistance to short circuit, if its parameters during the test did not exceed the permissible limits.

Claims (1)

SUMMARY OF THE INVENTION An apparatus for electrodynamic testing of power transformers, comprising a first group of terminals for connecting a single phase of a three-phase power supply via a protective switch, to which the first terminals of the secondary windings of the test transformer are connected via a short circuit, the second terminals of the secondary windings of the test transformer are connected to a terminal for connecting the first terminal of the primary windings of the transformer under test, in which the first terminals of the second and third ne between primary windings, all outputs of the secondary windings and primary windings of the second terminals are earthed, characterized in that, in order to increase the reliability of the control and reduce current effects on short-circuiting valves, it introduced an additional shunt switch, the first terminals of the secondary obmo the current of the test transformer is connected to the second terminals of the secondary windings through three valves of the short circuit of the test transformer, connected by the first group of terminals connected in parallel, all the terminals of the primary parallel which through an additional winding of the test transformer shunt switch connected shorted and grounded.