TRANSFORMER TESTING FACILITY Russian patent published in 2019 - IPC G01R31/00 H02M5/00 

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering and is used in transformer plants. With circuit breaker 1 switched on, industrial circuit voltage is converted into adjustable three-phase or three in-phase voltages in known manner in unit 2, which are transmitted via transformers 3–5 to load via switch 6–11. Such phase-shift switch connects output windings of transformers in parallel in single-phase mode (outputs B1, A1) and in three-phase circuit (outputs A1, B1, C1) – in three-phase mode. Any position of the switch is set by electric motor 14 via gear 14. Operation of engine 14 in one direction or another is provided by contactors 15, 16 connected by coils 17, 18 by commands of contacts 22, 23. Electric motor rotates to the specified side until the contact of limit switch 19 or 20 fixing contacts position 6–11 is opened. Simultaneously, the limit switch supplies current to the trigger relay winding 21, which stores the last movement direction (state) of the switch. After disconnection from circuit breaker 1 its block-contact 24 includes relay 25 of time, which electronic or mechanical (roll-over contact) method closes contact 26 for several tens of seconds, and then disconnects. At this time coil 17 or 18 of the respective contactor is switched on and the electric motor withdraw contacts 6–11 into the intermediate (third) state, when they are all open, in such condition two phases (B, C) are cut off from the output.

EFFECT: technical result consists in improvement of reliability.

1 cl, 2 dwg