Microcomputer five-prevention-based circuit for preventing misoperation of bus voltage parallel circuit

Abstract

The invention discloses a microcomputer five-prevention-based bus voltage parallel circuit misoperation prevention loop, and the loop comprises a microcomputer five-prevention lock BS, a selector switch QK, a segmented or buscouple circuit breaker FDL auxiliary contact, an isolation switch 1G auxiliary contact, an isolation switch 2G auxiliary contact and a bus PT parallel relay BLJ; the other endof the microcomputer five-prevention lock BS is electrically connected with one end of the isolation switch 1G auxiliary contact, the other end of the isolation switch 1G auxiliary contact is electrically connected with one end of the section or bus tie circuit breaker FDL auxiliary contact, and the other end of the section or bus tie circuit breaker FDL auxiliary contact is electrically connected with one end of the isolation switch 2G auxiliary contact; The other end of the isolation switch 2G auxiliary contact is electrically connected with one end of the change-over switch QK, and the other end of the change-over switch QK is electrically connected with one end of a coil of the bus PT parallel relay BLJ; and one contact of the bus PT parallel relay BLJ is short-circuited with two endsof the microcomputer five-prevention lock BS.

Description

technical field [0001] The present invention relates to the technical field of power system protection, and more specifically, to a microcomputer-based five-prevention circuit for preventing bus voltage parallel loops from malfunctioning. Background technique [0002] Potential transformer, referred to as PT, is a special transformer used to measure the high voltage of the power grid. It can convert the high voltage into a lower voltage according to the specified ratio, and then connect it to protection, measurement and control, safety devices, instruments, meters and other devices. to collect or measure. For voltage transformers, no matter how many volts the primary side voltage is, the secondary side voltage is generally specified as 57.7 volts or 100 volts to supply the voltage required by the voltage coils of automatic devices such as related meters and relay protection. The primary actual conversion value is reflected by the secondary voltage change of the voltage tran...

AI Technical Summary

Problems solved by technology

[0010]① There is no mandatory locking measure for the parallel start-up circuit of the busbar voltage. Defects, the operation situation that does not conform to the "parallel bus PT or release of normal operation procedures" often occurs, which brings hidden dangers to the safe and stable power supply of the power system;

[0011]②When the secondary circuit of the busbar voltage is in parallel state, there is no mandatory blocking of the tripping circuit of the corresponding bus coupler or segmental interval circuit breaker. When the tripping pressure plate is opened, there is a system fault that first disconnects the primary parallel circuit, and then disconnects the secondary parallel circuit of the bus voltage, and there is a risk of short-circuit current burning the secondary equipment and the circuit

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