Switching lockout limiter to prevent overloading of power plant start-up backup transformers

Abstract

The invention discloses a switching locking limiter for preventing an overload of a starting spare transformer of a power plant. The switching locking limiter comprises two generator sets, two plant high-voltage transformers, a starting spare transformer, eight current transducers, a judgment control system and four plant power fast switching devices; each plant working power branch and each spare power branch of the two generator sets are respectively provided with the current transducers; the current transducers transmit collected real-time plant working branch current data and spare branch current data to the judgment control system; and the judgment control system controls switching outlet opening or outlet locking of the plant power fast switching devices and selectively switches a power section of the plant high-voltage transformers to the starting spare transformer. Two generator plant power supplies respectively retain one branch and are respectively loaded by the two branches of the starting spare transformer, so the two generator sets are guaranteed to be shut down safely, the condition that one generator set loses the power is prevented from occurring, and the overload operation of the starting spare transformer does not cause.

Description

technical field [0001] The invention relates to an electrical automatic control method and equipment for a thermal power plant, in particular to a switching lock limiter for preventing overload of a power plant start-up backup transformer. Background technique [0002] Now power plants generally use a start-up backup transformer shared by two generating sets as the unit’s backup power supply, and the factory power fast switching device is used to realize the mutual switching between the generator set’s factory high-voltage transformer and the start-up backup transformer, based on the construction cost Considering that the capacity of the general start-up backup transformer is basically the same as that of a factory high-voltage transformer for a generator set, there is a problem that when two generator sets trip at the same time, the factory power fast switching device will switch the factory high voltage of the two generator sets The transformers are all switched to the sta...

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Problems solved by technology

[0002] Now power plants generally use a start-up backup transformer shared by two generating sets as the unit’s backup power supply, and the factory power fast switching device is used to realize the mutual switching between the generator set’s factory high-voltage transformer and the start-up backup transformer, based on the construction cost Considering that the capacity of the general start-up backup transformer is basically the same as that of a factory high-voltage transformer for a generator set, there is a problem that when two generator sets trip at the same time, the factory power fast switching device will switch the factory high voltage of the two generator sets The transformers are all switched to the start-up backup transformer for power supply, which may cause the start-up backup transformer to be damaged due to overload operation. If the switch of the factory power supply is artificially controlled by relying on the outlet pressure plate of the quick switch device for switching on and off the factory power supply, it may cause a single unit to fail. A certain section of the power supply branch of the tripping unit may lose power for the whole section due to the failure of the pressure plate, and the recovery operation after power failure is cumbersome and time-consuming. Damaged safety hazards and poor reliability of equipment operation