Anti-voltage-sag and overcurrent protection linkage control device and control method thereof

Abstract

The invention relates to an anti-voltage-sag and overcurrent protection linkage control device and a control method thereof. The device and the method are suitable for performing overcurrent protection on a load side and performing anti-voltage-sag control on a power supply side of power equipment. The device comprises a main power supply module connected to a power supply side, a standby power supply module which is connected with the main power supply module and charges the main power supply module, a CPU module which is connected with the main power supply module, a voltage and current signal acquisition and processing module which is connected with the CPU module, a relay switch and circuit breaker module which is connected with the CPU module, and an FRAM storage module which is connected with the CPU module. The influence of system-side voltage sag on load-side equipment can be effectively prevented; voltage shaking of the power supply side due to the fact that the fault cannot be removed in time when the load side breaks down can be prevented, the safe operation of equipment on the adjacent side cannot be affected, the selectivity and reliability of an existing anti-voltage-sag device can be improved, and the influence of the anti-voltage-sag device on rapid fault element removal of the system is prevented.

Description

technical field [0001] The invention belongs to the technical field of electric power system relay protection, and in particular relates to a protection device suitable for electric power equipment. [0002] The invention provides an anti-shake electricity and overcurrent protection linkage control device for overcurrent protection on the load side and anti-shake electricity control on the power supply side and an anti-shake electricity and overcurrent protection linkage control device and a control method thereof. Background technique [0003] During the operation of the power system, due to lightning strikes, short-circuit fault reclosing, internal and external power grid failures, and large-scale equipment startups, etc., the voltage will fluctuate greatly instantaneously or the power will be restored after a short-term power failure. This phenomenon is usually called " Akira electric". The basic types of swaying electricity generated by the power supply system are: volt...

AI Technical Summary

Problems solved by technology

When the voltage drop exceeds 20%, it is easy to cause the equipment controlled by the AC contactor to trip and stop

[0006] At the same time, the sway phenomenon caused by the power supply side and the power supply line fault seriously affects the stable and safe operation of the load-side equipment. The machine stops and the power is restarted, which endangers the safety and stable operation of the load-side equipment; in order to prevent the fluctuation of the load-side equipment caused by the swaying electricity, the control circuit breaker on the load side is used to delay the disconnection, although it can prevent the power-side swaying electricity. The circuit breaker is disconnected, but it implies that it cannot be cut off in time due to the short-circuit fault on the load side and the equipment over-current accident, which expands the accident caused by the fault on the load side.

[0007] Chinese Patent Publication No. CN 109474206 A discloses a "Intelligent restart device and method for beam pumping unit configured with power frequency direct start after swaying power", which can accurately identify the forward and reverse process of the motor after it is disconnected from the grid. Switch on when shutting down or when swinging in the forward direction, and the starting current is small. In view of the fact that the stop position, swing direction, and swing time of the crank balance weight of the beam pumping unit are different when the shaking occurs, analyze various data and intelligently restart , and also has thermal overload protection, rotor blocking protection, zero-sequence overcurrent protection, etc., but there are still limitations and cannot be widely used in power equipment. Improve the anti-shake ability of the power supply side and the overcurrent protection ability of the equipment load side

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