Under-voltage protection device and protection method for circuit breaker

Abstract

The invention discloses an under-voltage protection device and an under-voltage protection method for a circuit breaker. The device comprises an electromagnet connected with an under-voltage protection tripping device of the circuit breaker, and is characterized in that: an under-voltage module is arranged in the under-voltage protection device; and the input end of the under-voltage module is connected with a three-phase power supply, and the output end of the under-voltage module is connected with the electromagnet. Compared with the prior art, the structure and the method realize under-voltage protection over the circuit breaker by the electromagnet under the drive of the under-voltage module, and have the advantages that: (1) an under-voltage value is adjustable within the range of 35 to 85 percent and highly accurate, and has the range of 1V; (2) an under-voltage time delay is continuously adjustable within the range of 0 to 10s and highly accurate, and has the range of 0.5s, and when the time delay is set to be 0s, the under-voltage protection tripping device is an instantaneous under-voltage tripping device; (3) the voltage of three phases can be detected and displayed with the display accuracy of + / -5 percent at the same time to realize minimum phase under-voltage protection; and (4) the electromagnet is electrically neutral when the circuit breaker normally works, so the service life of the electromagnet can be effectively prolonged.

Description

Technical field [0001] The invention relates to a circuit breaker on a power system, in particular to a circuit breaker undervoltage protection device and a protection method thereof. technical background [0002] At present, most of the under-voltage protection functions of circuit breakers on the market use electromagnet under-voltage releases to achieve under-voltage protection. The disadvantages of existing under-voltage releases are: (1) Only one or two Phase undervoltage plays a protective role, and three-phase undervoltage protection cannot be realized at the same time. (2) The undervoltage value is not adjustable, or it is adjusted by a dial switch or a potentiometer, but the accuracy is low and digital setting cannot be realized. (3) When the undervoltage release is working in a higher voltage situation, it is easy to burn, which affects the normal use of the circuit breaker. (4) The existing undervoltage releases work continuously when the circuit breaker is working, ...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is to provide a circuit breaker undervoltage protection device and its protection method in view of the deficiencies in the prior art, which solves the problem that the voltage value of the existing circuit breaker undervoltage release cannot be adjusted or the accuracy is not accurate. High and unable to achieve three-phase simultaneous protection and other issues

Images