Double coil variable current control circuit of vacuum circuit breaker permanent magnet mechanism

Abstract

The invention provides a double coil variable current control circuit for vacuum circuit breaker permanent magnet mechanism; in the closing process, an opening coil is negatively electrified, which partially neutralizes the permanent magnet holding force, reduces the closing motion current, simultaneously regulates the current in the closing coil and lowers the kinetic energy and the impact speed of the iron core on the premise of ensuring the closing speed; in the opening process, the opening coil is positively electrified, the closing coil is negatively electrified or the opening coil is positively electrified, the closing coil is positively electrified; the voltages and currents in the opening coil and the closing coil are sampled by the coil current measuring module, and the collected data are fed back to a central control module which can calculate the current change rates of the present coils and regulate the current value in the opening coil based on the result; by feeding back samplings of the voltages and currents in the opening coil and the closing coil of the permanent magnet mechanism, the invention can regulate the current amplitude in coils and makes a reasonable fit between the operating characteristics of the permanent magnet mechanism and the counterforce characteristics of the circuit breaker.

Description

technical field [0001] The invention belongs to the field of electronic applications, and in particular relates to a double-coil variable current control circuit of a permanent magnet mechanism of a vacuum circuit breaker. Background technique [0002] The bistable permanent magnet mechanism is a new type of operating mechanism designed for vacuum circuit breakers. It has attracted widespread attention because of its high reliability and small dispersion of opening and closing times, and it has been widely used in the medium-voltage field. Its main action features are: when the opening or closing signal is sent out, the power supply supplies power to the opening coil or closing coil, and the electromagnetic force generated by the coil overcomes the reaction force and permanent magnetic holding force, drives the iron core and then drives the circuit breaker contacts Complete opening and closing operations. After the action is completed, the permanent magnet provides the hold...

AI Technical Summary

Problems solved by technology

High-voltage circuit breakers require faster action speeds. Under the condition of a certain number of ampere-turns, in order to properly reduce the current, the number of turns can only be increased. The more turns of the coil, the greater the inductance, and the current rises to the action requirement. The longer the current time, the longer the action time will be, which will increase the dispersion of opening and closing time, and cannot meet the requirements of synchronous closing

[0005] The existing mechanism design generally focuses on the rationality of the structure, so that the characteristics of the permanent magnet mechanism can be well matched with the characteristics of the vacuum circuit breaker. The defect of insufficient sub-speed

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