Excitor

Abstract

The invention discloses an excitor. The excitor at least comprises a piston, an iron core, an elastic element, a magnetic coil, a clamping piece and an iron piece. A first elastic element is positioned between the piston and the iron core; in normal state, a support rod of the piston is clamped with the clamping piece, and the clamping piece is fixed to the iron piece to ensure that the first elastic element is in a compression state; and at the time, the piston is tightly fixed by the clamping piece and the iron piece, so the piston cannot easily fall off due to the temperature or external shock. The iron core is made of metal iron and has a preset distance with the iron piece; when current overloads, the magnetic coil generates a magnetic field according to the inputted current, and themagnetic field can make the iron piece move towards the iron core and drive the clamping piece to fall off from the support rod of the piston; and after the clamping piece falls off from the support rod of the piston, the piston is driven by the elastic force generated by the first elastic element to move far away from the iron core so as to trigger a current release to cut off the circuit in an electrical system.

Description

technical field [0001] The invention relates to overcurrent protection technology, in particular to an exciter. Background technique [0002] Low-voltage circuit-breaker (LVCB) is a common component used to realize overcurrent protection of electrical system, and current trip unit (Electronic Trip Unit, ETU) is an important part of LVCB . [0003] An ETU typically includes: current sensors, electronic circuits and actuators. When the current in the electrical system is overloaded, the exciter will trigger the ETU to disconnect a part used to conduct the circuit in the electrical system, thereby disconnecting the circuit in the electrical system, so that the impact of the current overload will not spread to the electrical system All the components in the system realize the protection of the electrical equipment in the electrical system. [0004] Existing exciters generally include: permanent magnets, pistons, elastic elements, and electromagnet components composed of iron ...

AI Technical Summary

Problems solved by technology

[0008] 1. The temperature of the environment where the magnetic material is located has a certain influence on its magnetism. Therefore, the temperature of the environment where the actuator is located may invalidate the positive magnetic field. Therefore, under normal conditions, the positive magnetic field between the piston and the iron core The force may be less than the elastic force produced by the elastic element, so that the actuator may trigger the ETU to disconnect the circuit in the electrical system under normal conditions

[0009] 2. Although under normal conditions, the piston is fastened to the iron core by the force of the positive magnetic field, when the ETU is vibrated, it may still cause the piston to separate from the iron core, and be driven by the elastic force generated by the elastic element Move away from the iron core, so that the exciter will also trigger the ETU to disconnect the circuit in the electrical system under normal conditions

[0010] It can be seen that under normal conditions, the piston is fastened by the force of the magnetic field, and the force of the magnetic field cannot guarantee the stability of the fastening. Therefore, the existing actuator may also trigger the ETU to disconnect the electrical system under normal conditions. in the circuit, so that the reliability of overcurrent protection is not high

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