Undervoltage tripper and working method thereof

Abstract

The invention relates to an undervoltage tripper, comprising a rectification circuit, an electromagnet coil, am armature, a buck circuit, a relay, a sampling circuit and a main control module, wherein the rectification circuit is connected with an external power grid, and the armature is controlled by the electromagnet coil; the main control module stores a rated voltage Ue and a strong start voltage value and is used for collecting an output voltage and a voltage period of the sampling circuit, so that an effective value and a pulse direct current voltage value of the external power grid are calculated; when the voltage of the external power grid reaches to 80% of the rated voltage Ue, and the pulse direct current voltage reaches to the strong start voltage value, a normally open contact is closed firstly, and a switch circuit is turned on, after the armature is closed, the normally open contact is disconnected; and when the voltage of the external power grid is less than 50% of the rated voltage Ue, the switch circuit is turned off. The tripper is reliable in closing, small in coil heating value, strong in anti-interference capacity, and applicable to frequency conversion occasions like generators.

Description

technical field

[0001] The invention relates to a low-power undervoltage release and its working method. Background technique

[0002] The undervoltage release is one of the important components of circuit breakers, especially frame circuit breakers. The undervoltage release is a release that makes the circuit breaker disconnect with or without delay when its terminal voltage drops to a certain range. When the power supply voltage drops (even slowly) to the rated operating Within the range of 70% to 35% of the voltage, the undervoltage release should act (the coil of the release is de-energized, and the movable armature in the coil is pushed out by the return spring—tripping), and the undervoltage release will trip when the power supply voltage is equal to When the rated operating voltage of the undervoltage release is 35% of the rated operating voltage, the undervoltage release should be able to prevent the circuit breaker from closing; when the power supply voltage is equ...

Images