Method and device for adhesion detection of main contact of alternating-current contactor

Abstract

The invention relates to a method and a device for adhesion detection of a main contact of an alternating-current contactor to solve the problem that the main contact fails to disconnect in abnormality of the contactor. The device comprises an alternating-current contactor major loop, an alternating-current contactor control loop, an adhesion signal detection circuit and a master controller control circuit. The adhesion detection circuit takes signals from the lower end of the alternating-current contactor, an intermediate relay of the contactor control loop and an alternating-current contactor auxiliary contact. The adhesion detection circuit adopts passive output for outputting signals in an open-collector output mode, and the master controller control circuit takes a PLC (programmable logic controller) or MCU (micro controller unit) as the core and is capable of driving the intermediate relay to realize control of the alternating-current contactor and a forestage power source thereof. The device has the advantages of simple structure and stability and reliability in operation, various operating states of the alternating-current contactor can be detected in real time, fault signals are given out immediately once adhesion occurs, and the forestage power source is disconnected through the master controller to guarantee safety of field personnel and property.

Description

technical field [0001] The invention relates to a main contact adhesion detection device and a detection method of an AC contactor designed to solve the problem that the main contact cannot be broken when the contactor is abnormal. Background technique [0002] AC contactors are common actuators in power equipment and power distribution systems. They are suitable for remote control in power distribution systems, and can frequently break / connect main circuits and large-capacity control circuits. Mainly used in motor control, electric heating equipment, capacitor banks, etc. [0003] In some power supply systems with high power and often working in overload state, when the contactor is seriously overloaded or the equipment is short-circuited, due to the very large current, the heat generated by the main contact of the contactor will be very serious, and the resulting high temperature will make the contactor The contacts of the device are stuck together. In this case, even if...

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