A kind of overvoltage protector with the function of varistor fault monitoring

Abstract

The present invention relates to the technical field of overvoltage protectors, in particular to an overvoltage protector with a varistor fault monitoring function, including a single chip microcomputer I, a detection module, a varistor, a pulse signal acquisition module and a voltage sampling module. The acquisition module is connected to the single-chip microcomputer I and collects the temperature signal of the piezoresistor, and the humidity detection module is connected to the single-chip microcomputer I and collects the humidity signal of the piezoresistor; the pulse signal collection module is used to detect the pulse signal generated by the piezoresistor action ; The single-chip microcomputer I is connected to the single-chip microcomputer II used for piezoresistor fault signal analysis through the communication module; the voltage sampling module is used to collect the voltage signal of the three-phase line. The present invention monitors the aging and moisture-corrosion conditions of the varistor in real time, avoids equipment accident shutdown caused by the damage of the varistor, has high detection accuracy and knows whether the varistor is damaged in time, and improves the use of the overvoltage protector benefit.

Description

technical field [0001] The invention relates to the technical field of overvoltage protectors, in particular to an overvoltage protector with a varistor fault monitoring function. Background technique [0002] The overvoltage protector is a high-performance overvoltage absorbing device, suitable for 35KV and below power systems. It is an advanced protector that limits lightning overvoltage and operating overvoltage. It is mainly used to protect generators, transformers, switches, The insulation of electrical equipment such as bus bars, motors, and parallel compensation capacitor banks is protected from overvoltage damage, and it can effectively protect phase-to-phase and phase-to-ground overvoltages. The existing overvoltage protector is to put the resistor (varistor) into the inside of the insulating tube, there is a cavity between the resistor and the insulating tube, the cavity is filled with air, one end is connected to the circuit A, B, C phase, and the other One end c...

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Problems solved by technology

However, due to the fixed number of discharge times of the piezoresistor, it is often damaged before reaching the limit value of the discharge times. According to this detection method, the detection accuracy fluctuates greatly, the precision is poor, and the phenomenon of serious deviation with temperature, resistance aging, The impact resistance is weakened, the reference voltage drops, and the resistance frequently operates, which is likely to cause repeated voltage on and off. When the temperature difference between the inside and outside is large, moisture or water enters, which accelerates the deterioration of the resistance and causes damage to the internal insulation. The quality of the voltage protector cannot be determined by the accurate detection of the resistance by the counter

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