Pre-ionized multi-gap cermet gas discharge tube overvoltage protection device

Abstract

An overvoltage protection device for a pre-ionized multi-gap metal-ceramic gas discharge tube relates to an overvoltage protection technology for a power supply system. It includes a multi-gap metal-ceramic gas discharge tube and a pulse transformer; the multi-gap metal-ceramic gas discharge tube has a terminal electrode A and a terminal electrode A', and also has n intermediate electrodes; the secondary coil of the pulse transformer includes n sub-coils, n resistors With the parallel combination of capacitors, each sub-coil is connected in series with a parallel combination of resistance and capacitance and is called a coil resistance-capacitance combination, and n coil resistance-capacitance combinations are connected in series; each intermediate electrode corresponds to the coil resistance of the same serial number. The tail end of the capacitor combination is conductively connected; the primary coil of the pulse transformer is connected in series with a parallel combination of a resistor and a capacitor and a switch device. The switching device is used to start the primary circuit of the pulse transformer, and after boosting, it is simultaneously applied to the multi-gap discharge tube through the resistance-capacitance combination of the secondary sub-coil of the pulse transformer, so that all the gaps are broken down at the same time, so as to reduce the limiting voltage and improve the protection level.

Description

technical field [0001] The invention relates to a power supply system overvoltage protection technology, in particular to a pre-ionization multi-gap cermet gas discharge tube overvoltage protection device. Background technique [0002] Multi-gap metal-ceramic gas discharge tube (hereinafter referred to as M-GDT) includes terminal electrode A and terminal electrode A', and also includes n intermediate electrodes K1~Kn, where n≥1, and the two adjacent electrodes of the M-GDT There are three separate gaps in between. Compared with single-gap gas discharge tube (hereinafter referred to as GDT), M-GDT has larger flow capacity, lower residual pressure, no freewheeling, higher reliability and better stability. With M-GDT as the main component, it can form an overvoltage protection unit, and multiple such overvoltage protection units can form a power surge protector (also known as a lightning arrester or surge protector). [0003] A Chinese patent discloses an overvoltage protecti...

AI Technical Summary

Problems solved by technology

Although the pulse breakdown voltage between A-K1 or A'-K1 electrodes is much lower than the pulse breakdown voltage between GDT terminal electrodes, the pulse breakdown voltage between A-K1 or A'-K1 electrodes is due to the varistor The voltage ratio of MOV exists, the limiting voltage is still high, and the protection level is still low

It can be seen that the limit voltage of the overvoltage protection module of the above-mentioned gap metal-ceramic gas discharge tube is still very high, and at the same time, the varistor still has a fire hazard when the thermal separation is unreliable

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