Overvoltage fully-guarding technology for neutral point ungrounded system power grid

Abstract

An overvoltage fully-guarding technology for a neutral point ungrounded system power grid is characterized in that three sets of high-voltage ZnO nonlinear resistors 3, 6 and 9 are in parallel connection with series connection branches of three sets of high-energy SiC and high-energy ZnO nonlinear resistors 1, 2, 4, 5, 7 and 8 respectively to form star-shaped connection, and a neutral point is formed. Components with branches being in parallel connection are connected between the neutral point and the ground a SiC nonlinear resistor 14, a high-voltage ZnO nonlinear resistor 13 and high-energy SiC and high-energy ZnO nonlinear resistors 11 and 12 to be used for overvoltage fully-guarding of a power system and power equipment. According to an overvoltage fully-guarding device made by the technology, overvoltage guarding equipment such as an RC resistance-capacitance absorption device, an arc suppression coil, a resonance eliminator and a lightning arrester can be effectively replaced, and the capacity of inside overvoltage and outside overvoltage fully guarding is achieved. The overvoltage fully-guarding device effectively lowers the safety guarding cost of electrical equipment, and has high using value.

Description

technical field [0001] The patent of the invention is a full protection technology applied to the power grid of the neutral point ungrounded system to suppress internal overvoltage and external overvoltage. Background technique [0002] At present, in the central point ungrounded system power grid, for internal overvoltages such as single-phase intermittent arcing grounding overvoltages, resonance overvoltages, operating overvoltages, and external overvoltages such as lightning strikes, the overvoltage protection products mainly include arc suppression coils , Harmonic elimination resistors, resistance-capacitance absorption devices, metal oxide arresters, etc. Such protection products have single protection function and lack of capacitive components to absorb internal overvoltage energy, especially metal oxide arresters, because of the characteristics of non-linear resistors used, they can only provide limited protection for instantaneous overvoltage, and In order to avoid...

AI Technical Summary

Problems solved by technology

Such protection products have single protection function and lack of capacity components to absorb internal overvoltage energy, especially metal oxide arresters, because of the characteristics of non-linear resistors used, they can only provide limited protection for instantaneous overvoltage, and In order to avoid transient overvoltage, its threshold voltage is generally set higher, causing weak insulation equipment to be damaged

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