Comprehensive once current-limiting and voltage-limiting resonance eliminator

Abstract

The invention relates to a comprehensive once current-limiting and voltage-limiting resonance eliminator which is used for eliminating ferroresonance caused by an electromagnetic transformer in 6-35kv neutral ungrounding alternating-current power system. The comprehensive once current-limiting and voltage-limiting resonance eliminator comprises a base, a lower electrode, an upper electrode and an insulation sleeve. A nonlinear current-limiting and voltage-limiting component is arranged in an inner cavity of the insulation sleeve and composed of a PTC (pitch trim compensator) and a VDR (voltage dependent resistor). Quartz sand is arranged between the nonlinear current-limiting and voltage-limiting component as a filling heat radiation layer, and a current sensor is arranged in the base. The comprehensive once current-limiting and voltage-limiting resonance eliminator can effectively suppress resonance overvoltage of various frequencies and overcurrent of the voltage transformer and avoid burning of the voltage transformer and a high-voltage fuse, is high in heat radiation speed and thermal capacity, and meets the protection requirements for long lines and high load. By the aid of a full-sealing structure, the comprehensive once current-limiting and voltage-limiting resonance eliminator is stable in performance, convenient to monitor, and wider in application range.

Description

[0001] technical field [0002] The invention relates to a primary current-limiting and voltage-limiting comprehensive resonance eliminator, which is used for eliminating ferromagnetic resonance caused by electromagnetic voltage transformers in a 6-35kV neutral point ungrounded power grid, and can protect it from overvoltage or overcurrent damage caused. [0003] Background technique [0004] In the operation of 6-35KV neutral point ungrounded power system, due to various reasons, resonance overvoltage will occur, such as parameter resonance overvoltage, ferromagnetic resonance overvoltage, linear resonance overvoltage and other resonance overvoltages, these The amplitude of the resonant overvoltage can reach more than twice the rated voltage, causing the insulation of electrical equipment in the power grid to age or be damaged and broken down, or even explode; after the electromagnetic saturation of the transformer, a huge overcurrent will be generated, and its value will ...

AI Technical Summary

Problems solved by technology

However, they all have the disadvantages of small nonlinear coefficient, unsatisfactory voltage limiting and current limiting, and poor heat dissipation, and the phenomenon of high-voltage fuse burning still occurs from time to time.

At present, a kind of resonance eliminator composed of zinc oxide nonlinear resistors with high potential gradient is also produced in China. The nonlinear coefficient of this structure is still relatively small, and due to the high potential gradient, the energy capacity is small, such as If it takes a long time, it will be damaged or even explode. It has its own safety problems, its service life is short, and it cannot monitor the flow rate in real time.

Images