Fuse protection device and method applied to electromagnetic voltage transformer

Abstract

The invention discloses a fuse protection device and a method applied to an electromagnetic voltage transformer. The device comprises a power source module, a shock pulse current determining module, a protection module and a current transformer wherein the power source module is electrically connected with the shock pulse current determining module, the current transformer is electrically connected to the connection wire between the neural point of the electromagnetic voltage transformer and the ground, and the current transformer is electrically connected with the shock pulse current module. The protection module comprises protection resistors and control switches. The two ends of the protection resistors are in series-connection with the two ends of the open triangular loop of the electromagnetic voltage transformer. The control switches are in series-connection between the protection resistors and the open triangular loop. The shock pulse current determining module is electrically connected with the control switches. With the device proposed by the embodiments of the invention, it is possible to rapidly eliminate shock pulse current in an electromagnetic voltage transformer caused by any form of disturbance in a power system in advance and facilitates the suppression of occurrence of ferromagnetic resonance.

Description

technical field [0001] The invention relates to the technical field of fuse safety protection for power systems, in particular to a fuse protection device and method applied to electromagnetic voltage transformers. Background technique [0002] In the distribution network of 66kV and below, the system bus is connected with an electromagnetic potential transformer (Potential Transformer, PT) that monitors the insulation to the ground. Transient impacts caused by lightning strikes on the line, single-phase grounding, combined-air bus operation, drastic load changes, and secondary voltage-load switching may excite ferromagnetic resonance between the excitation reactance of the electromagnetic voltage transformer and the ground capacitance of the system Or cause the iron core of the electromagnetic voltage transformer to saturate, resulting in an impulse pulse current in the fuse protecting the electromagnetic voltage transformer. The amplitude of the pulse current may reach ten...

AI Technical Summary

Problems solved by technology

Transient impacts caused by lightning strikes on the line, single-phase grounding, combined-air bus operation, drastic load changes, and secondary voltage-load switching may excite ferromagnetic resonance between the excitation reactance of the electromagnetic voltage transformer and the ground capacitance of the system Or cause the iron core of the electromagnetic voltage transformer to saturate, resulting in an impulse pulse current in the fuse protecting the electromagnetic voltage transformer. The amplitude of the pulse current may reach tens of amperes, which greatly exceeds the current that the fuse can withstand

Therefore, the aging life of the fuse is severely shortened and the fuse is frequently blown, and the fuse needs to be cut off, which increases the safety risk and the operation and maintenance cost of the unattended station.

[0003] The frequent blowing of fuses has seriously troubled the equipment operation and maintenance unit and seriously increased the cost of operation and maintenance. At present, the method of increasing the rated current of fuses is used to solve the problem of frequent blowing of fuses, which leads to the loss of protection of fuses Electromagnetic voltage transformer ability

Therefore, there are no related technologies and products that can solve the problem of short fuse life and frequent fusing. It is of great significance to research and develop fuse protection technologies and products.

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