Protection method of electric power system

Abstract

The invention discloses a protection method of an electric power system, which comprises a plurality of inlet switches for electric energy to flow in and a plurality of outlet switches for electric energy to flow out on an electric power circuit, and is characterized in that the values of current passing through the inlet switches and the outlet switches are converted into pulses with corresponding relations through a voltage-frequency conversion circuit; and then the pulses are added or subtracted in advance, finally the difference value between all inlet pulse cumulants and all outlet pulse cumulants is calculated through a comparison module, and when the difference value exceeds a preset value, the comparison module controls to cut off each inlet switch. According to the method, when the line breaks down, response is fast, a communication path does not need to be directly erected in a point-to-point mode, fast differential protection can be conveniently achieved through an original communication line, and popularization is convenient.

Description

technical field [0001] The invention relates to the field of power line protection, in particular to a method for protecting a power system. Background technique [0002] Differential protection is a line protection method, and differential protection is often used between the main line and branch lines. The existing differential protection is to obtain parameters such as current and voltage at both ends of the line through the current transformer (CT), and convert them into messages and send them to the computer. Compare the current with the current at the downstream point to see if the current at the upper point is equal to the current at the lower point. If not, it is judged that a fault has occurred and the switch of the line is cut off to cut off the faulty line. However, the process of message writing and manufacturing, transmission, reception, and interpretation involves many links. Not only does it involve many devices and a large amount of calculation, but also the...

AI Technical Summary

Problems solved by technology

However, because this method is to directly transmit the converted pulses to the comparison module point-to-point, in order to achieve this, it is often necessary to re-lay communication lines such as optical fibers, which involves a large amount of construction, thereby greatly reducing the economical and practical nature of this method. Sex, not easy to promote

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