Study On The DC System Of Protection Based On The Interference Detection System

The relay protection and automation device has seriously affected the safety and the reliability of Power system. The public DC secondary circuits of substation had been shortcomings in the normal operation. Thus, it is necessary to carry out research and application on the interference test of relay protection directive current system, and anti-interference of secondary circuit in substation。The recent research on anti-interference of secondary circuit in substation was still focus on theoretical analysis, while lack of actual test on DC secondary circuits in electromagnetic environment. As a result, it is very necessary to establish special DC Laboratory and systematically do research on interference test of relay protection DC system.This paper summarizes the harm on recent DC system relay protection taken by to power system interference. analyzed the DC system positive negative second cable grounding and mix AC electricity, and expounds transient process taken by interference on DC system, and the influence of the relay protection Based on extensive references to the current dc system monitoring device, this paper describes how to establish a dc system laboratory including battery, charger, DC bus panel, insulation monitoring device and so on. Using a professional firmware procedure of hardware platform and the application of VC6.0 software, ARM7 processor, DSP5000 chips and other equipment, a simulating platform of relay protection dc interference was finally established. Main disturbances of substation DC systems are simulated on this platform, and several reasonable measures are proposed through simulation and analysis on interference of DC circuits.As an example, a malfunction incident on stability control device in North China Power Grid 500kV substation Jiangjiaying is finally discussed, the scene of the accident and the parameters of the production environment are simulated, so the device's incidents is reproduce, which verifies the accuracy and reliability of the system. Analysis of advantages and disadvantages on traditional measures of DC anti-jamming system new anti-jamming measures are proposed. The effectiveness of the measures are verified based on simulation platform.