Research On Application Of Insulation Monitoring Technology For DC System Of Power Plant

The DC system is an important part of the power plant,is the normal operation of the power equipment important control circuit,relay protection device,automatic device,control device and other system two times;two times the system working condition of DC system and electrical correct action rate is closely related to affect the safe and reliable operation of the whole power plant.Therefore,in order to ensure the long and stable operation of the power plant,a fully functional and stable DC equipment must be configured.However,due to DC system insulation function monitoring device of old plant technology is single,when the DC system fault can not get timely analysis,processing,isolation or solve,often will expand the sc ope of power,equipment damage,destroy the stable operation of power plant,power plant and even cause "non stop" accident,resulting in unnecessary loss of power and even the power plant.Therefore,it is very important to study how to reconstruct the DC insulation monitoring device in the old factory.This paper first introduces the function and structure of DC system,DC ground fault hazards,principle and types are comprehensively analyzed,aiming at Salaqi power plant one point grounding trip event analysis of the causes and take preventive measures.Through the analysis of the current DC grounding detection method,using the principle of balance bridge + unbalanced bridge is designed,and studied the DC system into communication parameters and working methods,proposed device insulation monitoring and active communication into the protection of a combination of DC system model,and analyzes the function the structure of the device and the structure of hardware and software.Through the test and the actual operation shows that the device realizes the comprehensive monitoring system of DC bus grounding fault and grounding fault,and can detect and locate the DC grounding fault,and line selection and real-time monitoring system into DC AC component,to promptly eliminate fled into fault.To ensure the good running state of the DC system of the power plant and lay a solid foundation for the safe and reliable operation of the power plant.