Research Of Insulating Parameter Measure In IT Power Distribution System

With the rapid development of national economy, each aspect of industry have agrowing demand for energy management, therefore, the structure of the power grid tendto be more and more complex, and it’s capacity is bigger, how to ensure the safety andstability of power grid in key areas are particularly important. IT distribution systemhave been applied more and more with its unique advantages, it reduce the heavy losscaused by insulation fault and bring industry production huge economic benefits.So,Insulation monitoring also become an important part of IT power distribution system.Based on the research of existing measuring insulation resistance method, bing theperiodic impulsive stimulation signal and microcomputer control system in theinsulation resistance measurement system in order to realize the online insulationresistance measurement,improve the security and reliability of IT distribution powersupply system.This paper first state the research status of measuring insulation resistance at homeand abroad and commonly used measuring method.And then take the shortcomings andthe insufficiency of existing measuring method into consideration, raise the measuringmethod of insulation resistance and capacitance that based on the periodic impulsivestimulation signal and give related simulation results, at the same time, designinsulating parameter measurement system’s hardware platform circuit implementationscheme according to relevant standards,and gives the software flow chart and functionfeatures list, finally test the parameters of the system hardware and software.Through the analysis of distribution system IT one-phase ground fault andinsulating parameter online monitoring principle,summarize the computational method of the bus insulation resistance and capacitance, and deduce the concrete mathematicscalculation formula, then design and develop the hardware and software inmeasurement system according to the principle of measuring insulation resistance.Hardware circuit based on PIC24H microprocessor chip, its core is themeasurement circuit, software design and implementation, each program modules areall in a single file, eventually, through insulating parameter calculation procedure calleach part of the combination of as a unit.