Development Of Intelligent Capacitive Current Testing Device For Power Transmission System

With gradually expanding the scale of C hina's urban and rural distribution network,the distribution network system leads to the rapid growth of bus capacitance current,the arc suppression coil capacity allocation,security management is not in place,many problems emerged.Because of the arc suppression coil capacity configuration is not reasonable,because when this occurs in a system of relatively short circuit fa ult will cause the grounding arc to extinguish causing a fire,substation bus short circuit,switch cabinet burning and a series of failures,causing huge security risks to the normal operation of the power system and the people's life and property.In view of the resonant grounding system can effectively avoid the arc grounding over voltage,so many domestic substations have carried out a series of rectification work,the original neutral grounding mode or grounding by low resistance mode to replace the Petersen coil grounding mode,so that when the power of single relatively short circuit capacitor current through bus and flows through the inductive current of arc suppression coil can compensate for each other,to avoid the occurrence of the grounding arc,which occurs in power system single phase short circuit during the power transmission will not immediately stop,for the maintenance of precious time for electrical maintenance personnel.For the neutral point of the power transmission system of arc suppression coil grounding line,when the transformation of the new substation or the existing distribution system,should be timely to the arc extinguishing device and system tuning degree function test,in order to check the Petersen coil capacity is sufficie nt.O nly on system bus line in the measurement of capacitance current in order to reasonable compensation capacity,adjustment of arc suppression coil and so on system bus to ground capacitance current measurement is very important.This paper firstly analyzes the importance of measurement of busbar capacitance current,method of capacitance current measurement system are introduced and compared,the frequency sweep measuring method with measuring safety,simple operation,easy implementation,the frequency sweep method to realize the system capacitive current to ground test work.The test principle of the frequency sweeping method is analyzed,the simulation model was built by using MATLAB simulation software,and combined with the related knowledge of embedded electronic technology,design the hardware circuit and software flowchart of frequency sweeping method testing device.The design of the test system to the current demand of the power system and convenient use point of view,STM32F103 Series MCU with high performance as the main control chip,using color LCD screen with touch function as display and control devices,and design a friend Good man-machine interface,realize the measurement of intelligence and security.