Development Of Wireless Calibration System For Capacitive Equipment Online Monitoring Device

At present,the use of on-line monitoring device for high-voltage substation capacity equipment in the state data collection and analysis to determine the degree of insulation degradation and then carry out the corresponding maintenance work has become a trend.Therefore,to ensure the capacitive equipment on-line monitoring device measurement performance of accurate and reliable to ensure the safe operation of the power grid is of great significance.In this paper,according to a new capacitive equipment on-line monitoring device on-site verification method of the Zhejiang Electric Power Research Institute,we completed the wireless calibration system design.This calibration system solves the inconvenience caused by the reference voltage transmission in the calibration using long distance cable.The innovative point of this calibration system include the reference voltage wireless transmission scheme,and program-controlled phase modulation and amplitude modulation check current generation part with function of the frequency adaptive tracking.The entire wireless calibration system consists of reference voltage acquisition device and check the current generating device composed of two parts,are lithium battery-powered portable devices.The reference voltage acquisition device obtains the secondary voltage of the substation voltage transformer and performs the FM modulation and the wireless transmission.The check current generating device receives the reference voltage and outputs the check current as the frequency and phase reference output current.In the check current generating device,the frequency doubling phase lock module,the AC voltage generating module and the AC voltage to current module together constitute the core actuating mechanism of the check current to realize the frequency adaptive tracking and program-controlled phase modulation Output;control module,human-computer interaction module and a series of detection module together constitute the device control coordination mechanism,responsible for the operation of the device detection,internal data communication and human-computer interaction.The project finally completed the capacitive equipment on-line monitoring device wireless calibration system testing machine in-kind development,Zhejiang Institute of Metrology calibration report shows that the output check current phase shift maximum error of 3°,RMS full-range error in the 1%or less.