Research And Implementation Of Non-contact High Voltage DC Electroscope

DC transmission project has the unique advantages in large capacity and long-distance transmission,it has become the main means of power transmission in the transmission field.The operation state of DC transmission project directly determines the safety and stability of power network.The measurement technology of electrical inspection is an important way to confirm electrification state of high voltage transmission lines and to judge the safe distance of live working.With rapid development of Multiterminal DC transmission and VSC-HVDC.The running voltage level is continuously diversified.The expansion of application scope makes it more and more problems in construction and maintenance.Therefore,the new demand of electrical inspection method aiming at DC transmission is proposed,and this paper carried out the research on non-contact High Voltage DC electroscope.The electroscope can be used to detect the high-voltage direct current transmission lines and the charged state of electric equipment.It has the functions of wireless data transmission,audible alarm,liquid crystal display and so on.The characteristics of safe and reliable,convenient operation,and easy to carry.Aiming at Voltage Source Converter based High Voltage DC Transmission at ±160kV level in Nanao island.A double polarity transmission calculation model based on the actual running busbar of jinniu converter station is set up,the electric field distribution characteristics of the line are analyzed deeply.According to the principle of electric field generated by line voltage,the non-contact measurement method by using electric field to caculate the voltage is proposed.Based on the vibration-type capacitive sensing principle,an electrode-type packaged probe based on the EST102 vibration capacitance sensor and the corresponding signal conditioning circuit were designed.This paper describes the functional composition and hardware part of the non-contact High Voltage DC electroscope system.The necessity and corresponding working principle of the master-slave safety dual monitoring system for electroscope were introduced.The power inspection system adopts a functional modular design,selects the appropriate electronic components to complete the hardware design of each module circuit,and explains some necessary application function modules of the electroscope.Finally,the function of wireless data transmission in a strong electromagnetic environment is analyzed.Through CC2530 wireless radio frequency module based on ZigBee protocol stack,close range communication between host and slave of electroscope is achieved.The portable electroscope gateway node is set up by adopting CC2530 module and GSM/GPRS A6 module.The data interaction between the slave of electroscope and the upper computer center is realized by using the wireless transmission network with the characteristics of anti-electromagnetic interference of the electromechanical system.Simulate the use environment of the electroscope and set up a high-voltage experimental platform to conduct safety experiments on the main part of the electroscope prototype and test the function of the electroscope.In the HVDC converter station,aiming at electric transmission line ±160kV level,function test of electroscope is completed,Field experiment results show that the electroscope system can correctly judge charged state under the environment of strong electric field.Alarm and wireless communication performance is very good,the correctness of the dc non-contact high voltage electroscope is validated.