The Non-contact Measurement Research Of Converter Station High Voltage DC-bus

Nowadays,±800kV UHVDC has become the development trend of the powertransmission field. Voltage measurement of the DC transmission lines is an importantway to ensure the UHVDC system work in secure and stable way. It also has significantreference value in UHVDC project. Voltage measurement can provide safe constructionand economic operation. Converter station is an important part of the modern DCtransmission system. Accurate and reliable bus voltage measurement can provideimportant reference information for the controlling and protecting. Along with theimprovement of bus voltage level, new bus voltage measurement requirements are putforward. This paper works on the discharge process voltage measurement which isproduced by the converter station valve hall DC-side bus. The way to measure voltageis based on electric field measurement. It is a non-contact measurement. This projectdiscusses the operating in measuring principle, measuring way and data processing. Atthe same time, E-Field recording equipment has been successfully developed. It isworks on the discharge process voltage measurement which is produced by theconverter station valve hall DC-side bus.After the analysis of the DC-side bus voltage, this paper put forward anon-contact measurement. According to the relationship between the voltage and theelectric field, electric field measured values can be used to demarcate the voltage. Forthe current lack of an effective device can measure AC and DC electric field which isproduced by the converter station valve hall DC-side bus, the vibration capacitiveelectric field sensor, STM32embedded microcontroller and fiber-optic Ethernet areused to develop a E-field recording equipment. The E-field recording equipment canprovide a long continuous measurement of AC and DC electric fields. Electric fieldmeasurement bandwidth covers DC-50Hz. The measurement data can be long-distancetransported, stored and displayed. The electric filed signal can be measured by vibrationcapacitive electric field sensor. The sensor output is voltage signal. Measurement data istransmitted by fiber-optic Ethernet form STM32to PC. Signal processing software which running on the PC can complete data processing algorithm that based on thelow-pass filter. The data can also be stored and displayed by the software.Based on the achievement of hardware and software, the function of the E-fieldrecording equipment is tested by experiments. The experiments results show that thisequipment can work steady. AC and DC electric fields signal are accurately recorded bythe equipment. E-field recording equipment can be used to record the discharge processelectric fields signal which is produced by the converter station valve hall DC-side bus.The Communication between STM32and PC is safe and reliable. The equipment is aportable instrument with scalable ability and practical value.