Performance Analysis and Simulating Calculation of Voltage Sensor in Smart GIS

A non-conventional voltage sensor for a 220 kV SMART GIS (gas insulated switchgear) which has been developed is described in detailed. Firstly, this paper lists configuration, principle and the basic technical equation of this sensor. The voltage sensor is well-suited to the geometry of gas-insulated coaxial lines which is called coaxial capacitor. By using the electro-magnetic field analysis function of ANSYS finite element analysis software, the selecting in diameter and length of this sensor is analyzed. Then the influences of temperature, gas density drifts, cylinder´s roundness and bus eccentricity are especially studied. At last, the special two kinds of transient responses are discussed too short circuit at the high voltage level and the power system reclosing with trapped charges. According to the analysis results of errors, it also provides compensation method and theoretical basis for the design of voltage sensor. With careful design and the use of digital signal processing technology, the whole system can meet 0.2% accuracy for metering and provide large dynamic range coupled with good accuracy for relaying use