Self-Calibration Sensor for Contactless Voltage Measurement Based on Dynamic Capacitance

Abstract

Noncontact voltage measurement has the advantages of simple handling, high construction safety, and not being affected by line insulation. However, in practical measurement of noncontact voltage, sensor gain is affected by wire diameter, wire insulation material, and relative position deviation. At the same time, it is also subject to interference from interphase or peripheral coupling electric fields. This paper proposes a noncontact voltage measurement self-calibration method based on dynamic capacitance, which realizes self-calibration of sensor gain through unknown line voltage to be measured. Firstly, the basic principle of the self-calibration method for noncontact voltage measurement based on dynamic capacitance is introduced. Subsequently, the sensor model and parameters were optimized through error analysis and simulation research. Based on this, a sensor prototype and remote dynamic capacitance control unit that can shield against interference are developed. Finally, the accuracy test, anti-interference ability test, and line adaptability test of the sensor prototype were conducted. The accuracy test showed that the maximum relative error of voltage amplitude was 0.89%, and the phase relative error was 1.57%. The anti-interference ability test showed that the error offset was 0.25% when there were interference sources. The line adaptability test shows that the maximum relative error in testing different types of lines is 1.01%.

Transmission Line Voltage Measurement Utilizing a Calibrated Suspension Grounding Voltage Sensor

“…Some scholars have already started to use the principles of space electric field and capacitance to carry out research related to voltage measurement. A commonly used voltage measurement method is the voltage measurement technology based on the principle of stray capacitance voltage division [ 17 , 18 , 19 ]. The voltage divider is formed according to the coupling stray capacitance between the induced electrode and the measured wire and the inherent capacitance of the designed sensor; the voltage measurement value of the measured wire can be obtained according to the ratio of capacitance mentioned above.…”