Design and Development of Contact-Less Voltage Sensor

Abstract

A new and low-cost system for contactless measurement of an alternating voltage in an insulated conductor is presented in this work. Capacitive effect based contactless sensors are proposed to measure AC voltage in an insulated cable. A step by step procedure has been followed to develop an accurate and reliable prototype of the proposed method. First, a contactless U-Shaped Rectangular sensor prototype has been developed in the laboratory and verified its effectiveness towards the measurement of AC voltage. A cylindrical shaped probe has been developed next and tested it in the laboratory. The results from the experimental studies conducted on the developed prototypes show that the cylindrically shaped sensor is more accurate for the measurement of AC voltage. As a further development, the cylindrical capacitor is improved to the dual capacitive cylindrical sensor. A prototype for improved cylindrical model has been developed and tested in the laboratory for different frequency and voltage conditions. Instead of sophisticated methods, a simple FFT analysis of detected signal from sensor presented in the report. The worst-case error observed from the experimental studies conducted on the improved contactless cylindrical prototype was ±0.77%.