Design of circle shaped loop antenna as partial discharge sensor

Abstract

This paper discusses the design and implementation of circle shaped loop antena to measure partial discharge (PD). The loop antenna is designed to measure PD induced EM wave in air and liquid insulation. The PD in air and liquid induces EM wave in the frequency range up to 100 MHz and 200 MHz, respectively. The circumference and the number of rounds of loop antenna affect the antenna characteristics. In the design, the circumference of a loop antenna is set to be a tenth of a wavelength of PD induced EM wave. The conductor wire length of loop antennas is set to be 30 cm, 20 cm, and 15 cm to be able to detect the PD induced EM wave signal in the frequency range up to 100 MHz, 150 MHz, and 200 MHz, respectively. The circle shaped loop antennas with 9.6 cm, 6.4 cm, and 4.8 cm in diameter have been designed and implemented. The designed loop antennas were applied to measure PD in high voltage laboratory. The needle-plate electrodes in air is used as a PD source. The test results showed that the circle shaped loop antennas were able to detect and measure PD.