Study on Miniaturized UHF Antennas for Partial Discharge Detection in High-Voltage Electrical Equipment

• Main Authors: Jingcun Liu, Guogang Zhang, Jinlong Dong, Jianhua Wang
• Format: Article
• Language: English
• Published: MDPI AG 2015-11-01
• Series: Sensors
• Subjects: equiangular spiral antenna; high-voltage electrical equipment; microstrip balun; partial discharge; ultra-high-frequency antenna
• Online Access: http://www.mdpi.com/1424-8220/15/11/29434

Detecting partial discharge (PD) is an effective way to evaluate the condition of high-voltage electrical equipment insulation. The UHF detection method has attracted attention due to its high sensitivity, strong interference resistance, and ability to locate PDs. In this paper, a miniaturized equiangular spiral antenna (ESA) for UHF detection that uses a printed circuit board is proposed. I-shaped, L-shaped, and C-shaped microstrip baluns were designed to match the impedance between the ESA and coaxial cable and were verified by a vector network analyzer. For comparison, three other types of UHF antenna were also designed: A microstrip patch antenna, a microstrip slot antenna, and a printed dipole antenna. Their antenna factors were calibrated in a uniform electric field of different frequencies modulated in a gigahertz transverse electromagnetic cell. We performed comparison experiments on PD signal detection using an artificial defect model based on the international IEC 60270 standard. We also conducted time-delay test experiments on the ESA sensor to locate a PD source. It was found that the proposed ESA sensor meets PD signal detection requirements. The sensor’s compact size makes it suitable for internal installation in high-voltage electrical equipment.