Porcelain cap and pin insulators are by far the most popular suspension insulators in high voltage(HV) distribution networks all around the world.Inspection and condition monitoring of HV insulators is also very impor...Porcelain cap and pin insulators are by far the most popular suspension insulators in high voltage(HV) distribution networks all around the world.Inspection and condition monitoring of HV insulators is also very important to the utility companies because of the critical and vital role that they play in distribution systems.In terms of safety, practicality and ease of use,remote detection methods are more popular among the line technicians.A new remote condition assessment method based on electromagnetic radiations from porcelain insulators is presented in this paper. In a lab environment,a string of two porcelain insulators is energized by a 45 kV transformer.Electromagnetic radiations due to the partial discharge activities inside the porcelain insulator are captured by passive sensors and antennas. Two cases of defective insulators on a two insulator string are studied here.The first case focuses on the effect of contaminated porcelain shells on radiation signature of partial discharges.A polluted porcelain shell with ESDD level of 0.03 mg/cm^2 was first tested.The second case studies the effect of cracks of an intentionally-cracked porcelain shell. The cracked insulator is also tested on a two insulator string.To compare the partial discharge radiation signature of different faulty insulators,phase resolved graphs were developed.The electromagnetic radiated signature of a polluted insulator and a cracked insulator was calculated and compared using phase resolved graphs.展开更多
文摘Porcelain cap and pin insulators are by far the most popular suspension insulators in high voltage(HV) distribution networks all around the world.Inspection and condition monitoring of HV insulators is also very important to the utility companies because of the critical and vital role that they play in distribution systems.In terms of safety, practicality and ease of use,remote detection methods are more popular among the line technicians.A new remote condition assessment method based on electromagnetic radiations from porcelain insulators is presented in this paper. In a lab environment,a string of two porcelain insulators is energized by a 45 kV transformer.Electromagnetic radiations due to the partial discharge activities inside the porcelain insulator are captured by passive sensors and antennas. Two cases of defective insulators on a two insulator string are studied here.The first case focuses on the effect of contaminated porcelain shells on radiation signature of partial discharges.A polluted porcelain shell with ESDD level of 0.03 mg/cm^2 was first tested.The second case studies the effect of cracks of an intentionally-cracked porcelain shell. The cracked insulator is also tested on a two insulator string.To compare the partial discharge radiation signature of different faulty insulators,phase resolved graphs were developed.The electromagnetic radiated signature of a polluted insulator and a cracked insulator was calculated and compared using phase resolved graphs.
