A partial discharge detection method for switch cabinets based on a second-order circuit

Abstract

To achieve high-sensitivity live detection for partial discharge （PD） pulses in high-voltage switch cabinets， a detection method based on a second-order circuit is proposed. Firstly， a pulse detection circuit that includes a charged display device and a detection impedance is constructed， and then the electrical parameters of the sensing and display units are measured and analyzed. Subsequently， a second-order circuit suitable for live detection is introduced， and the impact of second-order circuit， capacitance， and inductance parameters of the charged display device on safety， reliability and detection sensitivity is studied. Finally， a test is carried out on the proposed method using a 10 kV metal-clad switchgear and a charged display device. The results reveal that the detection impedance of the second-order circuit does not undermine the safe operation of the switchgear and the charged display device. Its detection sensitivity is 1.6 times that of the high-frequency current transformer mounted on the earth wire of the switchgear.

Keywords

• switch cabinet
• partial discharge
• charged display device
• second-order circuit
• detection impedance