Analysis and Solution of Voltage Rise Phenomenon in Small Inductive Current Switching Test of High Voltage AC Disconnector

During the small inductive current switching test of high-voltage AC disconnector, the short-circuit impedance of the power frequency test transformer leads to the phenomenon of voltage rise on the power supply side of high-voltage AC disconnector after tripping. For the small inductive current switching test of ultra-high voltage AC disconnector, due to the large short-circuit impedance of the power frequency test transformer used, the voltage rise phenomenon on the power supply side is particularly significant. Since the voltage rise on the power supply side will improve the test conditions, and the relevant standards stipulate that the voltage rise on the power supply side in small inductive current switching test should not exceed 10%, the voltage rise phenomenon brings certain difficulties to the small inductive current switching test. This paper analyzes the nature of the voltage rise phenomenon in small inductive current switching test of high-voltage AC disconnector, proposes an improved small inductive current switching test circuit, and verifies the validity of the proposed improved circuit through theoretical analysis, simulation calculation and actual test. At the same time, this paper also gives the selection method of inhibitory capacitance in the improved circuit.