The power-frequency withstand test is a crucial procedure for evaluating the insulation properties of electrical equipment, particularly in high voltage systems. This test is commonly performed on CT PT units and is defined by IEC 60060-1.
Test voltage shall have an appropriate value depending on the highest voltage for equipment. During the power-frequency withstand test, the CT PT unit is subjected to a high voltage for a certain duration. The goal is to determine the maximum level of voltage that the unit can withstand without showing any signs of electrical breakdown.
The duration shall be 60s.
Test voltage shall be applied between short-circuited primary winding and earth. The short-circuited secondary winding(s), frame, case (if any) and core (if there is a special earth terminal) shall be connected to the earth.
The test procedure itself involves gradually increasing the voltage level until the desired level is reached. At this point, the voltage is held constant for a set amount of time, typically several minutes. If no breakdown occurs during this time, the unit is deemed to have passed the test.
The power frequency withstand test system designed by wuhan huayi electric power technology, consists of a test transformer and control unit, two parts.It can be customized the voltage and capacity based on the test object and test requirement. the automatic controller, it adopts advanced microelectronic processing technology, all the processes can be set in advance, a full English interface, and the operation is simple and clear. All test items are automatically tested after setting, without manual intervention. This series of automatic power frequency withstand voltage control box adopts the new platform PLC configuration control, which can seamlessly connect various test transformers of different grades, and can perform software calibration, which greatly improves the applicability of the instrument.