By hvhipot 
The series resonance withstand voltage test is an indispensable testing method for the daily debugging of electrical equipment. The series resonance circuit has been well used in the withstand voltage test of electrical equipment such as transformers and power cables. This article mainly introduces the functions of the resonance withstand voltage test circuit?
(1) AC voltage withstand test of power cables: Currently, more and more XLPE cross-linked polyethylene insulated power cables are replacing the original oil filled paper insulated power cables both internationally and domestically. However, the traditional DC voltage withstand method has many problems in testing cross-linked cables. As cross-linked cables are high-capacity specimens, the series resonance test method is simple and convenient, and can obtain good AC voltage frequency and waveform. Therefore, it has become an ideal testing method for AC voltage withstand test of cross-linked cables.
(2) AC voltage withstand test for power transformers, reactors, and transformers: The AC voltage withstand test for power transformers, reactors, and transformers has been clearly defined internationally, and can be conducted using either the power frequency voltage test method or the induced voltage test method. The test voltage waveform should be as close to sine as possible; Under this standard, the series resonance test circuit can complete the test under any conditions, and its wide frequency and voltage range have good adaptability to the test object. It can be used with various voltage levels of test objects.
(3) AC withstand voltage test for SF6 enclosed composite electrical equipment: The AC withstand voltage test method is an important method for checking the main insulation condition of the GIS after installation when SF6 is enclosed. In most cases, a series resonance test device is used.
(4) AC withstand voltage test of other equipment: other equipment such as circuit breakers and bushings; The voltage withstand test generally requires a power frequency voltage test. In the case where the power frequency test device cannot meet the on-site requirements, the resonant voltage withstand test method can also be used as a substitute. When using resonance withstand voltage test, due to the small capacitance of the capacitor, the test frequency will be higher. However, a series resonance test device with appropriate compensation capacitance can also be used to reduce the test frequency and achieve a test frequency close to the power frequency.