By hvhipot 
HV Hipot Electric Co., Ltd. specializes in producing series resonance (also known as series resonance withstand voltage test device). Next, we will share with you an introduction to the series resonance system.
The series resonance test equipment is mainly used for AC withstand voltage testing of 6kV-500kV high-voltage cross-linked cables, 6kV-500kV transformers, generators, GIS and SF6 switches, and other power high-voltage equipment such as busbars, bushings, and transformers. A device that uses tuned inductors and load capacitors to generate series resonance at power frequency, with pilot control to obtain power frequency test voltage. Series resonance testing equipment is widely used in industries such as power, metallurgy, petroleum, and chemical engineering, and is suitable for the handover and preventive testing of high-capacity, high-voltage capacitive specimens.
Components: consisting of variable frequency power supply, excitation transformer, reactor, and capacitive voltage divider.
The series resonance test equipment is mainly used for cross linked rubber and plastic power cables of 10kV, 35kV, 110kV, 220KV, and 500KV, variable frequency AC withstand voltage tests of 66kV, 110kV, 220kV, and 500KV combination electrical appliances (GIS), and power frequency AC withstand voltage tests of hydraulic and thermal generators or power transformers. The basic principle is to use an adjustable (20-300Hz) series resonance test equipment to resonate with the capacitance of the test object to generate an AC test voltage.
Principle of series resonance test equipment
When the circuit frequency f=1/2 π√ LC, resonance occurs in the circuit, and the voltage on the test sample is Q times the output voltage of the excitation transformer high voltage end. Q is the system quality factor, which is the voltage resonance multiple, generally ranging from tens to hundreds or more. First, adjust the output frequency of the variable frequency power supply to induce series resonance in the circuit, and then adjust the output voltage of the variable frequency power supply under the condition of circuit resonance to achieve the test value of the sample voltage. Due to the resonance of the circuit, a smaller output voltage of the variable frequency power supply can generate a higher test voltage on the test sample CX.