By hvhipot 
HV Hipot Electric Co., Ltd. specializes in producing series resonance (also known as variable frequency series resonance test device). Next, we will share with you the introduction of GIS variable frequency series resonance test.
Preparation work before GIS AC withstand voltage test
GIS equipment should be debugged and qualified. After passing the insulation characteristic test, SF6 gas should be inspected at rated pressure. The TA secondary in the test circuit should be short circuited and grounded. The lightning arrester and protective spark gap in the test circuit should be disconnected from the tested GIS. Before the experiment, check whether the high-voltage cables and overhead lines, voltage transformers, lightning arresters, and high-voltage outgoing lines of power transformers are disconnected from the GIS before conducting the series resonant AC withstand voltage test.
Series resonance test device
Connect and check. During the experiment, if an isolation switch or tee is used to connect the detection sleeve, the SF6 gas in the isolation switch or tee chamber should be recovered, the end cover of the isolation switch or tee should be removed, and then the test sleeve, connecting fittings, pressure equalization components, etc. should be installed. Finally, the chamber should be evacuated and filled with SF6 gas. If GIS is of the common tube type, the connection phase of the detection sleeve should be carefully checked.
How to segment and withstand voltage in high-capacity GIS
If the overall capacitance of GIS is large, the withstand voltage test can also be conducted in sections. According to the test plan, check whether the positions of GIS isolation switches, circuit breakers, and grounding switches comply with the methods in the test plan. Non test compartment circuit breakers and isolation switches should be in the open position, and grounding switches should be in the closed position. When the expansion part of GIS is subjected to voltage resistance, the adjacent equipment should be powered off and grounded. Otherwise, special measures should be taken to deal with the adverse effects of sudden breakdown on the original equipment. Each phase should be tested, and non test phases and casings should be grounded together. If it is suspected that the fracture of the circuit breaker and isolating switch has been damaged or disassembled during transportation and installation, a voltage withstand test should be conducted between the fracture surfaces.
During the experiment, according to the actual situation on site, arrange the experimental equipment reasonably, try to make the wiring of the experimental equipment compact and stable, and use a dedicated grounding wire for the grounding wire.