By hvhipot 
GIS AC withstand voltage test? HV Hipot Electric Co., Ltd. Power specializes in producing AC voltage withstand machines, with a wide range of product options and 15 years of professional electrical testing experience. When looking for AC voltage withstand machines, choose HV Hipot Electric Co., Ltd. Power.
Faced with the increasingly expanding power grid load, traditional open type equipment is experiencing a surge in operational failures and frequent maintenance, which requires us to use a more reliable device. GIS has emerged as a result. Compared to traditional open devices, GIS has high reliability, strong practicality, good economy, and reduced overall costs. Of cHV Hipot Electric Co., Ltd.se, although GIS has these advantages, in order to ensure the normal operation of GIS, we need to regularly conduct AC withstand voltage tests on GIS equipment, and the series resonance test device is the first choice for conducting withstand voltage tests.
Principle:
Using the principle of series resonance, the excitation transformer is used to excite the series resonance circuit, and the output frequency of the variable frequency controller is adjusted to make the circuit inductance L and the test sample C resonate in series. The resonance voltage is the voltage applied to the test sample.
Application:
Widely used in industries such as power, metallurgy, petroleum, and chemical, it is suitable for the handover and preventive testing of high-capacity, high-voltage capacitive samples.
After the on-site installation and debugging of GIS equipment are completed, a voltage withstand test must be conducted. The purpose is to check whether the overall insulation performance is intact after installation, and verify whether there are various hidden dangers (such as installation errors, damage during packaging, transportation, storage, and installation debugging, foreign objects, etc.) that may cause internal faults.
1. Requirements for test samples during communication pressure resistance
① The test sample should be fully installed, inflated to the rated density, and undergo a sealing test and gas humidity measurement before conducting a pressure test;
② Before the withstand voltage test, the insulation resistance of the test sample should be measured;
③ Before the withstand voltage test, all secondary windings of current transformers on GIS should be short circuited and grounded;
④ Before the withstand voltage test, high-voltage cables, overhead lines, power transformers, and electromagnetic voltage transformers (if using a variable frequency power supply, the electromagnetic voltage transformer will not cause magnetic saturation after frequency calculation and can withstand voltage together with the main circuit), lightning arresters, and protective spark gaps should be isolated;
⑤ Each part of the GIS main circuit should undergo a voltage withstand test.
2. AC withstand voltage test voltage value and application of test voltage
The voltage value for the on-site communication withstand voltage test is 80% of the voltage value applied during the factory test. The prescribed test voltage should be applied between each phase conductor and the casing, one phase at a time, and the conductors of other phases should be connected to the grounded casing. The test power supply can be connected to any part of the tested phase conductor. The selected test procedure should ensure that each component is subjected to at least one test voltage. When formulating the test plan, it is necessary to also pay attention to minimizing the number of repeated tests on solid insulation as much as possible. For example, test voltages should be introduced as much as possible in different parts of GIS. 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.
3. GIS AC voltage withstand test criteria
If each component of GIS has withstood the specified test voltage according to the selected test procedure without breakdown discharge, the entire GIS is considered to have passed the test. During the experiment, if breakdown discharge occurs, the following steps can be taken:
① Repeat the test, and if the equipment can still withstand the specified test voltage, it is considered that the discharge is self recovery discharge, and the withstand voltage test has passed;
② If the repeated withstand voltage fails, the equipment must be disassembled, the discharge interval opened, the insulation damage carefully inspected, necessary repair measures taken, and the prescribed withstand voltage test conducted.