By hvhipot 
Power frequency series resonance withstand voltage test device? HV Hipot Electric Co., Ltd. specializes in producing power frequency series resonance withstand voltage test devices, with a wide selection of products. When looking for a power frequency series resonance withstand voltage test device, choose HV Hipot Electric Co., Ltd..
The power frequency series resonance withstand voltage test device 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, transformers). A device that uses tuned inductors and load capacitors to generate power frequency series resonance and obtain power frequency test voltage.
The voltage, waveform, frequency, and distribution of voltage inside the insulation of the tested object in the power frequency series resonance withstand voltage test device are relatively consistent with the actual operating conditions, thus enabling more effective and accurate detection of insulation defects. The power frequency series resonance withstand voltage test should be conducted only after the insulation resistance and absorption ratio measurement, DC leakage current measurement, and dielectric loss tangent value tg δ measurement of the tested object are all qualified. If insulation defects have been identified in these tests, efforts should be made to eliminate them and retest before conducting AC withstand voltage tests to avoid unnecessary damage. Principle of power frequency series resonance withstand voltage test device
The wiring of the power frequency series resonance withstand voltage test device should be determined according to the requirements of the test object (voltage, capacity) and the existing test equipment conditions. Usually, the test transformer is a complete set of equipment (including control and voltage regulation equipment), and the voltage regulation and control circuits are simplified as shown in Figure 1.
Figure 1 shows a test transformer with cascade boosting. When the output voltage of the test transformer cannot meet the required voltage for the test, the cascade boosting method can be used.
It should be noted that during cascade boosting, the rated voltage of the two test transformers should be the same, and the actual output of BS1 at this time should be the ratio of apparent power to the total capacity of the device (i.e. utilization rate), which is 2UeI/3UeI=67%. The test sample subjected to AC withstand voltage is generally a capacitive load. When the capacitance of the test sample is large, the capacitive current will cause a significant voltage drop on the leakage reactance of the test transformer. Due to the opposite phase between the voltage on the test sample and the voltage on the leakage reactance of the test transformer, it is possible for the voltage on the test sample to be higher than the output voltage of the test transformer. Therefore, it is required to directly measure the voltage on the test sample.
Attention: 1 When the test sample is an organic insulating material, it should be touched immediately after the test. If there is widespread or localized heating, it is considered to be poor insulation and should be treated immediately before conducting the test. 2. For equipment with interlayer insulation or organic insulation materials, if the insulation resistance after the withstand voltage test decreases by 30% compared to before, the test sample is considered to be unqualified. 3. During the experiment, if the surface of the test sample experiences sliding discharge or air discharge due to factors such as air humidity, temperature, and surface dirt, it should not be considered as unqualified. The test sample must be cleaned and dried before proceeding with the experiment.