By hvhipot 
The AC series resonance under HV Hipot Electric Co., Ltd. power can help many power workers conduct various power tests more conveniently.
Variable frequency series resonance device, also known as variable frequency series resonance AC withstand voltage test device, variable frequency resonance, variable frequency series resonance, series resonance, frequency modulation series resonance, series resonance withstand voltage test device, series resonance test device, cable withstand voltage test device, power frequency withstand voltage test device, high-voltage cross-linked cable AC withstand voltage test device, AC withstand voltage test device FM resonance, portable cable AC withstand voltage testing device, generator AC withstand voltage testing device, GIS AC withstand voltage testing equipment, etc. are widely used in industries such as power, metallurgy, petroleum, chemicals, etc. The frequency conversion series resonance tester is suitable for testing large capacity and high voltage capacitors, such as generators tra nsformer、 GIS、 Switching experiments and preventive testing of high-voltage cross-linked cables, transformers, and installed pipelines.
The power supply is provided by the frequency controller, and the test voltage is initially boosted by the excitation transformer, so that high voltage is applied to the reactor L and the test product CX, and the circuit is in series resonance state. Change the output frequency of the FM controller; Adjust the output voltage of the inverter controller to achieve the desired voltage value on the high voltage of the test sample.
The resonant frequency of the loop depends on the capacitance of the test capacitor CX and the inductance L of the reactor, as well as the resonant frequency.
Variable frequency series resonance is a resonant current filtering circuit that can improve the distortion of power waveform, obtain better sine voltage waveform, and effectively prevent the harmonic breakdown of the test object from being accidentally damaged. Variable frequency series resonance operates in a resonant state.
When the insulation point of the test product is broken down, the current immediately becomes detuned, and the circuit current rapidly drops to one tenth of the normal test current. When flashover occurs, the resonance condition is lost, the short-circuit current immediately decreases, the high voltage disappears immediately, and the arc is extinguished. The reconstruction process of restoring voltage is very long, and it is easy to disconnect the power supply after reaching the flashover voltage again. Therefore, it is suitable for insulation withstand voltage testing of high voltage and large capacity power equipment.