By hvhipot 
HV Hipot Electric Co., Ltd. specializes in producing series resonance (also known as AC withstand voltage test device). Next, we will share with you the calculation method of resonance voltage.
Resonant voltage is a professional term used in series resonance testing, referring to the voltage generated when a series resonance circuit generates resonance conditions. The resonant voltage we often hear refers to the voltage magnitude of the series resonance testing device during the testing process.
When we provide after-sales service to customers on site, they often ask me why the 10kV system voltage is 22kV and how much the 35kV system voltage needs to reach to be considered qualified. Today, we will share with you the calculation method of series resonant voltage.
Calculation method of resonant voltage
Taking the 10kV system as an example: YJV22-8.7/10 is the model of the cable, with a voltage level of 10kV and a phase voltage of 8.7kV. According to the preventive testing standard, the maximum voltage of the series resonance test device for the cable is 2.5U0, which is 8.7 * 2.5 ≈ 22kV. According to different standards, some units also determine whether the cable is qualified based on 2U0. Regardless of which type is used, the resonance voltage of the series resonance test is strictly tested according to the customer’s specified requirements. If it is a 35kV system, its resonance voltage is 21 * 2.5U0 ≈ 52kV; Similarly, the calculation method for the resonant voltage of 110kV and 220kV is the same, but it should be noted that the magnification is different. For example, in the 110kV system, the maximum voltage of the cable in the series resonance test is 64 * 1.7U0 ≈ 109kV, and so on. If you have any questions about the magnification, you can refer to the “Electrical Equipment Handover Test Standard” for clear regulations.