By hvhipot 
Customers often ask what is the difference between series resonance and parallel resonance, or what are the conditions for series resonance and parallel resonance during the testing process. Firstly, whether it is parallel resonance or series resonance, they are both structural branches of the series resonance testing device, with only a slight difference in their names. Now, let’s share the relevant knowledge of series resonance.
What is series resonance
With the preventive testing of electrical equipment for large capacity and high voltage, it is recommended to use power frequency withstand voltage for insulation performance testing, which eliminates the requirement of using DC high-voltage generators for insulation performance testing of electrical equipment. Although both belong to destructive tests, after long-term research, the use of power frequency withstand voltage has better stability and safety compared to DC withstand voltage. Due to the large capacity and high voltage of electrical equipment, power frequency withstand voltage equipment such as oil immersed test transformers often cannot meet the testing requirements. In China, in order to achieve this goal, measurement is basically achieved through frequency conversion series resonance.
Variable frequency series resonance, “variable frequency” refers to the resonant condition generated by adjusting the variable frequency range in a series resonant circuit. “Series” refers to the connection method in the entire circuit. When connected in series, the voltage is added and the current remains unchanged. “Resonance” refers to the resonant circuit, and when combined, it is commonly referred to as the series resonant test device.
After we receive the experimental project, we need to analyze what the subject of the experiment is, such as power cables, transformers, GIS combiners, busbars, etc. The voltage applied to different contents is different. For example, for the same transformer, the voltage level of neutral point grounding and ungrounded is different, and the wiring is also different. The voltage and capacity directly affect the configuration scheme of the series resonance test device. The configuration scheme refers to the connection method and series method? How to string? In summary, the condition for achieving series resonance is when the capacitance impedance is equal to the inductance impedance, which can generate resonance conditions.
HV Hipot Electric Co., Ltd. specializes in the production of series resonance (also known as AC withstand voltage test equipment) and has been engaged in the electrical measurement industry for many years. Its products have first-class quality and welcome customers to come and purchase.