By hvhipot 
Technical background of frequency conversion series resonance withstand voltage test device
With the continuous development of the power industry, the application of high-voltage power equipment such as transformers, generators, circuit breakers, GIS110kV and 220kV cross-linked polyethylene cables is becoming increasingly widespread. According to the requirements of the “Code for Hand over Test of Electrical Equipment in Electrical Equipment Installation Engineering” GB5015091 and the “Preventive Test Code for Power Equipment” DLT0961996, AC withstand voltage test items are required for the acceptance and annual maintenance of such high-voltage power equipment.
There are three main ways to generate AC voltage withstand test power supplies:
1. Transformer type: Radical test transformer with compensating reactor, power frequency.
2. Induction type: Adjustable inductance resonant system, power frequency.
3. Frequency modulation type: A fixed reactor resonant system, which applies a variable frequency voltage to the test sample through a frequency converter to change the frequency to achieve resonance.
The resonant withstand voltage test method is to change the inductance and test frequency of the test system to make the circuit in a resonant state. In this way, most of the capacitive current on the test sample in the test circuit is offset by the inductive current on the reactor. The energy supplied by the power supply is only the power consumed in the circuit, which is 1/of the capacity of the test sample and the resonant multiple of the system. Therefore, the capacity of the test power supply is reduced and the weight is greatly reduced. The resonant withstand voltage test system is divided into two types according to the adjustment method: inductive and frequency modulation.
The adjustable inductance type resonance test system can meet the withstand voltage requirements, but due to its large weight and poor mobility, it is mainly used in laboratories. The variable frequency series resonant withstand voltage test is a new method and trend of high-voltage testing that utilizes the inductance of a reactor and the capacitance of the test object to achieve resonance, obtaining high voltage on the test object. It has been widely used both domestically and internationally.
HV Hipot Electric Co., Ltd. specializes in the production of series resonance (also known as variable frequency series resonance complete 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.