AC Resonant Test Systems for High-Voltage Withstand Testing

An AC resonant test system is a high-voltage testing system that uses resonance technology to generate AC test voltage for insulation withstand testing. It is particularly suitable for high-capacitance test objects where conventional AC test equipment may require a larger power supply capacity. The system typically consists of a variable-frequency power supply, excitation transformer, reactor and measurement/control components.

An AC resonant test system uses a variable-frequency power supply and reactor to create a resonant circuit with the capacitance of the test object. The system adjusts the output frequency to find the resonance point, allowing the required AC test voltage to be generated under controlled conditions. Depending on the configuration, automatic frequency finding and automatic test functions can simplify the testing process.

Variable frequency resonance allows the system to achieve the required high AC test voltage by matching the test circuit's resonant frequency. This approach is especially useful for high-capacitance test objects, such as long power cables and other high-voltage electrical equipment. The test frequency can be adjusted according to the test object and applicable testing requirements.

AC resonant test systems can be used for AC withstand testing of high-voltage electrical equipment, including power cables, transformers, GIS and other capacitive test objects. The appropriate system configuration depends on the required test voltage, test frequency, capacitance and test-object characteristics.

The appropriate AC resonant test system should be selected according to the required test voltage, test frequency, capacitance of the test object and expected test conditions. The reactor configuration and system capacity should also match the electrical characteristics of the test object. Providing the test object, required voltage and capacitance to the supplier can help determine a suitable system configuration.

Failure to find resonance may be caused by incorrect wiring, an unsuitable frequency range, insufficient excitation power or a low quality factor (Q value) in the test circuit. The test connections, frequency range and excitation conditions should be checked before repeating the frequency-finding process. If the system still cannot find a resonance point, the test-object parameters and system configuration should be reviewed.