The series resonance under Wuhan UHV can help many power workers conduct various power tests more conveniently.

The series resonance withstand voltage test method is an important method for testing the insulation performance of equipment in power systems. The following is a detailed explanation of the method, including its principles, steps, and precautions:

principle

The series resonant withstand voltage test method is based on the characteristics of the series resonant circuit and the capacitance properties of the insulation material of high-voltage equipment. By connecting the tested device in series with the power supply, a resonant circuit is formed, and the power supply frequency is adjusted to achieve a resonant state of the circuit. In the resonant state, the current in the circuit reaches its maximum value, and the capacitive properties of the insulation material of the tested device can cause a lag phase of the current, causing the current and voltage in the resonant circuit to no longer be in the same phase relationship. According to the characteristics of a series resonant circuit, when the current and voltage are no longer in phase, the impedance of the circuit will decrease and the current will increase. Therefore, when there is insulation loss or breakdown phenomenon in the insulation material, the current of the circuit will significantly increase.

step

Equipment preparation: Ensure that the equipment to be tested is suitable and correctly connected to the testing circuit. If necessary, perform equipment preprocessing and protection.

Resonant circuit adjustment: Select appropriate resonant circuit parameters based on the characteristics of the tested equipment. This includes selecting appropriate frequencies and capacitance values to ensure that the resonance conditions meet the testing requirements.

Pre charging: Perform pre charging operation before applying high voltage. By gradually increasing the voltage, strain mutations and equipment damage can be avoided.

Apply high voltage: Connect the high voltage power supply to the resonant circuit and gradually increase the voltage until it reaches the predetermined test voltage. Maintain voltage stability and record relevant parameters.

Observation and measurement: Observe the data of equipment and measuring instruments during the testing process. Pay attention to any abnormal phenomena, discharges, or malfunctions. Check the leakage current, dielectric loss and other parameters of the equipment.

Adjusting the resonant circuit: If it is necessary to adjust the resonant circuit to achieve appropriate testing results, the capacitance value and frequency can be adjusted appropriately.

End of test: After completing the test, gradually reduce the voltage and cut off the high-voltage power supply. Dismantle the testing circuit and perform necessary safety operations.

matters needing attention

Equipment selection: Suitable series resonant equipment should be selected, including series resonant transformers, series capacitors, and series inductors. The rated voltage and current of the equipment must meet the requirements of the tested equipment.

Environmental conditions: The testing equipment and the tested equipment should be in a dry, dust-free, and non corrosive gas environment to ensure the accuracy and safety of the testing.

Grounding: Both the testing equipment and the tested equipment need good grounding to ensure the safety of the test. The grounding resistance should meet the specified requirements.

Protective measures: Necessary protective measures need to be taken during testing, such as installing overvoltage protection devices, overcurrent protection devices, etc., to prevent equipment damage and personal safety accidents.

Test parameters: During testing, appropriate test parameters need to be set, including test voltage, test frequency, and test time. These parameters need to be set according to the requirements of the tested equipment.

induce

The series resonance withstand voltage test method is an efficient, accurate, and safe testing method suitable for evaluating the insulation performance of equipment in power systems. By correctly setting the parameters of the resonant circuit, selecting appropriate testing equipment and environment, and strictly following operating procedures and safety regulations, the accuracy and safety of the test can be ensured.