The operating impuse test is a test method used to evaluate the insulation performance of electrical equipment under operating overvoltage conditions. It simulates overvoltages generated by switching operations, failures, or other transient processes in a power system, ensuring that the equipment can withstand such shocks in actual operation. The following are the main features of the operational impact test:
1. Waveform characteristics
Standard waveform: The 250/2500μs waveform (wavefront time 250μs, half-peak time 2500μs) is usually used for the operating shock test to simulate the typical characteristics of the operating overvoltage.
Long duration: Compared to the lightning shock test (1.2/50μs), the waveform of the operating shock is longer in duration and more energetic.
2. Test purpose
Assess insulation performance: Test the insulation strength of equipment under operating overvoltage conditions to ensure that it does not break down or flash over.
Simulate actual working conditions: simulate the overvoltage generated by transient processes such as switching operation and fault removal in the power system to verify the reliability of the equipment.
3. Test voltage
Voltage level: The voltage of the operation impulse test is usually 2-3 times the rated voltage of the equipment, and the specific value is determined according to the type of equipment and standard requirements.
Polarity selection: Tests typically include both positive and negative polarity shocks to fully assess insulation performance.
4. Test equipment
Impulse voltage generator: Generates an operating impulse waveform.
Voltage divider and oscilloscope: Used to measure and record voltage waveform and device response.
Test objects: such as transformers, cables, circuit breakers, and other power equipment.
5. Test standards
Operational impact tests should comply with relevant international and national standards, such as:
IEC 60060-1: High voltage test techniques.
GB/T 16927.1: China's national standard, high voltage test technology.
IEEE C62.41: Definition and Application of operational shock waveforms.
6. Analysis of test results
Passed standard: the equipment did not break down or flash over in the test, and the insulation performance met the requirements.
Failure condition: If the equipment has a breakdown or insulation damage, it is necessary to analyze the cause and improve the design.