Lightning impulse withstand voltage test is a test method used to evaluate the insulation performance of electrical equipment under high voltage and short pulse conditions. It simulates the impact of lightning shock on the equipment to ensure that the equipment can operate safely under lightning or other transient overvoltage conditions.
1. Test purpose
Verify insulation strength: Test the insulation performance of equipment under high voltage shock to ensure that it can withstand lightning or other transient overvoltages.
Evaluate the equipment's reliability: detect the equipment's potential insulation defects through tests to avoid faults in actual operation.
Meet the standard requirements: meet the international and national standards (such as IEC, GB, etc.) for electrical equipment insulation performance test requirements.
2. Test principle
The lightning impulse withstand voltage test is applied to the insulated parts of the equipment by generating a transient high-voltage pulse (usually 1.2/50μs waveform) that simulates the lightning wave. Specific steps include below;
Waveform generation: Use an impulse voltage generator to produce standard lightning impulse waveform.
Voltage application: High voltage pulses are applied to the insulated part of the device.
Monitoring record: Observe whether the equipment has a breakdown or flashover, and record the test data.
3. Test type
Standard lightning shock test: 1.2/50μs waveform is used to simulate the typical characteristics of lightning shock.
Operating shock test: Simulate operating overvoltage, typically with a waveform of 250/2500μs.
Polarity impact test: Positive and negative impact voltages are applied to evaluate the insulation performance comprehensively.
4. Test equipment
Impulse voltage generator: Generates high voltage pulses.
Voltage divider: Measures the applied voltage value.
Oscilloscope: Record voltage waveform and device response.
Test objects: such as transformers, cables, switchgear, and other electrical equipment.
5. Test standards
The lightning impulse withstand voltage test shall 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 lightning 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.