Operational impulse test and lightning shock test are two common high voltage test methods, which are mainly used to evaluate the insulation performance of electrical equipment. Although they all involve transient overvoltages, there are significant differences in waveform, purpose and application scenarios. Here are the main differences;
1. Different waveforms
Operational impulse test:
Waveform: 250/2500μs (wavefront time 250μs, half peak time 2500μs).
Features: The waveform duration is long, the energy is large, and the simulation operation overvoltage.
Lightning impulse test:
Waveform: 1.2/50μs (wavefront time 1.2μs, half peak time 50μs).
Features: Waveform duration is short, steep, and peak high, simulating lightning overvoltage.
2. Different test purposes
Operational impulse test:
Simulate operating overvoltage in power system, such as switching operation, fault cutting and other transient processes.
Evaluate the insulation performance of equipment under operating overvoltage conditions.
Lightning impulse test:
Simulates the transient overvoltage generated when lightning strikes equipment or lines.
Evaluate the insulation performance of equipment under lightning overvoltage conditions.
3. Different application scenarios
Operational impulse test:
Mainly used in power system transformers, circuit breakers, cables, and other equipment.
It is particularly suitable for evaluating the reliability of equipment under operating overvoltage conditions.
Lightning impulse test:
Applicable to all electrical equipment that may be hit by lightning, such as transmission lines, substation equipment, etc.
Pay special attention to the insulation strength of the equipment under a lightning environment.
4. The test voltage is different
Operational impulse test:
The test voltage is usually 2-3 times the rated voltage of the equipment, and the specific value is determined according to the type of equipment and standards.
Lightning impulse test:
The test voltage is high, usually several times the rated voltage of the equipment, and the specific value is determined according to the lightning protection grade and standard.
5. Different test standards
Operational impulse test:
Comply with standards such as IEC 60060-1, GB/T 16927.1, etc.
Focus on the simulation and evaluation of operating overvoltages.
Lightning impulse test:
Comply with standards such as IEC 60060-1, GB/T 16927.1, IEEE C62.41, etc.
The simulation and evaluation of lightning overvoltage are emphasized.