In the power system, lightning impulse voltage and operating impulse voltage are two crucial concepts. They not only affect the safety and reliability of equipment, but also the overall operating efficiency of the power system. In order to effectively reduce the impact of lightning and operating impulse voltage on equipment, engineers need to adjust multiple parameters.
1. Characteristics of lightning impulse voltage
Lightning impulse voltage is an instantaneous high voltage caused by lightning phenomena in nature. This voltage usually has an extremely high amplitude and a fast rise time. The characteristics of lightning impulse voltage mainly include:
Amplitude: The amplitude of lightning impulse voltage is usually between several thousand volts and several million volts, and the specific value depends on the intensity of lightning and the approach distance.
Rise time: The rise time of lightning impulse voltage is usually at the microsecond level, which means that the voltage reaches the peak in a very short time.
Duration: The duration of lightning impulse voltage is relatively short, usually between tens of microseconds and hundreds of microseconds.
Due to these characteristics of lightning impulse voltage, equipment in the power system must have a certain lightning resistance to avoid equipment damage caused by overvoltage. Therefore, during the design and installation process, engineers need to reasonably adjust the insulation level, grounding system and lightning protection measures of the equipment.
2. Key points for adjusting the parameters of switching impulse voltage
Unlike lightning impulse voltage, switching impulse voltage is a transient voltage caused by switch operation, equipment failure or other human factors in the power system. The characteristics of switching impulse voltage include:
Amplitude: The amplitude of the switching impulse voltage is usually smaller than the lightning impulse voltage, but it may still reach several thousand volts.
Rise time: The rise time of the switching impulse voltage is usually longer, which may be between a few milliseconds and hundreds of milliseconds.
Duration: The duration of the switching impulse voltage is relatively long, which may be between hundreds of milliseconds and a few seconds.
In order to effectively deal with the switching impulse voltage, the design of the equipment needs to take into account the frequency of switching operations and possible fault scenarios. Therefore, reasonable adjustment measures include optimizing the insulation design of the equipment and selecting appropriate protection devices.
3. Key parameter adjustment
When adjusting lightning impulse voltage and switching impulse voltage, the following key parameters need special attention:
Insulation level: The insulation level of the equipment is an important factor in resisting impulse voltage. By selecting appropriate insulating materials and increasing the insulation thickness, the impact resistance of the equipment can be improved.
Grounding system: A good grounding system can effectively disperse the lightning impulse voltage and reduce its impact on the equipment. The size of the grounding resistance, the layout of the grounding electrode, and the selection of grounding materials all have a significant impact on the grounding effect.
Protective devices: In the power system, the use of appropriate protective devices (such as lightning arresters, overvoltage protectors, etc.) can effectively suppress the impulse voltage and ensure the safe operation of the equipment.
Selection of cables and wires: The selection of cables and wires will also affect the propagation characteristics of the impulse voltage. The use of appropriate cable specifications and materials can reduce the conduction of the impulse voltage.
4. Regulation in practical applications
In practical applications, the regulation of lightning impulse voltage and operating impulse voltage requires comprehensive consideration of multiple factors. For example, in the design of high-voltage substations, engineers need to formulate corresponding protective measures based on geographical location, climatic conditions, and equipment type. In addition, regular inspection and maintenance of equipment to ensure the effectiveness of insulation performance and grounding systems is also an important measure to reduce the impact of impulse voltage.
5. Future development trends
With the continuous advancement of science and technology, the design and protection measures of power systems are also evolving. The application of new materials, the introduction of intelligent monitoring technology and more refined design concepts have provided new possibilities for improving the power system’s ability to resist impulse voltage. In the future, as the requirements for the safety and reliability of power systems continue to increase, how to more effectively regulate lightning impulse voltage and operating impulse voltage will become an important issue that power engineers need to solve.
The regulation of lightning impulse voltage and operating impulse voltage involves comprehensive consideration of multiple parameters. By optimizing insulation levels, grounding systems, protection devices and cable selection, the impact of impulse voltage on equipment can be effectively reduced, and the safety and stability of power systems can be improved.
Post time: Feb-20-2025