SMD Aluminum Electrolytic Capacitor

Photocoupler

Power capacitors are essential components in electrical systems, primarily used to compensate for reactive power and improve the power factor. In most power distribution systems, the load is inductive, which means the current lags behind the voltage by 90 degrees. When a power capacitor is connected to the system, it generates a leading current that is 90 degrees ahead of the voltage. This opposing current helps cancel out part of the inductive current, effectively reducing the overall reactive power demand.

When operating power capacitors, safety and efficiency should be prioritized. It's crucial to operate them at their rated voltage, not exceeding 1.05 times the rated value. However, they can tolerate up to 1.1 times the rated voltage for a limited period—typically no more than one hour. If the voltage exceeds this limit, the capacitor should be immediately disconnected to prevent damage. High voltage can lead to overheating or internal failure of the capacitor components.

Over-compensation or reactive power reversal after equipment is turned off can also cause issues. Therefore, it's important to manage the system carefully. The ambient temperature for normal operation should range between -20°C and +45°C. Extreme temperatures can lead to bulging or oil leakage, so it's important to maintain proper environmental conditions. Additionally, the indoor humidity should not exceed 80% to avoid moisture-related damage.

Maintenance plays a key role in ensuring the long-term performance and reliability of power capacitors. Regular inspections and proper care can significantly extend their service life.

First, a visual inspection of the capacitor should be conducted regularly. Look for signs of oil leakage, swelling, cracks, or overheated terminals. Any of these issues indicate a potential problem, and the capacitor should be taken out of service immediately to prevent accidents.

Second, monitoring the voltage during operation is important. Fluctuations in the power supply can affect the capacitor’s performance. To ensure safe operation, automatic switching devices are recommended. If automatic control fails, manual intervention may be necessary, with operators adjusting based on the load to avoid overcompensation or reactive power reversal.

Finally, checking the current is essential for maintaining the capacitor’s longevity. Power capacitors should ideally operate at their rated current, but they can handle up to 1.3 times the rated current for short periods. Exceeding this limit can result in overheating or even burning out the capacitor. Monitoring the current ensures the capacitor operates within safe limits.

In summary, power capacitors are vital for improving energy efficiency and system stability. Proper installation, operation, and maintenance are essential to maximize their lifespan and ensure safe performance in various applications.