Short Answer:

Capacitor banks in power systems provide reactive power compensation to improve power factor and voltage stability. They supply leading reactive power, reducing the burden on generators and transformers.

By installing capacitor banks, power losses decrease, system efficiency improves, and electricity costs are lowered, making them essential for reliable and economical power delivery.

Detailed Explanation:

Role of capacitor banks in power systems

Introduction

Capacitor banks are groups of capacitors connected together in power systems to supply reactive power locally. Their main function is to compensate for the lagging reactive power caused by inductive loads such as motors, transformers, and fluorescent lighting.

Functions of Capacitor Banks

1. Power Factor Improvement
   • Inductive loads cause the current to lag voltage, leading to low power factor.
   • Capacitor banks supply leading reactive power, offsetting the lagging reactive power.
   • This raises the overall power factor closer to unity, improving efficiency.
2. Voltage Support and Regulation
   • By supplying reactive power locally, capacitor banks help maintain voltage levels within permissible limits.
   • This reduces voltage drops along transmission and distribution lines.
3. Reduction of Transmission Losses
   • Improved power factor lowers current in the system.
   • Reduced current decreases I²R losses in conductors, improving energy efficiency.
4. Increased System Capacity
   • With better voltage and power factor, the system can carry more load without upgrades.
   • Delays the need for costly infrastructure expansion.
5. Cost Savings
   • Reduces electricity bills by avoiding power factor penalties.
   • Minimizes energy losses, lowering operational costs.

Types of Capacitor Banks

• Fixed Capacitor Banks: Provide constant reactive power compensation.
• Switched Capacitor Banks: Can be turned on/off automatically based on load conditions for optimal compensation.
• Detuned Capacitor Banks: Used to prevent resonance and harmonics.

Installation Considerations

• Capacitor banks are installed near large inductive loads or at substations.
• Proper sizing and coordination with system protection are critical to avoid overcompensation and resonance.
• Regular maintenance ensures effective operation.

Conclusion

Capacitor banks play a vital role in power systems by improving power factor, supporting voltage stability, reducing losses, and enhancing system capacity. Their use leads to efficient, reliable, and cost-effective electricity supply.