What Are The Benefits Of Installing Capacitors?

Power capacitors provide several benefits to power systems. Among these include power factor correction, system voltage support, increased system capacity, reduction of power system losses, reactive power support, and power oscillation damping.

Power Factor Correction.
In general, the efficiency of power generation, transmission, and distribution equipment is improved when it is operated near unity power factor. The least expensive way to achieve near unity power factor is with the application of capacitors.

Capacitors provide a static source of leading reactive current and can be installed close to the load. Thus, the maximum efficiency may be realized by reducing the magnetizing (lagging) current requirements throughout the system.

System Voltage Support.
Power systems are predominately inductive in nature and during peak load conditions or during system contingencies there can be a significant voltage drop between the voltage source and the load. Application of capacitors to a power system results in a voltage increase back to the voltage source, and also past the application point of the capacitors in a radial system.

The actual percentage increase of the system voltage is dependent upon the inductive reactance of the system at the point of application of the capacitors. The short-circuit impedance at that point is approximately the same as the inductive reactance; therefore, the 3-phase short-circuit current at that location can be used to determine the approximate voltage rise.

Increased System Capacity.
The application of shunt or series capacitors can affect the power system capacity. Application of shunt capacitors reduces the inductive reactive current on the power system, and thus reduces the system kVA loading. This can have the effect of increasing system to serve additional load.

Series capacitors are typically used to increase the power carrying capability of transmission lines. Series capacitors insert a voltage in series with the transmission line that is opposite in polarity to the voltage drop across the line, which decreases the apparent reactance and increases the power transfer capability of the line.

Power System Loss Reduction.
The installation of capacitors can reduce the current flow in a power system. Since losses are proportional to the square of the current, a reduction in current will lead to reduced system losses.

Reactive Power Support.
Capacitors can help support steady-state stability limits and reactive power requirements at generators.

Power Oscillation Damping.
Controlled series capacitors can provide an active damping for power oscillations that many large power systems experience. They can also provide support after significant disturbances to the power system and allow the system to remain in synchronous operation.

No comments:

Post a Comment