The introduction of Static var compensator

Static Var Compensator (SVC) is a device that improves the power system's stability and reliability by controlling the reactive power. In this article, we will discuss the introduction of SVC, its working principle, and benefits.

Introduction:

The demand for energy has increased significantly in recent years, leading to an increase in power system complexity. The power system must maintain the voltage and frequency within acceptable limits to ensure safe and reliable operation. Reactive power plays a crucial role in maintaining these parameters. Reactive power is the component of the electrical current that does not contribute to the active power flow but maintains the voltage level. Reactive power control is essential to ensure stable and reliable power supply to consumers.

Static Var Compensator (SVC):

Static Var Compensator (SVC) is a power electronics-based device that controls the reactive power compensation. It is a shunt-connected device that injects capacitive or inductive reactive power into the system to maintain voltage stability. SVC can provide fast reactive power compensation compared to conventional reactive power compensation devices such as capacitor banks or reactors.

Working Principle:

SVC consists of a three-phase thyristor-controlled reactor (TCR) and a three-phase thyristor-switched capacitor (TSC). The TCR and TSC are connected in parallel, and their output is injected into the system through a coupling transformer. The TCR provides continuous reactive power compensation, while the TSC provides quick reactive power compensation. The combination of TCR and TSC can provide a wide range of reactive power compensation from inductive to capacitive.

The SVC controller senses the system voltage and current and adjusts the TCR and TSC firing angle to provide the required reactive power. When the system voltage drops, the SVC increases the reactive power injection by reducing the TCR firing angle or increasing the TSC capacitance. Similarly, when the system voltage rises, the SVC decreases the reactive power injection by increasing the TCR firing angle or reducing the TSC capacitance.

Benefits of SVC:

SVC offers several benefits to the power system, including:

Voltage Stability: SVC can maintain the voltage stability of the system by injecting reactive power into the system when the voltage drops.

Power Quality Improvement: SVC can improve power quality by reducing voltage flicker and harmonics.

Increased Transmission Capacity: SVC can increase the transmission capacity of the system by reducing the voltage drop and line losses.

Fast Response: SVC can provide fast reactive power compensation compared to conventional devices, improving the system's dynamic response.

Reduced Capital Cost: SVC can reduce the capital cost of the power system by eliminating the need for additional transmission lines or new power plants.

Conclusion:

Static Var Compensator (SVC) is a power electronics-based device that controls the reactive power compensation in the power system. It offers several benefits, including voltage stability, power quality improvement, increased transmission capacity, fast response, and reduced capital cost. SVC plays a crucial role in ensuring stable and reliable power supply to consumers in modern power systems.