Reactive Power Control for Power System Stability

Abstract

ABSTRACT newline newline newline newline newlineGenerally, electrical power systems being a highly complex system is facing more difficult and challenging problems in managing and maintaining its stability. The power system management is becoming difficult because power systems are operated closer to security limits, environmental constraints restrict the expansion of transmission network and increase in need of long distance power transfers. Above all these, voltage instability has become an important concern in power systems. Many blackouts have been reported, where the reason has been voltage instability. Static Synchronous Compensator (STATCOM) which is a Flexible Alternating Current Transmission System (FACTS) device can be employed. The major objective functions of voltage regulation are: (i) Voltage level on the terminals of entire equipment should be reserved within the boundary (ii) Equipment failure and malfunction should be minimized. To achieve the reliable and efficient operation, the voltage and reactive power control should be designed. newlineSTATCOM, a shunt connected device of FACTS family in power electronics has the capability to supply the capacitive reactive power in faulty condition. It is due to the high capacitive reactive power produced through a STATCOM reduces linearly by means of system voltage, whereas the Static Var Compensator is proportional to the square of voltage. The major role of STATCOM (static synchronous compensator) is regulating the voltages in interconnecting buses within the limits and provides the dynamic reactive power compensation. Also STATCOM combined with Proportional Integral (PI) controllers are designed for satisfactory dynamic response and the control gains were normally tuned for trial-and-error method. This research work constitutes with the study of developing a control over the STATCOM controller for regulating the voltage in power transmission systems. So the traditional PI control is applied on STATCOM voltage regulation. The performance of PI controlled STATCOM is made more effective a