Voltage Control and Dynamic Performance of Power Transmission Using Static VAR.

The power demand, in the recent years, has increased substantially while the expansion of power generation and transmission has been severely limited due to environmental restrictions and limited resources. As aneffect, some transmission lines are heavily loaded and the system stability and voltage becomes a limiting factor for power transfer. Flexible AC transmission systems (FACTS) controllers have been mainly used for solving various power system steady state control problems. However, studies reveal that FACTS controllers could be employed to enhance voltage profile in the network in addition to their function of power flow control in the network. This paper presents how static var compensator (SVC) can be utilized to control transmission system dynamic performance for system disturbance and effectively regulate system voltage. Static var compensator (SVC) is basically a shunt connected static var generator whose output is adjusted to exchange capacitive or inductive current so as to maintain or control specific power variables, typically, the control variable is the system bus voltage. Voltage control and the increase in system load abilityarethe main applications of SVC in this paper. Firstly, to design a controller for SVC devices on a transmission line, a single machine infinite bus (SMIB) is modeled. A state space model is developed in the MATLAB/SIMULINK to show the improvement in the dynamic performance of the system.