Voltage Profile Improvement and Loss Reduction Using Optimal Location of Shunt Connected Facts Devices

Abstract

Due to the voltage instability, the power system which is highly loaded and frequently changing, is highly affected. As the demand of power is increasing and due to connection of large power systems, the operation and planning has become more and more complex and difficult. This has added to the power system insecurity. The operating methods, environments are exposing the power system to instabilities. The occurrence blackouts in the power system are mainly due to the condition of voltage instability. Due to increased power demand the voltage profile is also compromised. The buses voltages might not be according to the desired levels and hence voltage collapse may occur. Undesired voltage profile can also cause heavy losses in the transmission lines leading to uneconomical power system operation. The power system security are improved by considering desired measures and also it can improve the voltage stability margins. FACTS devices have become essential for improving the stability of voltage, maintain the voltage profile and also reduce the losses present in transmission line. FACTS devices are flexible and their control characteristics are fast. Hence, they can be used for controlling magnitude of voltage. These can also be utilized to regulate the reactive and active power. Finding an optimal location for placing the FACTS device is also essential for the best results. In this thesis IEEE 14 and IEEE 30 bus systems are taken. Load flow analysis is carried by using Newton Raphson load flow method. Fast Voltage Stability Index is used to find the weakest bus in IEEE14 and 30 bus systems. SVC and STATCOM are placed at these weakest buses by incorporating in load flow program compiled and executed in MATLAB R2014a. The voltage profile and transmission line losses are compared with and without using the FACTS devices.