A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering

Thesis (M.Eng.) - Asian Institute of Technology, 2009

Voltage instability has been a primary concern in power system both at planning as well as operation stage, since there have been several major power failure throughout the world associated with this phenomenon. Thus voltage stability analysis is essential for secure power system operation. This thesis proposes a various methods for the enhancement of static voltage stability margin of the Bhutan power system network. The objective of this study is to enhance voltage stability and loadibility based on static analysis. The proposed approach is based on the comparison of installing Shunt capacitor, SVC installation and East West interconnection to increase the static voltage stability margin of Bhutan power system capability. The continuation power flow method is used to identify the proper location and size of the compensation devices in order to enhance the static voltage stability margin. Five different scenarios are considered in this: 1) SVC installed at the weakest bus of the intact system 2) Shunt Capacitor installed at the weakest bus of the intact system 3) East-West Interconnection. 4) SVC installed at the weakest bus of the interconnected system. 5) Shunt capacitor installed at the weakest bus of the interconnected system. IEEE 9-bus system was also simulated to test and compare the increasing loadibility. Results from this work shows that these methods helps enhance the static voltage stability and loadibility margin of Bhutan power system network