Load flow control and analytical assessment of voltage stability index using thyristor controlled series capacitor (TCSC)
Date
2014-04
Authors
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Journal ISSN
Volume Title
Publisher
U. P.
Abstract
- Voltage stability problem has become one of the major concerns in the operation of power system in recent years. The reason is that power systems all over the globe are being operated with reduced margins because of the exponentially growing demands and the associated stress on the power transmission resources aggravated by a general reluctance to invest in improvement of the electric grid infrastructure. Moreover, voltage instability has been responsible for severe network collapses world-wide and subsequently, the possible threat of voltage instability is becoming more pronounced in power utilities. In order to avoid the voltage collapse, this paper presents maximum loadability identification of a load bus in a power transmission network which is achieved by performing voltage stability study by utilizing Fast Voltage Stability Index (FVSI) as an indicator of the maximum loadability termed as Qmax. In this technique, reactive power loading will be increased gradually at particular load bus until the FVSI reaches close to unity. Therefore, a critical value of FVSI was set as the maximum loadability point. This value ensures the system from entering voltage-collapse region. The main purpose in the maximum loadability assessment is to plan for the maximum allowable load value to avoid voltagecollapse; which is important in power system planning risk assessment index. In order to improve the system stability, Thyristor Controlled Series Capacitor (TCSC) is installed in the most severe line, which is identified from the line stability index values of all lines in a system. TCSC is a series compensated device used for voltage
stability enhancement, which is to be connected in series with transmission line. It can control the transmission line impedance to improve the line transfer capability and to regulate the receiving end bus voltage. This proposed
technique was applied to solve real problems in a 14 bus power grid using Power flow analysis. Power flow is very necessary for planning, operation, economic scheduling and exchange of power between utilities. Newton
Raphson iterative algorithm is used for solving the power flow problems due to its ability to converge very fast with small number of iteration. Simulation of power flow solutions with and without TCSC was done using MATLAB 7.5 program. The result shows that the application of TCSC improved the voltage profile of the system and furtherly enhanced the power flow.
Description
This article contains figures and tables
Keywords
TCSC, FACTS, line flow index, FVSI, criticality index, load flow, matlab, Department of Electrical/Electronic Engineering
Citation
Akwukwaegbu, I. O. & Okwe, G. I. (2014). Load flow control and analytical assessment of voltage stability index using thyristor controlled series capacitor (TCSC). International Journal of Engineering Research and Development, 4(10), 07-18