Monitoring Power Transfer Capability of EHV AC Lines under Lightly Loaded Conditions using Compensation

Abstract

Abstract The increase in demand of electrical power has elevated the concern about security and reliability of the interconnected systems of Extra High Voltage (EHV) systems. These increases are brought about by environmental and an economic pressure which has led to an increased complexity in the system. Power-frequency over-voltages and obtaining of the maximum power transfer limit are two major concerns of interconnected systems using long EHV links. It has been proven that by using the series and shunt compensations are the best available methods because the transmission distance can be reduced artificially and hence more power can be transferred. The effect of shunt compensation on an EHV long transmission line under lightly loaded conditions is studied in this thesis. This is achieved by developing a MATLAB program to calculate the required compensations and by using ETAP power station to conduct a power system analysis on test case system i.e. IEEE 14 bus system to maintain the load voltage profile over the link and determine the maximum power transfer limit that may be transmitted under the influence of various factors such as the line length, load power factor and the degree of compensation. The results obtained have shown that by controlling the shunt compensation, it will improve remarkably on the transmission capability.