Voltage Stability Margin Identification Using Local Measurements And Linear Kalman Filter

Abstract

Voltage stability investigation is of a great importance for long-term electric load expansion as well as power system operation. This paper presents a new algorithm for identification of voltage instability in a specified load bus in a power system. The proposed algorithm is based on the linear Kalman filtering algorithm and the maximum power transfer principle. The proposed technique is used to identify Thevenin's equivalent circuit at a bus for different loading conditions, either when the total system loads change at the same rate (long-term voltage stability problem) or when a load on a certain bus changes. The proposed algorithm uses the real measurements at the bus in question to calculate the load impedance. These measurements are the load voltage and current. Thus, it can be implemented on-line on the control centers to investigate the voltage stability. The proposed algorithm is implemented to the standard IEEE 30-bus system.