Sensitivity matrices for reactive power dispatch and voltage control of large-scale power systems

Abstract

In large-scale power systems, generating plants provide energy to consumers through exceedingly flexible and dynamic networks of transmission lines. The delivered electrical energy is maintained in high quality and the voltage profile is kept within acceptable limits by the utilization of control devices scattered in key locations over the power grid. Thus, one of the most important problem facing power utilities is how to coordinate the reactive power compensation devices to maintain acceptable bus voltage profile while minimizing operational costs and assuring system stability in the presence of disturbances. The work presented in this paper derives the sensitivity matrices of the load-bus (or PQ-bus) voltages due to differential change in compensator devices in a systematic approach over the complex field. A novel vectorized modeling and analysis of power system is introduced with necessary theorems and lemmas. The derived sensitivity matrices are expressed in terms of the system admittance matrix and the phasor voltage profile. Vector modeling and analysis of power system is also introduced. Based upon the sensitivity matrices, priority lists of control devices are established for different contingencies. The priority lists are utilized to determine a control action to alleviate the voltage problem. Finally, the standard IEEE 14-bus is used as a test system to demonstrate the effectiveness of the proposed work.