Static Voltage Assessment based on Electro-thermal coupling V-Q Sensitivity Analysis

Abstract

Although the traditional V-Q sensitivity can quickly determine the stability of the system bus voltage, its mathematical model only considers the electrical model of the line and ignores the electro-thermal coupling relationship of the line under actual conditions. Therefore, the use of traditional model calculation results as a reference for the actual bus voltage stability judgment has a large deviation. With this as a background, this paper establishes an electro-thermal coupled power flow model, which is based on the IEEE standard heat balance equation and regards the transmission line resistance as the state variable of the power flow. Then, based on the expansion of the Jacobian matrix in the improved power flow model, a V-Q sensitivity analysis method considering the electro-thermal coupling is proposed, and the calculation example is compared and analyzed with the traditional model in different seasons. The results show that the traditional model ignores the influence of the line temperature and resistance due to the electric and heat balance, which will introduce certain errors in the calculation results for different seasons.