A Comprehensive Approach to Assess Voltage Stability Margin from the Characteristics of Power Transmission Networks

In this paper, the minimum singular value of power-flow Jacobian matrix and P-V curve are computed in order to accommodate the maximum number of power transfers and available active power margin on the transmission networks. Furthermore, the combination of singular vectors and V-Q curves presents a more precision and efficient approach to indicate system weak buses ranking and its reactive power quantitative analysis, and it can detect the robustness of transmission network via classified the vulnerable levels of system buses. As the system vulnerable levels are found, some critical contingencies and load shedding analyses demonstrate the variation of voltage stability margin via modulate power transmission networks. The approaches were test on Taiwan power system, a stressed, isolated and longitudinal power system, the difference and effect of voltage stability margin and system vulnerable levels were pointed out