Online Preventive Control Method for Static Voltage Stability of Large Power Grids

The real-time preventive control is particularly critical because the integration of renewable energy aggravates the random fluctuation of large power grid operating state. An online preventive control optimization method for static voltage stability is proposed based on the Thevenin equivalent parameter identification. According to the definition of the stability margin, its quantitative relationship with the control variable is derived to meet the real-time and reliability requirements of online applications. The preventive control optimization model is constructed to minimize control cost and consider voltage stability margin and operation constraints under multiple critical contingencies. The generator terminal voltage and shunt capacitor in this paper are taken as continuous and discrete control variables respectively. The derived analytical relationship between stability margin and control variable is linearized to form linear security constraints, and the optimization model is transformed into a mixed-integer linear programming problem, which can be solved by CPLEX quickly and reliably. The accuracy and rapidity of the proposed method are verified on several test systems.