Calculation of Static Voltage Stability Margin Based on Continuous Power Flow and Improved Differential Evolution Algorithm

Abstract

Abstract With power grid heavy-load operation, and remote transmission distance which leads to voltage collapse, the method that combines continuous power flow (CPF) and improved differential evolution (IDE) algorithm is put forward to calculate a static voltage stability margin. First, we introduce mathematical model and CPF for solving the static voltage stability margin. And then, simulated annealing strategy is brought into differential evolution (DE) algorithm. When temperature is high, it can optimize the combination of control variables, and has the ability of global search. With the temperature decreasing, local search capabilities are enhanced and search speed is accelerated. In the crossover operator of DE algorithm, adaptive crossover probability strategy is introduced. The value of the crossover probability varies with the individual fitness. The individual with high fitness has more opportunities to go into next generation, while others will be kicked out quickly. This method is simple, easy to understand and realize, has fewer controlled parameters, and fast calculation. The correctness and validity of this algorithm can be verified by IEEE14-bus and IEEE30-bus system.