Improved Continuation Power Flow Calculation Method Based on Coordinated Combination of Parameterization

Continuation power flow (CPF) is the most commonly used voltage stability static analysis method, and it consists of four steps: prediction, step-size control, parameterization and correction, among which parameterization is a key factor to ensure the success of continuous power flow calculation. At first, a performance analysis of common parameterization methods is studied, the criterion for judging the merits of the parameterization method is the distance between the predicted point and the exact solution of the CPF. The closer, the faster the correction can be converged. Various parameterization methods varies in merits and demerits in the different regions of the CPF solution curve. Therefore, in order to fully exploit, use and complement the information of each parameterization method, a coordinated combination of parameterization method is proposed. Varies of the parameterization methods are adopted in different regions of PV curve, while also setting parametric switching breakpoints during the process of tracing PV curve, and using the divergence of correction as the combination switching criterion. Finally, applying fixed-step method and classic variable-step method, continuation power flow calculations are carried out respectively with different parameters. Computational analysis of the IEEE 39-bus shows that the proposed coordinated combination parameterization method has significant effectiveness and superiority.