A New On-line Power Flow Calculation Method with Computation Loads Separation Technique in DC Power Systems

Abstract

The speed of one-time power flow calculation is hard to be further improved with satisfied accuracy and stability after decades of researches. However, the improvement on many-times calculation speed may be possible and is important for practical application. This paper proposes a novel method which can dramatically improve the many-times calculation speed of power flow without sacrifice of accuracy, convergence and stability in DC power systems. To achieve the purpose, this paper adopts a novel basic technique to separate the computation loads of grid topology analysis and bus types analysis from power flow equations. The technique is based on the analysis of linear relationships-based nonlinear problems and strict mathematical derivations. Combined with the basic technique, a correctness method is also proposed to deal with the specific nonlinear factors in power flow calculation. Thus, a complete novel power flow calculation method is proposed and the detailed mathematical derivation is presented. With the novel ant lion optimizer, the proper DC test systems are constructed. Compared with classical Newton–Raphson method, the proposed method is more stable and the initial values requirement is lower. At last, the numerical verification validates that the speed of the proposed method can be more than 10 times faster than Newton–Raphson method without the sacrifice of other performance.