Static voltage stability influence evaluation method of distribution network including electric vehicles based on LHS-PPF

Abstract

The temporal and spatial distribution of electric vehicle charging load (EVCL) is closely related with the drivers’ trip behavior, which has a highly uncertainty. The access of EVCL will increase the risk of safe and stable operation of the distribution network. To evaluate the impact of EVCL access to system’s static voltage stability, we propose a novel probability evaluation method based on the combination of static voltage stability evaluation model and probabilistic power flow (PPF). Firstly, considering steady state operation, dynamic operation and ultimate operation of the distribution network, the three different static voltage stability evaluation models are established respectively. Then, the probabilistic power flow model is adopted to simulate the impact of EVCL on the power flow of the distribution network. To improve the low calculation efficiency of the PPF model based on the Monte Carlo sampling method, the Latin hypercube sampling (LHS) is used. The LHS-PPF model not only ensures calculation accuracy but also improves calculation efficiency. Finally, based on MATLAB 2020a simulation software, the proposed method is programmed in M language. The results show that the access of EVCL will obviously decrease the system anti-interference capability, and increase the risk of the system approaching limit operation state. The case studies verify the correctness and effectiveness of the proposed method.