Probabilistic evaluation method of voltage quality for urban power network considering vehicle to grid

Conventional power quality evaluation methods based on deterministic power flow and static probability power flow fail to consider time-variability of uncertain factors in urban power network. Therefore, dynamic probability power flow is applied to evaluate voltage quality for urban power network considering vehicle to grid (V2G). Dynamic probability models of basic load and electric vehicle's power are built. Probabilistic distributions of node voltage in urban power network are obtained using dynamic probability power flow based on cumulant method. And then daily voltage qualified rate of urban power network is acquired. Finally, voltage quality for urban network considering V2G is evaluated. Simulation results show that electric vehicles under V2G mode can result in decline of voltage quality of urban power network. But voltage quality of urban network under V2G mode is still superior to that under uncoordinated charging mode. Evaluation results have important reference values for formulating V2G control strategy and planning urban power network in future. ©, 2015, Power System Technology Press. All right reserved.