Coordinated optimal dispatch of photovoltaic units with updated power electronic transformer

The stochastic variation of photovoltaic (PV) generation units in the distribution grid has increased complexity of the optimal dispatch. Updated power electronics devices such as power electronics transformer (PET) are installed to improve the energy efficiency of DC power appliances and the control flexibility. The synergy effects of optimal dispatch of photovoltaic units and updated PET operation are analyzed in this paper. A two-stage optimization model is established to search for the best configuration and operation of distribution grid with updated PET feeders and photovoltaic inverters. The optimal configuration of PETs is given in the upper stage and given to the lower stage as input parameters to regulate the active and reactive power of photovoltaic inverters associated with operation of feeders updated with PETs. The coordinated optimization between updated PETs and photovoltaic generation units is developed to minimize the operation cost and total power losses in the distribution grid. NSGA-II algorithm is adopted to solve the proposed multi-objective optimization with constraints from both reliable operation of power system and power electronics devices. Comparisons between the simulation results with and without the proposed coordinated optimization for PETs and PVs valid the effectiveness of two-stage optimization model. The operation cost and power losses are reduced while avoiding the power curtailment of PV units by optimally configuring and regulating the power electronic devices including the PETs and inverters of PVs in the test distribution network.