Research On Operation Optimization Of Distribution System With Electric Energy Router

The massive integration of renewable energy and electric vehicle(EV)which has increased the uncertainty of “source” and “load” have been posing challenges to the operation of power grid.The vigorous development of electronics technology has provided a powerful means for the control of power systems.The electric energy router(EER)which is based on electronic devices can effectively regulate the power transmission and play the role of power hub.Based on this,this paper presents an operation optimization methodology in distribution system with EER,which combines the conventional operation optimization method.Firstly,this paper builds a three-phase unbalanced power distribution system model that considering renewable energy access and load diversity.The output characteristics of wind and photovoltaic power are given.The load is divided into three kinds of conventional load and three kinds of EV charging load.The EV charging load is calculated by Monte Carlo simulation.Secondly,this paper brings a multi-objective two-level hierarchical operation optimization(TLHOO)approach during a 24-hour period.The multi-objective function includes the active power loss and the voltage deviation.The control variables are the network topology and the power delivered by EER unit(EERU)which including the active power transmitted and the reactive power emitted.The approach includes the first-level optimization and the second-level optimization.The first-level optimization is general adjustment.An adaptive time period division method for 24-hour is proposed.The topology is adjusted at each time period.The second-level optimization is delicate adjustment,it adjusts the delivered active and reactive power of the nodes which connected to the EERU at each time point.Thirdly,the hybrid multi-objective particle swarm optimization(HMOPSO)algorithm is used.The switch state is built as the particle model in the first-level optimization.A novel dynamic inertia weight assignment method is proposed.The delivered power of EERU is modeled as the particle model in the second-level optimization.And to evaluate and select the final solution in the optimal solution set,fuzzy logic algorithm is applied in this process.Finally,the feasibility and effectiveness of this methodology are verified by simulation.