Research On Topology And Control Strategy Of Electric Energy Router At The End Of Distribution Network

As a new energy network architecture,the Energy Internet,which is composed of traditional power grid,new energy equipment and energy storage devices,can balance the contradictions among the three,such as the difficulty of new energy consumption and the two-way orderly flow of power flow.Therefore,the Energy Internet will become the core architecture of modern power system construction.In particular,the Electric Energy Router has the advantage of active regulation of power flow,which can realize the energy routing function between traditional power grids,new energy equipment and energy storage devices,and will surely become a key core device in the future Energy Internet.In view of the current situation that the existing research on Electric Energy Router is concentrated on the Electric Energy Router of the backbone network,but lack of research on the Electric Energy Router of the distribution network,this article is based on the green reform of urban industrial parks and the transformation of rural power distribution networks in my country,and deeply studies the working mechanism,topology,parameter design method,control strategy and software and hardware system of the Electric Energy Router at the end of the distribution network.The main contents of this paper are as follows:（1）It introduces the definition and basic structure of the Energy Internet in detail,summarizes the characteristics of the current distribution network in urban industrial parks and rural areas in my country,expounds the definition and basic characteristics of Electric Energy Routers,and analyzes the current research status of Electric Energy Router topology and control strategies at home and abroad.Clarified the major theoretical and practical significance of the research of this subject.（2）The architecture of the new Electric Energy Router is proposed,and the working mechanism of the new Electric Energy Router is analyzed according to the internal power balance relationship of the system from the two perspectives of whether it is connected to the electric vehicle;the specific topology of each module of the main circuit of the Electric Energy Router is proposed,and its working principle is studied;the parameter design method of each power component of the main circuit is discussed,and the parameter calculation and component selection are carried out.（3）According to the function of each module and different working conditions,the control strategy of each sub-module and the overall coordinated control strategy of the system are proposed,and the stability analysis and simulation verification are carried out.Specifically,the photovoltaic module adopts a control strategy that combines MPPT and voltage and current double loops;the charging and discharging process of the energy storage module adopts a constant power single loop control strategy;the charging pile module adopts a constant power or constant voltage single loop control strategy according to the charging state of the electric vehicle;The bidirectional converter module adopts a voltage and current dual-loop control strategy,which realizes the active interaction between the system and the grid while using the remaining capacity of the module to perform reactive power compensation for the local AC side load;The overall system adopts a coordinated control strategy based on the difference between the power emitted by the photovoltaic module and the power absorbed by the charging pile module as the basis for determining the operation mode of the energy storage and bidirectional converter modules.（4）According to the Electric Energy Router topology and control strategy,the main circuit of the device and the hardware circuit and software program of the device control system with TMS320F2812 as the core are designed.The control system hardware circuit specifically includes DSP and its peripheral circuits,auxiliary power supply module,external expansion storage module,and detection and drive module;the control system software program specifically includes the main program and the interrupt subroutine composed of AD sampling and PWM programs.On the basis of theoretical analysis and simulation verification,a 10 k VA/380 V prototype was built for simulation experiment verification.The experimental results prove that the parameter design method and system control strategy proposed in this paper are reasonable and feasible,and the system can operate stably.