Research On Plug-and-Play Technology And Terminal For Client-side Energy Interconnection

At present,with the development of renewable energy generation and distributed energy storage system,the boundary of supply and demand of energy industry is blurred,and clients have been transformed from consumer of electricity to prosumer.However,due to the intermittence and randomness of renewable energy,its large-scale parallel in the grid will have a negative effect for the normal operation.Relevant studies show that energy interconnection of demand-side can effectively restrain the grid-connected power of renewable energy to match the expected value and reduce the peak-valley difference of load.This thesis relies on the State Grid Corporation's scientific and technological project named "Client Side Energy Interconnection Oriented Technology Research of Intelligent Flexible Access to Electricity and Interactive Services(YDB17201700249)".It builds the home energy management system on the client-side and develops the plug-and-play terminal to achieve the users' demand response service.The main contents of the thesis are as follows:Firstly,this thesis researches the main functions of home energy management system and establishes four typical mathematical models of household energy supply and consumption devices,which include photovoltaic power generation system,battery energy storage system,electric water heater and electric vehicle.Taking four kinds of typical devices as the object,this thesis utilizes particle swarm optimization(PSO)algorithm to obtain the day-ahead power consumptions scheme.Based on the model predictive control(MPC)theory,when the actual photovoltaic output deviates from the previous prediction,it takes the charge and discharge power of battery as the control variable,so that the controlled variable can track the forecast as much as possible.The results show that electricity consumption habit and the interconnection of intelligent devices can decrease the operation cost of users.The users' participation in demand response service can alleviate the power supply pressure during the peak period of power consumption.At the same time,the excess power can also be fed back to the grid for more economic benefits.Secondly,as the users' participation in the demand response service needs to establish an interactive channel between the grid side and the client side,this thesis analyzes the functional positioning of the plug-and-play terminal.As a bridge between external devices and power grid platform,the terminal mainly implements the functions of device protocol identification,protocol library establishment,and demand response command management and execution.In view of this,three key plug-and-play technologies are proposed in this thesis.It includes communication protocol automatic identification technology,real-time monitoring technology based on HeartBeat packet and design method of extensible electronic data sheet based on XML.Finally,this thesis completes the hardware design and development for software of the plug-and-play terminal,and carries out verification test.In the aspect of hardware,the thesis designs the system structure diagram of terminal,which adopts the concept of modularization and embedded system.The function of modules is independent,has good expansibility,and is convenient for later maintenance.In software aspect,it researches the application layer of the system,creates the communication thread by using connection-oriented socket programning and explores the upstream communication,downstream communication and human-computer interaction modules of the system to accomplish the two-way interaction between the external devices and the management platform.Through research and comparison,electric vehicle charging pile,electric water heater and photovoltaic inverter are used as test objects.Access to the laboratory of supply and demand interactive intelligent energy management platform of China Electric Power Research Institute Co.Ltd,this thesis verifies that the power grid management platform can accomplish the client-side demand response service through the terminal,and proves the effectiveness and feasibility of the system.