Design Of A Microgrid Monitoring System Based On IEC 61850

Electricity is an important energy source for the development of our national economy.Thermal power generation is the main way of generating electricity in China which consumes resources and pollutes the environment seriously.In addition,large-capacity centralized power generation and long-distance high-voltage transmission of the interconnected large power grid has the problems on high cost operating,difficult running and weak adjusting.However,the microgrid technology,which generates distributed power mainly by wind energy,light energy or geothermal energy and so on,including energy-storage equipments,loads and control devices,can save energy,protect the environment,reduce the cost of power generation and meet the demand of intelligent power supply.As we all know,IEC 61850 standard as a microgrid communication standard,can achieve interoperability between different devices made by different factories,and can achieve information sharing.This paper studies a microgrid monitoring system based on IEC 61850 standard to achieve real-time integrated monitoring of distributed generation,storage and load status.Firstly,the whole structure of the three-phase AC(Alternating Current)microgrid system is designed:the underlying microgrid hardware devices and the upper monitoring system are connected by one central controller.Then this paper introduces hierarchical communication structure of the microgrid system,which is divided into dispatch management layer,centralized control layer and local control layer.Among them,MMS + TCP + Ethernet communication architecture is adopted in dispatch management layer.The functional requirements of this microgrid monitoring system is to design a remote Web monitoring system with B/S(Browser/Server)mode based on IEC 61850 MMS(Manufacture Message Specification)service.And then this paper elaborates the main communication technologies the system used and two Java middlewares:a UART Ethernet middleware and a SC AD A(Supervisory Control and Data Acquisition)system middleware,which communicates with the MMS Server and the underlying central controller.Secondly,the paper uses IEC 61850 standard to carry out object-oriented hierarchical modeling about the microgrid system,and the central controller which is responsible for the measurement and control is modeled as an IED(Intelligent Electronic Device).In order to complete the modeling and use the substation configuration description language SCL(Substation Configuration description Language)to form the ICD(IED Capability Description)configuration file,this paper uses the modeling thinking of decomposition step by step firstly,and then combining with each other:determining the logical nodes and data firstly,then building logical devices,and building the server at last.This design uses OpenIEC61850 open source code library to support the entire running of the IEC 61850 and MMS service program.The OpenIEC61850 library is written in Java,so object-oriented language is more in line with object-oriented modeling features of IEC 61850.Besides,Java has the advantage of platform independence,so that the library can run on Windows,Linux or other operating systems.The MMS server uploads the electrical data,alarm information to the MMS client using Report service,and the MMS client sends the control instructions to MMS server using Control service.In order to be compatible with the Modbus protocol used in the bottom layer,the Modbus and IEC 61850 protocol are required to be mapped to each other in MMS Server.Thirdly,the paper designs the Web monitoring system in detail,including its overall function architecture,software structure and MySQL database.Then,it presents the Struts 2,JDBC(Java Data Base Connectivity),Servlet,JSP(Java Server Pages)and other related Java Web technologies used by this system.After that,main management function in system are displayed and analyzed in this paper.The supervisor can check the real-time running data and the status of the microgrid through the real-time monitoring interface.The administrator can execute the control instructions through the real-time control interface according to the power generation plan to ensure the safety and stability of the microgrid.Finally,the paper introduces the microgrid hardware platform and server platform.And then MMS communication process and monitoring functions are tested and analyzed.Every function module of the system is running well,which can meet the design requirements.This paper has a reference value for the practical application of microgrid monitoring system.