The Research And Design Of Power Monitor System Based On IEC61850in Zhuhai LNG Stations

With the development of science and technology as well as the continuousimprovement of productivity, the proportion of the electric power costs and the operatingcosts which are associated with electric power has increased significantly. An impeccableelectric power monitoring system can be fully used to supervise the power quality, improvethe efficiency, reduce the loss and the operating costs. The topic is originated from theproject LNG (Liquefied Natural Gas, Liquefied Natural Gas). To insure the normaloperation of the tank equipments, there should be a set of intelligent power monitoringsystem which is simple, safe, reliable and high instantaneity to guarantee the continuity ofelectric power supply.First, combining the actual requirement of Zhuhai LNG project, this paper analyzes thenetwork topology structure of the electric power monitoring and control system of theZhuhai LNG pot area，introduces the general requirements of the monitoring system design,configuration and performance. The substation layer of the electric power monitoring andcontrol system uses the monitoring software and remote communication device based onIEC61850standard, while the substation layer network applies the dual redundant networkwith the real-time and high reliability features, the spacer layer devices use the digitalprotection and control equipment based on IEC61850standard and the electric parametermeasuring instrument based on Modbus, etc.Secondly, the paper introduces the IEC61850standard, illustrates the principle andprocess of modeling as well as the configuration language, mainly using in the incomingline near the LNG tank measurement and control protection device’s model as example witha detailed discussion of the whole process of modeling and SCL file description of theserver, logical devices, logical node, data objects, data attribute and data sets, etc.Again, this paper explains the MMS communication between the substation layer andthe spacer layer of the monitoring system, with the introduction of the abstractcommunication service interface, specific communication service mapping, MMScommunication mode and communication protocol stack. Then introduces the specificconfiguration of MMS communication combined with the application of the actual project,and uses the MMS-Ethereal caught tools to analysis the MMS communication equipmentinitialization message, MMS report and MMS message control message, ensures thedetection research on the monitoring and control system for normal communication. Finally, this paper studies the implementation of the monitoring system based onPowerLogic SCADA software, introduces the realization of various function such as thetrend of monitoring data acquisition interface, graphic display, alarm and record, reportforms, circuit breaker switch control, switching in both English and Chinese,etc. This paperdiscusses the different voltage grade of sub module and the corresponding data, and thefunction and composition of database, analyses the reliability and security of the monitoringsystem, verifies the feasibility of the system design and stability.The first and second phase of Zhuhai project LNG had successfully put into operationin September of this year. The local electric power monitoring and control system has stableoperation, nice security, high stability, powerfull expanding, which satisfy the requirementsof Zhuhai LNG tank field electric power monitoring and control system. Moreover, thespace has reserved for expansion of the third phase.