| The monitoring and management of the electric power system have an important position in the petrochemical refining companies. According to requirement of a large petrochemical refining enterprise, this paper designed and developed a low-voltage power monitoring and electric energy management system integrated with the use of computer technology, instrumentation, communications networks, and other multi-disciplinary knowledge. This system is able to monitor the operating status of low-voltage power system, with functions of status display, fault alarm, historical record, and so on to ensure reliable operation of low-voltage electric power system. At the same time it can also collect electric energy consumption data of the whole factory, which is used for statistic and management in order to provide data support for assessment of enterprises’ electrical consuming and optimization of power supply. The system also has great significance on energy conserving and cost reducing.The main work includes the following aspects:1. According to the characteristics of the power supplying system of the petrochemical enterprise and actual needs of the system, we used four layers’ functional structure for the overall design, including the layer of data acquisition, the layer of data communications management, the layer of low-voltage power monitoring and the layer of electric energy management. In addition, we designed the function of every layer.2. Based on deployment of transformer substation, the paper designed the distributed architecture including the unit transformer substation, the area transformer substation and the total transformer substation, and selected the appropriate devices consisting data acquisition layer, and designed communicating networks based on Modbus and Profibus communicating protocols, constructed networked data communicate management layer and achieved the collection and forward of data which improved the reliability of data transmission and system’s efficiency.3. Using the ideas of combining centralization with distribution, we developed low-voltage power monitoring system based on the SPM configuration software, which are distributed in different level of the transforming substation, the higher transforming substations monitor the lower transforming substations. And established data channel in the configuration software in order to realize the acquisition of the whole factory’s power data.4. Designed the dual redundant of low-voltage electric power substation monitoring system which realized the low-voltage electric power monitoring system’s information synchronize of real-time data, historical data and alarms, and also ensured the reliability of the system operation.5. Based on B/S structure, we designed and developed the whole factory’s electric energy management system, and realized statistics of the power consumption and multi-level analysis of the whole electric power consumption using graphical man-machine interfaces, making power management transfer from extensive ways to fine ways, from distribution ways to systematic ways.6. Realized the data exchange between multiple systems. And designed and developed forwarding module of communicating management layer, which forward the state of low voltage power circuit to DCS system. When the total low-voltage power substation monitoring system visits the whole factory’s scheduling and integrated automation system, it can read and store the medium-voltage and high-voltage data. In the electric power management server we designed the database interface to transport the consumption data to the manufacturing execution system.This paper designed low-voltage electric power monitoring and the whole factory’s electric energy management system, and it operated successfully in petrochemical refining enterprises, which provides an effective protection for the reliable operation of low-voltage electric power monitoring and electric energy managing system of the whole factory. |
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