| As the computer monitoring system come into increasing use in hydropower stations, it proposes new requirements of the monitoring and management of the gate automation. and implementation of intelligentized monitor and control of sluice gates is imperative.The design and research of Station gate monitoring system ,not only can make the water gates control flexibility and fast, but also can enhance the reliability and safety of hydropower operation, and present Theoretical basis and technological means to improve the automation level of hydropower station and achieve the operation mode in which less people workAccording to the current requirements of the gate control system in small and medium hydropower stations, the thesis has proposed hierarchical and distributed gate control. The control system is composed of two layers, the management of monitoring center and LCU (local control unit). PC-level monitoring center communicated with the LCU via Industrial Ethernet. Similarly, field testing equipment (water level sensors, gate opening device) pass the collected data through the field bus to the PLC, PLC deals with these data and transmits to the host computer via Ethernet, then the PC displays the operating conditions of gate with vivid visual figures, graphics, text, tables and other forms display the operating conditions of the gate in time. At the same time, the operators sent the command of operation gate through the interactive interface, in terms of the given permission, the LCU receives commands and performs the appropriate action.As the core of sluice control system of hydropower station, PLC has significant advantages. PLC is the computer designed for industrial control, and optical isolation devices are used in input/output (I/O) interface circuit to achieve electrical isolation between the PLC's internal circuit and the external circuit of industrial local devices, which improve the anti-jamming capability of the system. It has a wealth of input/output interface modules, and it can be directly connected with the local devices without setting the A/D or D/A conversion device compared with the MCU or industrial computer, and it has the advantages that simple structure, install and use easily. Additional, it also has merits such as powerful, small, cheap and cost-effective. Thus, PLC has been popularized in control system of hydropower station.The Hierarchical distributed control system rules for centralized operation, decentralized control, comprehensive management and divide and autonomy design, therefore, the gate control system has integrated management capability and operational reliability. In addition, the host monitor (PC) in monitoring center and controller (PLC) in local control unit have adopted Dual redundant hot standby mode. Two host monitors or master controllers can work simultaneity as well as one is a host, the other as a backup machine. When the host fails, the spare can replace it automatically and complete the monitoring and control tasks, so that it further improves the reliability of the monitoring system.In this paper, the design and methods of implementation of gate control system for small and medium hydropower stations(water diversion hydropower station) were studied. It also designed software and hardware of local control unit and workstation, including the selection and design of software and hardware of sensors and controllers used in local control system and monitoring center, communication between them, etc. Eventually, the paper gives a complete design and methods of implementation of controlling and monitoring system. What's more, fuzzy control method was applied to the water level control system of sluice, and water level fuzzy controller was designed. Using PLC fuzzy control not only improve the automation level of the system, but also improve the intelligence of the control system.Finally, in order to ensure the accuracy and stability of the control systems, this paper elaborates a series of anti-jamming measures of monitoring system. |
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