Research And Application On The General PLC Control Platform In Three Gorges Left Bank Hydropower

As a set of flood control, shipping and power generation and other multi-target integrated development of conservancy projects, the fourteen power station group have been installed the left bank of Three Gorges Project. In order to better meet the operational units, it needs integrating the PLC control system of the left bank of the Three Gorges Power Station involving all systems. Its purpose is to make the PLC system to better communication and work together. In this paper, the PLC common control platform for the Three Gorges Left Bank Power Station is proposed. The purpose of the paper is aimed to develop the universal platform and provide the necessary technical design of the future research.The left bank of the Three Gorges Power Station is consisted of the different control system, including a variety of PLC systems, which have the strong interaction between the different PLC and other system. And due to the different control systems manufacturer of the PLC which have their own private communication network means, so various models are not compatible with no clear consistent standard; meantime, the types variety of programming components and the different incompatible of programming languages will result a different communication difficulties between the PLC. It is not conducive to the comprehensive control of power plants. With the Three Gorges generating units are gradually making the normal operation of the stage, this issue will become increasingly acute.In light of this issue, the design of the PLC common graphical control platform is researched in this paper. The design idea of object-oriented programming is used in the platform and with graphic style to achieve the same programming and debugging. It can not only replace the large number of PLC programming software debugging, but also to achieve control of the network between the different models PLC networking and communications. The platform is based on the popular soft PLC of the contemporary international. It uses Delphi as a development tool to develop the platform application. The platform of the PLC in accordance with the mainstream protocol, a star of the network structure and the serial communication technology, the PLC will automatically identify the type and format of instruction, and implement various exchanges between the PLC systems. Through the General PLC control platform for testing by test simulator, it meets the real-time, accuracy, reliability and operational requirements of cross-platform and has a friendly man-machine interface, so it can satisfy PLC control system requirements various networking collaboration control of the practical requirements in the left bank of the Three Gorges Power Station. The platform has been the competitive products above the PLC. It promotes the unit operation stability of the Three Gorges Power Station and reduces the operating costs significantly. So the economic and social benefits of the Utility run have been markedly improved.