Research On The Application Of PLC In Hydro Power Plant Turbine Generator Local Control Unit Innovation

PLC(Programmable logic controller) is a kind of automatic control system which contains the technology of computer, automation and communication. It has the advantage of multiple function, high reliability, flexibility and simple program making. It has already been used in industry control field in domestic and aboard for years. Now, with the development of power system of our country, power plants are taking methods to raise their automation level to meet the requirements, the key point is to raise the level of CSCS(computer supervision and control system), and the main part of it relies on the function of LCU(local control unit).Firstly, this paper reviews the history and trend of CSCS and LCU(local control unit) for hydropower plant both at home and aboard. A new, PLC type LCU for the Second Channal Branch of GeZhouBa Hydropower Plant is developed according to the innovation inquirements of LCU.Then, according to related rules, hardware system design and software system design of the new LCU are described in detail. Hardware system design includes hardware type selection, hardware structure configuration and communication realization of LCU and other devices. Software system design includes hardware configuration, network configuration, data- base building, program making, and touch screen diagram making.After design, LCU is put into field tests and operation. The result of the tests and operation demonstrate that the application of PLC in Hydro Power Plant's LCU innovation is reasonable. The new LCU can meet the requirements of the innovation. The innovation has raised the automation level of the Hydropower Plant, and has contributed much to its high efficiency management.