The Research On Advanced Control Of Medium Speed Coal Mill

As the modern technology growing into a deeper extent, the scope of the industrial producing became larger, and all of these had leaded to a problem of power. Especially for our China, after step into the new century, the industrial level of the country has meet with acceleration, and this means China becomes more relying on resources. The mineral power plant usually has larger capacity, and it is not limited by the seasons, the water-line, and the sunny time. Different with nuclear power-plants, there is no harmful radiation. The method of coal-burning is the main function in electric producing in China and many other countries.Coal is non-renewable energy resources, improve combustion efficiency and utilize coal resources on electric producing in an environmental friendly way is the mainstream ideology and researching emphases among the current world. The most usual way to solve energy problem nowadays is by using Superiority of Supercritical Units and Ultra-supercritical Units. Superiority of Supercritical and Ultra-supercritical Units has better quality on parameters of the main steam temperature and the main steam pressure, this means the steam of unit mass contains more energy, and has more power while working on the turbine. Generally the Superiority of Supercritical Units and Ultra-supercritical Units usually designed with larger capacity. To meet with the energy supply in mineral power plant, direct-fired system has been widely used. Compared with inter-bin coal pulverizing system, direct-fired system have less energy lose, and could follow the changing of peak load, it is more superiority.The medium speed coal mill discussed in this article is an very important auxiliary equipment in power plant. And it is the central part of direct-fired system. The particle size of coal powder and the safe production have initial effect on daily operation and the burning processes. The researching on medium speed coal mill should be all-around and hold a holistic attitude.The operation flowsheet and the characteristic of medium speed coal mill are discussed, and the paper also point out that the traditional PID controlling scheme cannot meet the ideal controlling quality, the schemes of the medium speed coal mill still need to be improve.The mechanism model and dynamic model of medium speed coal mill have been established after checking a large sum of literatures, and then bring up five schemes, Dynamic matrix controlling scheme; Fuzzy-PID parallel controlling scheme; Fuzzy-PID series-connected controlling scheme; Double fuzzy controller scheme. All of the five schemes traditional scheme have stimulate by using Matlab.The results indicate that each of the scheme have its own characteristics, The Dynamic matrix controlling scheme have the best quality, but it’s hard to tune the parameters; The series-connected controlling scheme take the second position on quality; The Double fuzzy controller scheme have large overshoot, the quality is the worst of the five schemes. The last not the least, all the parameters are well set, with the same disturbance, the controlling quality of five schemes brought up are better than traditional PID scheme.