Study On Automatic Generation Control Of Middle And Small Scale Hydropower Plant

With the fast development of national economy, the requirement to electricity quality and power system's automation level is continually improving. Now, automatic generation control (AGC) has been one of the most important automatic level criterions of power system. Hydropower plant is the most important executer of AGC system, for it is easy to adapt its output of active power. The application of hydropower plant's AGC is the key to power system's AGC. However, middle-and-small-scale hydropower plant's automation level is urgent to be improved. In order to achieve the goal that all of middle-and-small-scale hydropower plants will realize non-attended before year 2010, study on middle-and-small-scale hydropower plant's AGC technique and its application is becoming more and more significant.The main contents and achievements of this dissertation as follows:Firstly, based on the analysis of present AGC technique, this dissertation brings forward a middle-and-small-scale hydropower plant AGC scheme according to actual situation. The scheme specifies AGC functions and introduces AGC program structure, which could satisfy most middle-and-small-scale hydropower plants' requirements.Turbine is a nonlinear and non-minimum phase system, it is hard to model accurately. This dissertation points out the defects of the widely used simple linear model, improves the present model. This dissertation introduces the modeling method of each parts of hydro generator set regulator system in detail, establishes single and multi hydro generator set model of active power closed loop control system. Through the simulation, the model's validity is proved.The water level of reservoir needs to be controlled at setting height for the needs of shipping and preventing flood. Generating according to constant water head could improve the hydropower plant's economy benefit. This dissertation presents one kind of generating control arithmetic according to constant water head, which is adapted for middle-and-small-scale hydropower plant. Then, this dissertation establishes the constant water head control model. Through the simulation, the model's validity and feasibility is proved.