The Analysis Of Stability Of Waterpower-speed Control System Of Hydropower Station With Surge Tank Of Many Units Sharing In One Tailrace Tunnel

With the rapid development of hydropower projects,there are lots of power stations built or to be built with the properties of middle-head or low-head,high-discharge and long-conduit systems of hydropower station with surge tank of many units sharing in one tailrace tunnel such as sanbanxi, jinanqiao and guandi power station etc.When system suffers the action such as load fluctuation and head fluctuation,this arrangement has influence on the safety operation of system of water diversion and power generation.About the study of this kind of power station,the theory research can't come up with the application of project.Up to now, the system has been simply dealed with one conduit with one unit based on symmetrical conduits;same units and output; coherent governing.But in fact,most are not so.Based on the ripe theory of the hydraulic and governor system of one tunnel with one unit,a set of computation theory and method has been estabilished on the system of many units sharing in one tailrace tunnel by use of the equations of dynamics governor and increasing speed of units.The major contents are listed as follows:Chapter 1 Indicate the significance and objective of this paper, review the previous achievements of one conduit with one unit and then present the study purpose of this paper.Chapter 2:Set up a set of models about small transient condition including rigid model including stability and regulation quality and stretch model including pane figure of regulation quality applying to the system of hydropower station with surge tank of many units sharing in one tailrace tunnel.Chapter 3:Present the theory of the analysis of stability and computation on regulation process to the system of hydropower station with surge tank of many units sharing in one tailrace tunnel.Chapter 4:Based on the previous fruits of this thesis,through a practical example, demonstrate the influnce of different factors such as unsymmetrical conduits; different units;comparing rigid model with stretch model on the quality of regulation;no-load fluctuation and different output.Chapter 5:Based on the previous fruits of this thesis,utilize the rigid model,by introducing the factors such as governor,penstock and turbine characteristics,the feedback of water level and the length of tailrace tunnel,the location of bifurcated pipe.And then,through a practical example, give the discussions on the problems such as the influences on steady cross-section area of surge-tank.Chapter 6:Summarize the whole paper, and present the future research directions and emphasis.