| The governing system of tubular turbine unit is a closed-loop control system with the governor of tubular turbine unit as the controller and the water turbine generator unit and diversion system as the controlled object.The basic task of the governing system of tubular turbine unit is to continuously regulate the active power of the turbine generator unit according to the change of load and maintain the speed(frequency)of the unit within the specified range.The performance of the regulation system of hydro generator units has a significant impact on the safe and reliable operation of power station units.The characteristic parameters of the controlled object of the governing system of the tubular turbine unit are related to the operating conditions and loads of the unit itself.Therefore,in order to obtain good system dynamic quality,the control parameters of the governor of the tubular turbine unit at different operating points should also be different,otherwise,the dynamic characteristics of the governing system of the tubular turbine unit will inevitably deteriorate,or even lose stability.At present,although the manufacturers have given the adjustable range of PID control parameters of the governor,most manufacturers have given a group of PID parameters.The selection of this group of control parameters requires a large number of tests.However,in view of the requirements of the power station for safety,reliability and economy,it is unrealistic to carry out long-time,multi operating point and large-scale tests on the actual hydraulic turbine generator unit.In order to solve these problems,based on the comprehensive characteristic curve and runaway characteristic curve of the turbine model of the tubular unit,and supplemented by the corresponding operating parameters,such as the operating relationship between the opening and output of the unit under a specific head,the load rejection process curve of the unit,etc.,the artificial neural network is used to simulate the flow characteristics and torque characteristics of the turbine,and the simplified characteristic line method with variable sampling frequency is used to simulate the water diversion system,The nonlinear modeling of the governing object of the turbine governing system of tubular units is established.For the existing two main control modes of the power plant,namely,speed control mode and opening control mode.Study the dynamic quality of the regulation system under two control modes,including:simulation study of the dynamic quality of the regulation system under the original governor parameters and rated head,and simulation study of the dynamic quality of the regulation system under the original governor parameters within all possible head ranges.The biogeographic algorithm is used to find out a set of optimal parameters,and the corresponding dynamic process simulation is given.A real-time closed-loop system is formed by connecting the real governor with the real-time simulation system of the nonlinear model of the operating unit,and various closed-loop dynamic characteristic tests are carried out on it.Thus,the dynamic quality evaluation of the existing regulation and control parameters of the power plant regulation system in all working conditions is given,and the optimal control parameters of the governor are obtained in all possible working ranges of water heads. |
