Research On Modeling And Control Strategy Of Hydraulic Turbine Speeding System

An accurate HTRS model is the basis for analyzing the trend of large-scale and complicated development of hydro-turbine units,which is of great significance to the stability control and research of power systems.With the continuous increase of the stand-alone capacity of a hydropower station,the huge inertia of the water flow,and the close electromagnetic coupling between the speed regulation system and the hydro-generator,these characteristics bring severe tests to the safe and stable operation of the power system,The control put forward new requirements and challenges.Based on the traditional hydraulic turbine modeling and analysis,this paper builds a more accurate and adaptable linear and non-linear model of the hydraulic turbine speed regulation system,identifies the parameters of the hydraulic turbine controller,and designs the control law.Based on the traditional PID control,a new control strategy is proposed.The main research results are as follows:(1)Linearization and non-linear comparison analysis of HTRS,which can reflect the changes of various parameters of the hydraulic turbine speed control system,hydro-generator system,excitation system,and output voltage during dynamic operation and fault transients.The nonlinear HTRS model and the linear model of the hydraulic turbine for simplified analysis on this basis further improve the accuracy of the model.The non-linear model focuses on the modeling and analysis of the hydro-generator part.At the same time,the power system operating conditions such as dynamic load changes,transient faults,and auto-reclosing are considered,which makes up for the shortcomings of the traditional hydro-turbine model which is too simplified and cannot be used for dynamic live simulation.(2)Through an in-depth analysis of the nonlinear dynamic characteristics of HTRS,and considering the control of HTRS on the turbine speed,torque,output voltage and current waveform when the turbine faces load fluctuations,a hybrid algorithm based on nested neural nets for fruit flies(BP-FOA)fractional PID(FOPID)control strategy.The fractional-order PID(FOPID)controller is a generalization of the traditional PID controller using the fractional-calculus method.The increase of its adjustable parameters provides greater flexibility for achieving the control objectives;compared with the traditional PID regulation rules There is a large difference,so the appropriate optimization algorithm is very importantfor the parameter adjustment of the FOPID controller,which proves that the BP-FOA algorithm controls the improvement of the speed and robustness of the FOPID controller.(3)The dual-objective control design of the FOPID controller is performed on a conventional hydraulic turbine regulating system based on the BP-FOA algorithm.The control parameters of the FOPID controller are selected as a dual-objective optimization problem,where the objective function is calculated by integrating the square error The integral of the time product squared error(ITSE).The effectiveness of the dual-target design is proved by comparing the current mainstream single-target control strategies with examples,and the superiority of the dual-target FOPID controller over the classic PID controller is verified.