Nonlinear Control Strategy For Hydraulic Turbine Generating Unit And Its Industrial Application Research

Hydraulic turbine regulating system is a complex nonlinear control system, which has non-minimum-phase characteristic and time varying parameters. Hydrodynamics and mechano-electric dynamics are all involved in such a nonlinear dynamic system. To satisfy the static and dynamic requirements, it is necessary to research the hydraulic turbine generating unit nonlinear control strategy with higher reliability and robustness. And the industrial application research of such a nonlinear control law also should be performed.These main contributions of this diesis are:1. Presented a method to change a non-affine nonlinear system to an affine nonlinear system, which approximately processes the original system on a specified operating point. Then, the relative approach of nonlinear control theory could be applied to design the nonlinear control law for the original system.2. Developed the mathematical model of hydraulic turbine regulating system with a Fransis turbine, single pressure water supply system and isolated operation condition. The hydraulic turbine generating unit nonlinear control strategy was designed based on disturbance-decoupling method of differential geometric nonlinear control theory. The hydraulic turbine generating unit nonlinear control strategy could adapt these dynamic hydraulic turbine transfer coefficients and attenuate the no-elastic water hammer effect in penstock. All these control variables are local measurements and are independent to electrical power supply system.3. An improved particle swarm optimization (PSO) algorithm was designed. And a weighted ITAE index of turbine speed error was taken as the fitness function of the improved PSO algorithm. The computer simulation results indicate that the application of the improved PSO algorithm for hydraulic turbine nonlinean control strategy parameters or PHD gains tuning is effective.4. These simulation models were developed in the MATLAB/Simulink-based software environment with S-function. These S-function based simulation models of hydraulic turbine transfer coefficients are all dynamic and time varying. Then, the dynamic and digital simulation model for the hydraulic turbine generating unit nonlinear control strategy was developed. The digital simulation results indicate that the hydraulic turbine generating unit nonlinear control strategy can improve the dynamic performance in hydraulic transients.5. The software of the hydraulic turbine generating unit nonlinear control strategy was developed. And then based on a 32-bit programmable computer controller (PCC), the digital controller with the hydrauli(?) turbine generating unit nonlinear control strategy was developed and connected to a 32-bit PCC-basec dynamic real-time simulator for hydraulic turbine regulating system. A closed-loop test was performed and the result also indicates that the hydraulic turbine generating unit nonlinear control strategy has a good performance for hydraulic turbine regulating system.