Research On Control Strategy Of Brushless Doubly Fed Generator Based On Improved Particle Swarm Optimization

The brushless doubly fed machine not only has inverter capacity is small, independent control of active power and reactive power, and can be run in a different way, is more suitable for the generator used in variable speed constant frequency and constant voltage power generation system. But no brush motor applications in independent power system usually vulnerable to external disturbance and failure problems, so how to make power system under external disturbances can stable operation is an important goal of this paper.First, according to the basic structure and the working principle of the brushless doubly fed motor and based on brushless doubly fed motor current research, the mathematical model of the brushless doubly fed generator under abc three-phase stationary coordinate is established, then do the coordinate transformation and deduce the motor mathematical model under rotor speed dqO and the dual synchronous coordinate system. According to the mathematical model of the rotor speed coordinate, under the environment of MATLAB /Simulink, the simulation model and open loop control module of brushless doubly fed induction generator is established,a simulation analysis was carried out to verify the correctness of brushless doubly fed induction motor simulation model.Secondly, according to the brushless doubly fed generator mathematical model in the double speed coordinate system, the power winding flux is oriented to the d axis of the synchronous coordinate and the vector decoupling control scheme is designed, which achieves an decomposition of control winding current component, the torque component and the excitation component, to control the torque and flux. Based on the original motor simulation model, build a simulation model of the vector decoupling control of Brushless Doubly Fed Generator, and do the simulation analysis respectively under three different conditions, that is in sudden load, anticlimax load and speed mutation, to verify the vector decoupling control system's advantages with respect to the open loop system performance,and also comes to the conclusion that in the vector decoupling control system, the traditional PID has defects.Finally, in order to further optimize the brushless doubly fed induction motor vector decoupling control system, improve the performance of brushless doubly fed independent generator system and ensure the stable operation under different conditions, an improved particle swarm optimization algorithm is used to of optimize brushless motor control system PID parameters. the traditional particle swarm optimization (PSO) algorithm has the problem of premature convergence and low precision, analysis the inertia weight and learning factor of the particle swarm algorithm, an improved particle swarm optimization algorithm is used to optimize the brushless motor control system PID parameters, using adaptive method to adjust the inertia weight and using variation method to adjust the learning factor.By MATLAB/Simulink, simulate and analysis the different conditions of the brushless doubly fed generator system. The improved particle swarm optimization algorithm is applied to the design of PID controller. Simulate and compare the power system before the optimization with optimized system, the brushless doubly fed stand-alone power system with the improved particle swarm optimization algorithm has stronger robustness and system performance is improved.