永磁直驱风电系统网侧变流器控制策略研究

Research on Permanent Magnet Direct-drive Wind Power System Network Side Converter Control Strategy

介绍了永磁直驱风力发电系统网侧变流器的基本结构和工作原理。在建立了网侧变流器数学模型的基础上采用前馈解耦双闭环控制策略进行控制。实现了直流母线电压的稳定及有无功功率的解耦控制。针对传统PI控制器在跟踪和抗扰性能上无法同时达到最优的问题,提出一种基于二自由度PID控制的永磁直驱风力发电系统网侧变流器控制策略。并对二自由度PID控制器进行了化简得到一种简化的二自由度PID控制器。最后在Matlab/Simulink环境下对电网三相平衡状态、单相电压跌落状态及三相电压跌落状态的仿真实验验证了改进控制策略的有效性和正确性。

Firstly the basic structure and working principle of the network side converter in permanent magnet direct drive wind power system was introduced. Then based on the formulation of mathematical model of the grid-side converter, this paper studied the double-loop feedforward decoupling control strategy to realize the stability of the DC-Link and achieve the decoupling control of active power or reactive power. As for the problem of the traditional PI controller that cannot achieve optimal in tracking and disturbance resistance at the same time, a control strategy of the network side converter in permanent magnet direct drive wind power system is developed, which is based on the two degree of freedom PID control. And the two degree of freedom PID controller is simplified to get a simplified two degree of freedom PID controller. Finally, the effectiveness and the correctness of the improved control strategy was confirmed through simulation of grid three-phase balance state ,single phase voltage drop state and the three-phase voltage drop state by using Matlab/Simulink.