直驱永磁风力发电系统按给定功率控制

Constant power control in direct drive permanent magnet wind power system

在分析风涡轮机组的功率转换特性的基础上,研究全风况下,分别利用全波整流+BOOST-CHOPPER电路和基于前馈解耦的PWM整流器,按给定功率控制直驱永磁风力发电系统(DDPGWPS)功率输出的电路。提出一种基于三环PI控制器的PWM整流控制电路,既控制永磁发电机的转速,又控制电磁力矩,从而实现对功率的稳健控制。进一步提出全风况下,基于实测风速、按给定功率控制DDPMWPS功率的组合控制策略。使用这种策略,设定给定功率等于预测的风功率平均值,当可利用的风功率大于给定功率时,DDPMWPS按给定功率控制输出,反之,则按最大风功率追踪的方法控制输出,从而能平滑由于风功率的随机性、间歇性而引起的DDPMWPS输出功率的波动,有利于大规模风力发电系统并网后的安全稳定运行及其他相关电力系统的操作。

Based on the analysis of the characteristics of power conversion of wind turbines, and under all wind conditions, the circuit with power output was studied according to a given power-controlled direct drive permanent magnet wind power system（DDPGWPS） respectively through a full-wave rectifier ＋ BOOST-CHOPPER and the PWM rectifier based on feed-forward decoupling. The PMW rectifies that control circuit based on three-loop PI controller is put forward, which both controls permanent magnet generator speed and its electromagnetic torque and finally realizes the stable control of the power. Furthermore, a control combination strategy was proposed for controlling the DDPMWPS power according to a given power and based on the measured wind speed under all wind condition. Through this strategy, the given power is set to be equal to the estimated wind power average, so when the available wind power is larger than the given power, the output power is the given power, on the contrary, the output power is set as the maximum. In this way, the fluctuations caused by the randomness and intermittency of wind power can be smoothed, which contributes to the secure and stable operations of the grid after grid connection of large-scale wind power generation system as well as to other power system operations.