永磁直驱风电系统双PWM变换器前馈补偿控制

Feed forward compensation control of dual PWM converter for permanent magnet direct driven wind turbine

永磁直驱风电系统双PWM变换器在常规控制策略下当风速变化时,直流母线电压波动幅度较大、控制系统的响应速度较慢,这将不利于系统的安全、稳定运行。为此,根据瞬时有功功率平衡关系,提出有功功率前馈补偿协调控制策略。将发电机侧瞬时有功功率直接前馈于网侧双闭环瞬时有功功率内环给定,避开了电压控制外环对功率的间接调节,加快了控制系统的响应速度,协调两侧变换器瞬时有功功率及时平衡,有效抑制了直流母线电压的波动。为加强前馈控制对扰动的抵消作用,在前馈控制通道中加入补偿环节,进一步提高前馈控制效果。对比仿真结果验证了控制策略的正确性和有效性。

As for dual PWM inverters in direct-drive permanent-magnet wind power system under the normal control, when the wind speed changes, the DC bus voltage fluctuates greatly and the control system responds slowly, which is unfavourable to system safe and stable operation. Therefore, according to the instantaneous active power balance relationship, this paper puts forward the control strategy of coordination power feed forward compensation. It makes the generator side of instantaneous active power be a feed forward in the grid side converter of double loop instantaneous active power ring given, avoids the voltage control loop indirect regulation of power, accelerates the respond speed of control system. Moreover, it achieves the coordination of the DC bus side instantaneous active power timely ba｜ance, effectively restrains the DC bus voltage fluctuation. In order to strengthen the feed forward control to offset the disturbance, it is necessary to join the compensation in the feed forward control channel, to further improve the feed forward control effect. The comparison of simulation verifies the correctness and effectiveness of the control strategy.