基于双PWM变换器的永磁直驱风电系统协调控制

Coordination Control of Permanent Magnet Direct Driven Wind Turbine Based on Dual PWM Converter

由于双PWM变换器的永磁直驱风电系统在常规控制策略下,当风速变化时,存在直流侧电容电压波动较大、控制系统的响应速度较慢的现象,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作为前馈信号送到网侧变换器功率控制内环,对有功功率变化扰动直接调节,协调控制双PWM变换器两侧有功功率,实现瞬时有功功率平衡,有效抑制直流侧电压的波动,同时加快控制系统的响应速度。在此基础上,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。并通过对比仿真,验证了控制策略的正确性和有效性。

Considering the fact that in conventional control strategy, the DC side capacitor voltage of dual PWM converter-based direct-drive permanent-magnet wind power system has lager fluctuation and slower con- trol system response, a coordinated control strategy of active power feed-forward compensation was proposed, in which, having motor-side instantaneous active power sent to the grid-side converter power control loop as a feed-forward signal to regulate active power change disturbance directly and to control active power of dual PWM converter on both sides coordinately so that the instantaneous active power can be balanced and the DC bus voltage fluctuation can be inhibited effectively, as well as the control system response can be accelerated. On this basis, a compensation step added in the feed-forward control channel can further improve feed-forward control. Simulation and comparison results verify both correctness and effectiveness of this control strategy.