依据对风力机变速恒频变桨距控制原理,提出了电机电磁阻转矩调节和分段PID权系数分配的控制算法分别实现变速恒频和独立变桨距控制,同时由于风力机系统的大惯性、迟滞,采用了变桨距与变速恒频两算法切换过程以预测功率为界的综合控制算法代替了传统控制中以额定功率为界以减小输出功率的波动。将控制算法应用到自行搭建的半物理仿真试验台上进行试验分析,在风速高于额定值时,独立变桨距控制不仅稳定了发电机输出功率,而且与统一控制相比大大减小了桨叶拍打振动;当风速在额定值左右变化时,运用综合控制算法比传统控制大大稳定了发电机输出功率。
The variable-speed constant-frequency pitch-controlled law was obtained by analysis of wind turbine aerodynamics. The electromagnetic damping torque regulation of brushless doubly generator was used for variable - speed constant - frequency control and the piecewise PID with weight number algorithm was applied for individual pitch control. Because of large inertia and hysteresis of wind turbine, pitch control and variable-speed constant-frequency control were switched at predictive power instead of rated power to decease output power fluctuation. All these control strategies were used in the semi-physical simulation test-bed. Test result shows that when the wind speed is up the rated one, the blade flapwise is greatly deceased and the output power is kept around the rated. When the wind speed is varied around the rated one, the output power fluctuation is reduced.