叶轮不平衡下的风力机自适应独立变桨控制策略

为减小风电机组叶轮不平衡引起的周期载荷,提出一种自适应独立变桨控制策略。首先,基于叶片旋转坐标系和轮毂静止坐标系之间的关系,揭示了机组在叶轮不平衡情况下的载荷特性及变化规律。其次,考虑不平衡周期载荷的频率随机组转速变化的特点,提出了一种谐振频率自适应于叶轮转速的比例—积分—谐振(PIR)独立变桨控制策略,并阐述了变桨控制器参数设计方法。最后,基于FAST-MATLAB/Simulink风电机组载荷及控制联合仿真平台,仿真比较了机组在叶轮平衡和不平衡两种状况下的载荷特性;并在IEC标准湍流风速下对所提自适应PIR独立变桨控制策略的载荷控制性能进行仿真,且将结果与传统比例—积分和比例—谐振独立变桨控制策略进行比较。结果表明,叶轮不平衡会导致风电机组产生频率变化的不平衡周期载荷,且相对传统控制策略所提自适应PIR独立变桨控制策略能够更有效地减小不平衡周期载荷。

An Adaptive Individual Pitch Control Strategy of Wind Turbines with Unbalanced Rotor

To mitigate cyclic loads in the wind turbine generator system (WTGS) caused by rotor unbalance, an adaptive individual pitch control (adaptive-IPC) strategy is proposed. Firstly, based on the relation of the rotational reference frame of blades and the fixed reference frame of hub, the loads characteristics are analyzed for a WTGS with unbalanced rotor. Then, considering that the frequency of the rotor unbalanced loads will vary with the speed of WTGS, a proportional-integral-resonant (PIR) based adaptive-IPC is presented in detail, with the resonant frequency of the R controller being adapted to the WTGS speed. And the pitch controller design method is also investigated. Finally, by using the FAST-MATLAB/Simulink based loads and control co-simulation system for WTGS, loads of a WTGS are simulated and compared in both balanced and unbalanced rotor condition. The load mitigation performance of the proposed adaptive-IPC is simulated with IEC turbulence wind speeds, and the results are compared with that of proportional-integral (PI) and proportional-resonant (PR) based traditional IPC strategies. Results show that the rotor unbalance will cause frequency-varying cyclic loads in the WTGS, and the proposed adaptive-IPC strategy is more effective than the two traditional IPC strategies. This work is supported by International Science & Technology Cooperation Program of China (No. 2013DFG61520), National Natural Science Foundation of China (No.51377184), Fundamental Research Funds for the Central Universities (No. CDJXS11151155) and Integration and Demonstration Program of Chongqing (No. CSTC2013JCSF70003).