风电变桨电机参数对控制系统影响分析及改进辨识方法

Influence of parameters on control system and improved identification method of pitch motor in wind turbine generator system

针对风电机组变桨电机参数变化和负载不确定等带来变桨控制系统鲁棒性差的问题,分析变桨电机参数对控制系统的影响并提出参数辨识改进方法。首先,基于变桨电机控制系统中的复合磁链估算模型,针对不同参数的变化对磁链估算影响不同的问题,利用频率响应函数法(FRF)进行定量分析,获取影响较大的参数。其次,基于模型参考自适应辨识方法(MRAS),将辨识初始值作为补偿项,以克服电机转速和负载转矩变化对辨识结果的影响,建立转子时间常数Tr的在线辨识改进模型,提出考虑参数辨识的风电机组变桨控制策略。最后,对风电机组变桨电机及其控制系统进行动态仿真和样机实验。结果表明,Tr对变桨电机控制系统的影响较为明显,考虑在线辨识后的改进模型及控制策略具有更好的鲁棒性。

Uncertainties of parameters and load in pitch motor may lead to low robustness of pitch control system.Therefore,influence of motor parameters on control system was analyzed and an improved parameter identification method was presented.Firstly,based on the complex flux estimator in pitch control system,impact of motor parameters on the flux estimator were analyzed using frequency response functions(FRF),which could derive the key parameter.Secondly,based on the model reference adaptive system(MRAS),the initial value of identification was regarded as the compensation term to weaken the effect of variable motor speeds and load torques on identification result,then the improved online identification of the rotor time constant Tr and pitch control strategy considering parameter identification in wind turbine system were presented.Finally,simulation and prototype test of pitch motor control system were carried out.The result validates that Tr has a prominent impact on the pitch control system,and the improved identification model and control strategy considering online identification would be more robust.