A rotary valve-controlled pitch system is proposed to regulate the generator power and smooth power fluctuationsfor a wind turbine. Design details and dynamic modeling of this pitch system are presented and analyzed. ...A rotary valve-controlled pitch system is proposed to regulate the generator power and smooth power fluctuationsfor a wind turbine. Design details and dynamic modeling of this pitch system are presented and analyzed. A practical loadingcompensation approach is synthesized and involved in the pitch system to compensate for the external uncertain pitch loads. Theproposed pitch system and loading compensation approach have been experimentally evaluated in terms of generator powersmoothing and control accuracy. As demonstrated by the comparative experimental results, the proposed pitch system can beused to significantly smooth the generator power fluctuations and hence to improve the power quality as compared with a servovalve-controlled pitch system under the same operating conditions. The loading compensation approach can also be used to sig-nificantly attenuate the effects of external pitch loads and improve the robustness and reliability of the pitch system. The pro-posed pitch system features good control accuracy and cost-efficiency and hence is attractive for applications in modem large-scale wind turbines.展开更多
基金supported by the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(No.51221004)the National Natural Science Foundation of China(No.51275448)the Fundamental Research Funds for the Central Universities(No.2015QNA4005),China
文摘A rotary valve-controlled pitch system is proposed to regulate the generator power and smooth power fluctuationsfor a wind turbine. Design details and dynamic modeling of this pitch system are presented and analyzed. A practical loadingcompensation approach is synthesized and involved in the pitch system to compensate for the external uncertain pitch loads. Theproposed pitch system and loading compensation approach have been experimentally evaluated in terms of generator powersmoothing and control accuracy. As demonstrated by the comparative experimental results, the proposed pitch system can beused to significantly smooth the generator power fluctuations and hence to improve the power quality as compared with a servovalve-controlled pitch system under the same operating conditions. The loading compensation approach can also be used to sig-nificantly attenuate the effects of external pitch loads and improve the robustness and reliability of the pitch system. The pro-posed pitch system features good control accuracy and cost-efficiency and hence is attractive for applications in modem large-scale wind turbines.
文摘在半闭环控制的数控机床中,丝杠螺距误差是影响加工精度的一个重要因素,而利用激光干涉仪进行螺距误差补偿是解决这一问题的有效手段.文章介绍了雷尼绍激光干涉仪的工作原理及测试方法,采用XL-80型激光干涉仪对西门子数控机床进行等间距螺距误差测量和补偿,并对不同补偿数组输入前后的测试数据进行分析,结果表明,在螺距误差正确补偿后机床的定位精度从0.052 mm提高至0.012 mm,反向间隙值由0.023 mm降至0.005 mm.
