基于干扰观测器的直驱永磁同步风电系统输出功率控制研究

摘要

This paper studies the variable pitch angle control of the direct drive permanent magnet synchronous wind power system with the wind speed above its rated value.Firstly,the nonlinear mathematical model of permanent magnet synchronous wind power system is established,and the linear wind power system state space model is obtained through expanding the nonlinear model at its best operating point.The pitch angle controller based on the sliding mode control (SMC) algorithm is designed to smooth the output power of wind power system according to the state space model.In order to reduce the inaccurate control of the sliding mode control that designed based on the system's inaccurate boundary,the disturbance observer is designed to estimate the system uncertain value of the system.Furthermore,the estimated value of the disturbance is used to design the pitch angle controller with sliding mode algorithm,which improves the accuracy of the controller and ensures that the output power of wind power system is more stable when the wind speed is higher than rated value.Finally,the simulation model of the whole wind power system is built based on the Matlab/Simulink platform,and the simulate results indicate the proposed pitch angle controller with sliding mode algorithm based on the disturbance observer can better smooth the output power of wind power system with different higher wind soeeds.%研究高于额定风速的直驱式永磁同步风电系统变桨距控制.首先建立直驱式永磁同步风电系统的非线性数学模型,然后在最佳运行点处展开得到线性化风电系统状态空间模型,根据该模型设计基于滑模控制算法的桨距角控制器来平滑风电系统的输出功率.为了减小利用系统不确定项的界设计滑模控制器存在控制的不精确,考虑设计干扰观测器试估计系统不确定项的值,并将干扰估计值应用到滑模桨距角控制器的设计中,提高了控制器的精度并且保证高于额定风速阶段风电系统的输出功率更加平稳.最后,基于Matlab/Simulink平台搭建了风电系统的整体仿真模型,仿真结果表明所设计的基于干扰观测器的滑模桨距角控制器可在不同类型高风速输入扰动下,更好地平滑风电系统的输出功率.