【作者】 刘姣；

【导师】 年珩；

【作者基本信息】 浙江大学 ， 电机与电器， 2011， 硕士

【摘要】 随着能源危机和环境危机的日益严重,以风电为主的新能源已成为现代社会发展的需求。目前,永磁直驱风力发电系统受到的关注度越来越高,与双馈风力发电系统相比,它具有系统结构简单、效率高、可靠性和维护性好等优点。风电用永磁同步发电机为多极低速发电机,其高性能控制需要精确的转子位置和转速信号去实现磁场定向。在传统运动控制系统中,通常采用光电编码器或旋转变压器来检测转子的位置和转速。然而,这些机械式的传感器增加了系统的成本,并且降低了系统的可靠性。因此,本文对变速恒频(VSCF)永磁直驱风力发电机(PMSG)无位置/速度传感器控制以及电机参数辨识算法的基础理论及控制策略进行了从理论到仿真,从仿真到实验的全方位深入研究。本文首先研究了永磁同步发电机无传感器控制时两相旋转坐标系下的定子电压方程,建立了转子位置误差估算的数学模型。随后,介绍了锁相环的结构和工作原理,并设计了锁相环控制器用以估算PMSG转速和转子位置。最后,先后通过仿真、实验对锁相环控制器估算和实际电机转子位置和转速进行对比,仿真和实验结果证明了所做理论研究与分析的正确性和有效性。由于转子位置误差的估算需要电机参数,而电机参数会随着电机运行条件变化而变化,因此,为保证锁相环控制器的精度,本文对电机参数的在线辨识进行了深入的研究。本文首先介绍了递归最小二乘法(RLS)的原理,并研究了建立在RLS算法上的电机参数辨识模型,通过实验结果证明了RLS算法的有效性。最后本文通过对一台3.8kW样机系统的设计与研制,进一步验证了辨识得到的电机参数应用于转子位置误差估算模型后,锁相环控制器性能确有改善。更多还原

【Abstract】 With the growing of the environmental problem, the wind power generation is considered to be the most useful and effective energy. At present, permanent magnet synchronous generator(PMSG) has obtained more application in the variable speed constant frequency(VSCF) wind power generation system, which has advantages of simpler structure, higher generation efficiency and more reliable operation performance, compared with the doubly-fed induction generator(DFIG). Generally, to implement the maximum power point tracking(MPPT) control and keep stable generation performance, it is necessary to detect rotor position and speed to apply vector control for PMSG. However, additional mechanical position sensor not only increases the cost and complexity of the system, but also impairs the reliability. Therefore, it is important to investigate the sensorless control strategy of VSCF performance of PMSG with the consideration of the influence on the PMSG control due to the generator parameter variation.Firstly, the stator voltage model of PMSG in the estimated synchronous reference has been proposed. Then, the mathematical model of rotor position error estimation has been deduced. Secondly, the theory of phase-locked loop(PLL) has been introduced and the PLL controller has been designed to estimate the rotor position and rotor speed. Simulation result and experiment result both show that the PLL controller can obtain good performance.The sensorless operation performance may be deteriorated while PMSG parameters used to the position detecting model vary with operation conditions. Therefore, it is necessary to consider the on-line parameter identification of PMSG to improve the accuracy of the estimated rotor speed and position. The theory of recursive least-squares(RLS) method has been introduced at first. And then, the mathematical model of parameter identification based on RLS has been proposed. At last, experiment result demonstrates that RLS can be utilized in parameter identification.In the end of the thesis, the design and development of a 3.8kW rated hardware system have been proposed. And the experimental results will show that the estimated PMSG parameter can improve the performance of PLL controller.更多还原