直驱永磁风力发电机无位置传感器直接转矩控制的研究

发布时间：2018-04-01 14:28

本文选题：直驱风力发电　切入点：直接转矩控制　出处：《福州大学》2014年硕士论文

【摘要】：风能作为世界上发展最快的新能源,得到全世界广泛的关注。直驱永磁风力发电相较双馈风力发电具有转换效率高、并网功率控制灵活等特点,成为风力发电技术重要的研究方向。直接转矩控制(DTC)是一种先进的交流电机控制策略,它具有转矩响应快,控制结构简单等优点。将直接转矩控制方法用于直驱风力发电系统中,具有重要实际意义。但传统直接转矩控制具有磁链、转矩脉动大等问题。永磁同步电机转子位置信息常依靠传感器获得。传感器的安装使得系统安装成本增加,维修困难,且易受环境因素的影响。因此,无位置传感器控制技术正成为直驱风力发电系统研究的热点。本文首先介绍了永磁同步发电机的数学模型,同时分析了风力机模型及运行特性。根据理论分析搭建直驱风力发电模型,并把直接转矩控制作为控制策略,在Matlab/Simulink中进行仿真,仿真结果表明搭建的直驱永磁风力发电直接转矩控制系统性能良好,为进一步实验搭好基础。其次分析了直接转矩控制中传统的电压积分型磁链观测器,分析几种常用的改进法的性能,并提出一种新的电流型观测器。该方法避免了电压积分法中直流偏移和初始值带来的弊病,也解决了电流型观测器在实际应用时电感测量不准确引起的系统问题。仿真结果表明该方法具有可行性和有效性。第三,在分析永磁同步电机数学模型的基础上,根据功角与转子位置的关系,推导了基于定子磁链的永磁同步电机转子位置检测方法。该方法可用于转子位置的实时检测。第四,采用模糊直接转矩控制的方法取代传统直接转矩控制。将模糊控制理论引入直接转矩控制中,根据区分磁链和转矩的偏差而做出适当的决策,因此优化开关状态的选择。仿真结果表明该方法对转矩和磁链的脉动有明显的抑制效果,大大改善了直接转换控制的性能。最后在理论和仿真的基础上,本文以TMS320F2812为控制芯片,搭建控制电路。设计了电压和电流检测电路,PWM驱动及保护电路。在硬件电路的基础上,编写C语言程序,并进行进一步的调试。在1Kw的永磁同步电机对拖实验平台进行实验,完成主电路、控制电路和相关电路的搭建。实验结果表明,本文提出的无位置传感器技术能进行准确的位置检测,精度高,动态性能较好,可考虑作为实际生产应用。
[Abstract]:Wind energy, as the fastest growing new energy in the world, has received wide attention all over the world.Compared with doubly-fed wind power generation, direct-drive permanent magnet wind power generation has the characteristics of high conversion efficiency and flexible power control, which has become an important research direction of wind power generation technology.Direct torque Control (DTC) is an advanced AC motor control strategy, which has the advantages of fast torque response and simple control structure.It is of great practical significance to apply direct torque control method to direct drive wind power generation system.But traditional direct torque control has many problems, such as flux chain and torque ripple.The rotor position information of permanent magnet synchronous motor (PMSM) is usually obtained by sensor.The installation of sensors increases the installation cost, makes maintenance difficult, and is easily affected by environmental factors.Therefore, sensorless control technology is becoming a hot spot in the research of direct drive wind power generation system.In this paper, the mathematical model of permanent magnet synchronous generator (PMSG) is introduced, and the wind turbine model and its operation characteristics are analyzed.According to the theoretical analysis, the direct torque control (DTC) is used as the control strategy, and the simulation results in Matlab/Simulink show that the DTC system is of good performance.To lay a good foundation for further experiments.Secondly, the traditional voltage integral flux observer in direct torque control (DTC) is analyzed, and the performance of several commonly used improved methods is analyzed, and a new current-mode observer is proposed.This method avoids the disadvantages of DC offset and initial value in voltage integration method and solves the system problem caused by inaccurate measurement of inductance in practical application of current-mode observer.Simulation results show that the method is feasible and effective.Thirdly, on the basis of analyzing the mathematical model of PMSM and according to the relationship between power angle and rotor position, the rotor position detection method of PMSM based on stator flux linkage is deduced.This method can be used to detect rotor position in real time.Fourthly, fuzzy direct torque control is used to replace the traditional direct torque control.The fuzzy control theory is introduced into the direct torque control and the appropriate decision is made according to the deviation between the flux chain and the torque, so the switching state is optimized.The simulation results show that this method can restrain torque and flux ripple obviously and improve the performance of direct conversion control greatly.Finally, on the basis of theory and simulation, this paper uses TMS320F2812 as the control chip to build the control circuit.A PWM drive and protection circuit is designed for voltage and current detection circuits.On the basis of hardware circuit, C language program is written, and further debugging is carried out.The main circuit, control circuit and related circuit are built in 1Kw permanent magnet synchronous motor (PMSM) test platform.The experimental results show that the position sensorless technique proposed in this paper can be used for accurate position detection with high accuracy and good dynamic performance. It can be considered as a practical application.
【学位授予单位】：福州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM315

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