无刷电励磁同步电机励磁控制系统研究

发布时间：2018-03-25 11:18

本文选题：无刷励磁　切入点：PID控制　出处：《沈阳工业大学》2015年硕士论文

【摘要】：无刷电励磁同步电机是近年来提出的一种新型电机，该电机除具有常规电励磁同步电机转速恒定、功率因数可调及效率高等优点外，还具有无电刷滑环结构、维护成本低、可靠性高等特点，特别适用于易燃易爆及风力发电等应用领域。这种电机定子上有两套极数不同的绕组，一套为2p极三相电枢绕组，直接与电网相连接；另一套为2q极直流励磁绕组，为电机提供励磁电流，转子为磁障笼型混合式转子。由于这种电机的发展较晚，目前还没有与之相适应的励磁控制系统能够配合这种电机运行，，为了使无刷电励磁同步电机能够发挥出最佳性能，本文设计并研制了一套无刷电励磁同步电机励磁控制系统。首先，本文研究了无刷电励磁同步电机的工作机理，对该电机特殊的定转子结构和工作方式进行了具体的介绍，并与传统的旋转整流器式无刷电励磁同步电机进行了对比分析，明确了研究的目的和意义。其次，本文使用有限元仿真分析软件Ansoft Maxwell建立了无刷电励磁同步电机的有限元分析模型，利用多领域仿真分析软件Simplorer建立了控制系统仿真模型，并将有限元模型导入到Simplorer中进行联合仿真。使用场路结合的方法对变负载恒定发电机端电压等工作状态进行了仿真分析，针对仿真中发现的问题，本文对励磁控制系统的电路结构进行了优化设计，改善了控制器的性能。再次，本文针对无刷电励磁同步电机对于励磁控制系统的需求，提出了针对不同工况的励磁电流控制策略。在电动机工况中，励磁控制系统根据电机转速自动判断何时对电机进行牵入同步，通过调节励磁电流来调整电动机功率因数。在发电机双闭环应用工况中，励磁控制系统使用双闭环控制算法使发电机发出的端电压保持在给定的数值附近，当发电机负载发生突变时，励磁控制系统迅速调整励磁电流的大小以应对这种变化，最大限度的保证发电机输出电压的稳定。最后，本文设计并研制了一台无刷电励磁同步电机励磁控制系统，包括励磁控制器的硬件结构设计和控制核心的软件编写。励磁控制系统利用微控制器的硬件PWM信号和离散式数字PI算法以闭环控制的方法对无刷电励磁同步电机的励磁电流进行了精确的控制，对本文所提出的励磁控制策略的有效性进行了验证。
[Abstract]:Brushless excitation synchronous motor is a new type of motor proposed in recent years. In addition to the advantages of constant speed, adjustable power factor and high efficiency of conventional electric excitation synchronous motor, it also has brushless sliding ring structure and low maintenance cost. Because of its high reliability, it is especially suitable for applications such as flammable and explosive power generation and wind power generation. There are two sets of winding with different poles on the stator of this kind of motor, one is 2p pole three-phase armature winding, which is directly connected to the power grid; The other is the 2Q DC excitation winding, which provides the excitation current for the motor, and the rotor is the magnetic barrier cage type hybrid rotor. Due to the late development of this kind of motor, there is no excitation control system that can cooperate with the motor at present. In order to give full play to the best performance of brushless excitation synchronous motor, an excitation control system for brushless excitation synchronous motor is designed and developed in this paper. Firstly, this paper studies the working mechanism of brushless excitation synchronous motor, and introduces the special structure and working mode of the motor. And compared with the traditional rotary rectifier brushless excitation synchronous motor, the purpose and significance of the research are clarified. Secondly, the finite element analysis model of brushless excitation synchronous motor is established by using the finite element simulation analysis software Ansoft Maxwell, and the control system simulation model is established by using the multi-domain simulation analysis software Simplorer. The finite element model is introduced into Simplorer for joint simulation. The working state of variable load constant generator terminal voltage is simulated and analyzed by the method of field circuit combination. The problems found in the simulation are pointed out. In this paper, the circuit structure of excitation control system is optimized and the performance of controller is improved. Thirdly, according to the demand of brushless excitation synchronous motor for excitation control system, this paper puts forward excitation current control strategy for different working conditions. The excitation control system automatically determines when to pull the motor into synchronization according to the motor speed, and adjusts the motor power factor by adjusting the excitation current. The excitation control system uses a double closed loop control algorithm to keep the terminal voltage of the generator near a given value. When the load of the generator changes, the excitation control system quickly adjusts the magnitude of the excitation current to cope with this change. Maximum guarantee generator output voltage stability. Finally, an excitation control system for brushless synchronous motor is designed and developed. The excitation control system uses the hardware PWM signal of the microcontroller and the discrete digital Pi algorithm to control the brushless excitation synchronous motor by the closed loop control method. The excitation current is controlled accurately, The effectiveness of the excitation control strategy proposed in this paper is verified.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM341

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