带 LC 滤波器的永磁同步电机控制系统设计毕业论文
2021-11-20 22:19:10
论文总字数:22073字
摘 要
一般而言,永磁同步电机较直流电动机及感应电机小、调速效果较佳,并可达到高功率密度高转矩惯量。近年来,永磁同步电动机在航空航天、机器人、军事国防等领域的应用越来越广泛,常用于构建高精度的运动控制系统。在永磁同步电动机控制系统中,速度控制的效果优劣在很大程度上决定了系统的静态稳定性和电机的转速、转矩输出效果,因此需要速度控制器可以对永磁同步电机的转速有良好的控制性能。速度控制主要是对电机侧电流和电机转速进行双矢量闭环反馈控制。随着电力电子器件高频化的发展,当永磁同步电动机直接由PWM逆变器驱动时,电缆的长期效应不容忽视。过电压问题将对电动机的正常运行造成严重威胁,并有可能引发绝缘安全问题。故在逆变器侧加LC滤波器。加入滤波器,可以滤除开关电压谐波,从而使输出电压呈近似正弦分布。然而,电容支路在电路中相当于和永磁同步电机并联。逆变器侧电流与电机侧电流存在的差值将会使电机转速的控制出现偏差。通过结合基波电容电流补偿进行逆变侧电流反馈的控制方法(ICF)对电机侧三相电流进行控制。其中电容电流的基波分量是通过电容电压微分算法基于二阶广义积分器进行估计采样。
为了提高运动控制系统的控制性能,研究的方向是通过分析受控对象建立更加吻合的模型或者是采用控制性能更好的控制器。分数微积分理论的不断成熟和各种学科的不断发展,不断在实际生产中的应用,可以使用分数微积分来设计一个控制器的运动控制系统,可以实现理想的目标,从而达到更好的运动控制系统的性能。采用分数阶控制器对永磁同步电机进行矢量控制。
为了使调速系统满足严格的性能要求,发挥分数阶比例积分微分控制器调节更加灵活,参数设置要求更高的特点,建立了永磁同步电动机控制系统分数阶模型。通过对电机侧电流的控制仿真,研究了采用分数阶控制器的电机系统的动态响应性能。并通过仿真分析永磁同步电机的启动过程和拖动阶跃负载的运行情况。通过系统仿真结果可知,在保证系统稳定的前提下采用分数阶速度控制器的系统比采用整数阶PID控制器的系统具有更好的暂态性能和控制效果。
关键词:永磁同步电机 LC滤波器 逆变器侧电流控制 PID控制 分数阶PID控制
Abstract
In general, PMSM is smaller than dc motor and induction motor, has better speed regulation effect, and can achieve high power density and high torque inertia.In recent years, permanent magnet synchronous motors (PMSM) have been widely used in aerospace, robotics, military defense and other fields, and are often used to build high-precision motion control systems.In the control system of permanent magnet synchronous motor (PMSM), the effect of speed control largely determines the static stability of the system and the output effect of the motor speed and torque. Therefore, it is necessary for the speed controller to have a good control performance of the PMSM speed.Speed control is mainly based on double vector closed-loop feedback control of motor side current and motor speed.With the development of high-frequency power electronic devices, when PMSM is driven directly by PWM inverter, the long-term effect of cable can not be ignored.The over-voltage problem will pose a serious threat to the normal operation of the motor and may cause insulation safety problems.In order to solve this problem, the method of adding LC filter on the inverter side is needed.With the addition of a filter, the switching voltage harmonics can be removed, so that the output voltage is approximately sinusoidal.However, the capacitor branch in the circuit is equivalent to a permanent magnet synchronous motor in parallel.The difference between the inverter side current and the motor side current will cause the deviation of the motor speed control.The three-phase current on the motor side is controlled by the control method of inverter current feedback (ICF) based on the base wave capacitor current compensation.The fundamental wave component of capacitive current is estimated and sampled by the capacitive voltage differential algorithm based on the second-order generalized integrator.
In order to improve the control performance of the motion control system, the research direction is to build a more consistent model or adopt a controller with better control performance by analyzing the controlled objects.With the constant maturity of fractional calculus theory and the continuous development of various disciplines, it is possible to design a motion control system of a controller with fractional calculus, which can achieve the ideal goal and thus achieve better performance of the motion control system.The fractional order controller is used for vector control of PMSM.
In order to make the speed control system meet the strict performance requirements, the fractional order model of the permanent magnet synchronous motor control system is established by taking advantage of the characteristics of the fractional order proportional integral and differential controller which is more flexible in regulation and higher in parameter setting.The dynamic response performance of the motor system with fractional order controller is studied through the control simulation of the motor side current.The starting process of PMSM and the operation of dragging step load are analyzed by simulation.Through the system simulation results, it can be seen that the system using fractional order speed controller has better transient performance and control effect than the system using integer order PID controller under the premise of ensuring system stability.
Keywords: Permanent magnet synchronous machine;LC filter;Inverter side current feedback control;PID control;Fractional order PID control;
目录
摘要 II
Abstract III
第1章 绪论 1
1.1永磁同步电机发展现状 1
1.2带滤波器的必要性 2
1.3分数阶控制的研究现状 2
1.4电动机矢量控制 3
1.5章节内容安排 3
第2章 带LC滤波器的永磁同步电机系统 5
2.1永磁同步电机系统模型 5
2.2 逆变器侧电流反馈控制及其稳定性 6
2.2.1逆变器参数稳定条件 7
2.2.2电流环调节器参数选取的稳定条件 8
2.3本章小结 9
第3章永磁同步电机基本方程及矢量控制 10
3.1引言 10
3.2三相定子坐标系下的数学模型 10
3.3矢量控制思想 11
3.4 空间矢量脉冲宽度调制 18
3.4.1电压空间矢量定义 18
3.4.2 SVPWM调制 18
3.5电容基波电流值采样 22
3.5.1 SOGI 微分算法原理 23
3.5.2 滤波电容基波电流 24
3.6本章小结 24
第4章系统仿真分析 25
4.1系统控制框图 25
4.2整数阶PID控制研究 26
4.3分数阶PID控制研究 28
4.4本章小结 30
第5章 结论和展望 31
参考文献 32
致谢 33
第1章 绪论
1.1永磁同步电机发展现状
随着交流电力系统的发展,交流异步电动机越来越多的被用作驱动各种设备的运转。交流异步电动机相对来说技术成熟,应用广泛,且运行可靠价格低廉时期主要优点。但交流异步电机速度控制效果差,转速不稳定,启动转矩小,启动过程产生旋转磁场要从电网中吸收无功功率,导致电网功率因数降低甚至可能影响电压水平,增加了输电线路和电网的损耗。但在实际生产中异步电动机长期以来一直是电力拖动的主要动力。 [1][1]
近五十年来,永磁同步电动机相关技术获得了长远发展,一些重要因素如永磁材料有了极大的飞跃。可将技术发展分为如下几方面:1.新型永磁材料的发展应用简化了同步电机的结构。新型永磁材料取代了电激磁磁极,省去转子滑环实现了无刷电机,大大简化了结构2.电力电子器件和技术的发展促进了永磁同步电动机控制和应用。可变频电源的成熟发展应用,解决了同步电机不能自启动的问题。3.永磁同步电动机控制集成电路借助于规模集成电路和计算机技术的发展而到了进一步发展。[2][2][3][3]
请支付后下载全文,论文总字数:22073字