【作者】 黄志勇；

【导师】 王兴贵；

【作者基本信息】 兰州理工大学 ， 电力电子及电力传动， 2009， 硕士

【摘要】 近年来,低成本、低功率、高性能的无刷直流电动机控制器在民用领域得到了广泛的应用,本文针对以上需求做了相应的研究工作。由于低功率控制器的低成本化主要途径在于使用较少的功率器件,因此本文的切入点放在逆变器主电路拓扑结构的简化上。本文在无刷直流电动机工作原理的基础上,从降低控制系统成本的角度出发,分析了其控制器主电路拓扑结构的机理。通过分析表明,四开关三相拓扑结构是简化电路拓扑结构中最理想的选择。然后详细分析了四开关三相逆变器的工作原理,并指出其本身固有的几个缺点:一是四开关三相逆变器输出电压矢量不对称;二是非可控相绕组在反电动势作用下续流引起的电流波形畸变;三是直流母线电容电压平衡问题。针对前两个问题,文中采用了电流滞环PWM跟踪控制方式并对其进行了改进,对两个可控相绕组中电流进行独立检测和独立控制,从而控制流过电动机三相绕组中的实际电流波形,使其接近理想电流波形。并在此基础上采用了不均衡放电法解决了直流母线电容电压平衡问题。其次为了进一步降低系统成本,该控制器采用了无位置传感器控制。文中采用反电动势转子位置检测方法,并详细分析了其检测原理。最后本文使用电机专控制芯片dsPIC30F3011作为控制核心搭建实验平台并进行实验验证,实验结果表明了上述的理论分析的正确性。因此该低成本四开关三相无刷直流电动机控制器具有工程可行性。更多还原

【Abstract】 Recent year,the Brushless DC Motor controller with low cost application,low power, high properties has been developed widely.In this paper,the simplification and optimization of this kind convers with minimized power switches are discussed.Based on theory of the Brushless DC Motor,analyse the topology structure of main circuit on the view of low coss.In this paper,the best choice is using four-switch three-phase converter.Two faults of four-switch three-phase converter are pointed out based on the principle of operation.One is asymmetric voltage vetor of four-switch three-phase converter. The other is the current aberration of no-controlled phase for the Back EMF.The electromagnetic torque of Brushless DC Motor when the current is anomaly.In this paper, The Current Hysteresis Band PWM control method is adopted for the two problems.It’s theory is controlling the current directly.And the controlled phases are modeled independently to make that the current is like to the ideal wave.To low the cost of the controller,the Back EMF method is adopted to control the Brushless DC Motor.And the Back EMF rotor position detedting method is analysed.In the end,a control systerm is seted up using the dsPIC30F3011 which is produced for motor control.The result of experiment indicate that this systerm is feasible.更多还原