An investigation of new type robust servo control system by using sqirrel-cage induction motor

本研究的目的是开发一种电压源逆变鼠笼式感应电机伺服系统，该系统通过矢量控制将转矩与指令之间的传递函数简化为直流电动机。在该系统中，研究了对负载和系统参数变化的鲁棒性改进。通过分析和实验得到的结果如下：1。系统设计与分析：将模型跟踪控制器应用于PWM逆变式异步电机伺服系统。采用最优调节器理论设计控制器增益，使指定的性能指标最小化。为了研究机床参数变化对系统的影响，利用小位移理论建立了系统的线性模型。研究了极、零点轨迹和瞬态响应。实验设备：采用微处理器V40实现模型跟随控制和矢量控制。软件采用汇编语言描述，减少了计算时间。为了实现数据传输、控制程序的调试和状态变量的显示，开发了一种控制器监视器。分析和实验结果表明：模型跟随控制在以下几个方面优于传统的PI（比例加积分）控制：(1)对于指定的权重常数，模型跟随控制器的最优增益容易确定。(2)降低了指令值变化的超调量。(3)通过选择较大的权重常数值，使系统对负载转矩和设备参数的变化具有鲁棒性。

The purpose of this investigation is to develop a voltage source inverterfed squirrel-cage induction motor servo system in which the transfer function between the torque and its command is simplified like a DC motor by the vector control. In this system, an improvement of robustness for the change of load and system parameters is studied. The results obtained by the analysis and experiment are as follows:1. System design and analysis: A model following controller is adapted to a PWM inverter-fed induction motor servo system. The gains of controller is designed by using the optimal regulator theory to minimize the specified performance index. In order to study the influence of machine parameter change, a linear model of the system is derived by using a small displacement theory. The trajectories of poles and zeros and the transient responses are studied.2. Experimental equipment: The microprocessor V40 is used for the implementation of the model following control and the vector control. The software is described by the assembly language to reduce the computation time. For the data transmission, the debugging of control program and the display of state variables, a controller monitor is developed.3. Analytical and experimental results: The model following control is superior to the conventional PI ( proportional plus integral ) control with regard to following points: (1) The optimal gains of the model following controller are easily determined for the specified weighting constant. (2) The overshoot for the change of command values is decreased. (3) By selecting a large value of the weighting constant, the system is robust for the change of load torque and plant parameters.