混合励磁同步电机的低速控制策略研究

Research on Low Speed Control Strategy of Hybrid Excitation Synchronous Machines

为提高混合励磁同步电机低速时的带载能力,减小负载扰动以及变速运动对控制系统的影响,提出了一种基于负载转矩观测器的励磁电流给定策略与q轴电流前馈补偿策略的混合控制策略。采用降阶观测器在线辨识负载转矩,将辨识后的负载转矩作为混合励磁同步电机是否需要提高转矩输出判断依据之一;同时将辨识后的负载转矩及其变化率作为励磁电流给定输入与q轴电流前馈补偿,进而提高混合励磁同步电机的带载能力,同时也可以克服因负载时变对控制性能的影响。仿真结果表明,提出的低速控制策略可以有效地提高混合励磁同步电机调速系统的动态特性与鲁棒性。

In order to improve the load-bearing ability of the hybrid excitation synchronous machines at low speed and reduce the influence of load disturbance and variable speed motion on the control system,a hybrid control strategy based on load torque observer for excitation current given strategy and q-axis current feedforward compensation strategy is presented.And,a reduced-order observer is used to identify the load torque online.The identified load torque is used as one of the criteria for judging whether the hybrid excitation synchronous motor needs to increase the torque output.At the same time,the identified load torque and its rate are used as the excitation current reference inputs and q-axis current feedforward compensation,which can improve the load-bearing ability of the hybrid excitation synchronous motor.And,the control strategy can overcome the effect of time-varying load on control performance.Simulation results show that the proposed low speed control strategy can effectively improve the dynamic characteristics and enhance the robustness of the hybrid excitation synchronous machines speed control system.