电流源逆变器复矢量解耦与前馈解耦联合降阶控制策略研究

Joint Reducer-Order Control Strategy of Complex Vector Decoupling and Feedforward Decoupling for Current Source Inverters

电流源逆变器输出侧需添加电容器对输出斩波电流进行滤波,导致电流源逆变器电机驱动系统控制模型具有系统阶次高、存在谐振点、旋转坐标系下模型耦合严重等问题。针对上述问题,以降阶控制为主要目的,提出了复矢量解耦与前馈解耦联合降阶控制策略。针对电流源逆变器的复矢量模型,引入电机电流前馈消除模型中电机电流耦合项,在此基础上,使用复矢量解耦策略,针对二阶串联模型设计带有耦合误差项的比例积分控制器,消除常规控制器中高阶模型导致的闭环系统谐振,简化闭环模型,实现系统的解耦与降阶。同时,该控制器具有结构与参数整定简单的优点,通过稳定性分析验证了所提闭环电流控制器的可行性。以一台3 kW永磁同步电机为对象进行仿真,并与传统控制策略、双闭环控制策略进行对比验证。结果表明,所提控制策略在降低模型阶次、简化控制器设计的同时,相较于传统控制策略解耦合能力更强,在阶跃响应与转速耦合作用下表现出更强稳定性,电流在阶跃信号作用下均没有发生振荡。

The output side of the current source inverter needs to add a capacitor filter to eliminate the output chopping current,which leads to high model order,resonance points,and serious coupling issues of the current source inverter in the motor driver rotating coordinate system.A joint reducer-order control strategy of complex vector decoupling and feedforward decoupling is proposed.The basic idea is adding a motor current feedforward to eliminate the motor current coupling term in the complex vector model of the current source inverter.Based on this,a proportional integral controller with coupling error term is designed for the model by using complex vector decoupling strategy.It eliminates the closed-loop system resonance caused by the high-order model in the conventional controller,simplifies the closed-loop model,and realizes the decoupling and order reduction of the system.The controller has the advantages of simple structure and parameter tuning.The feasibility of the proposed closed-loop current controller is verified through stability analysis.Finally,a 3 kW permanent magnet synchronous motor is simulated and compared with conventional control strategy and dual closed-loop control strategy for verification.The results show that the control strategy proposed in this paper has a stronger decoupling ability compared with traditional control strategy,while reducing the model order and simplifying controller design.It exhibits stronger stability under the coupling of step response and speed,and the motor speed and current do not oscillate under the action of step signals.