基于单电流调节器的永磁同步电机深度弱磁控制及模式切换控制策略

Deep Flux Weakening Control and Mode Switching Control Strategy of Permanent Magnet Synchronous Motor Based on Single Current Regulator

为解决传统双电流调节器弱磁控制策略因交叉耦合和电流调节器饱和导致的系统不稳定问题,提高电流动态响应速度,本文提出一种稳定的永磁同步电机深度弱磁控制策略——基于电压相角的改进型单电流调节器弱磁控制及模式切换控制策略。该控制策略集成了动态性能优异、控制结构简单、不依赖电机参数、电压利用率高和可移植性强等优点。在分析了不同单电流调节器的稳定运行范围后,根据系统控制需求的不同,规划了不同的电流轨迹,设计了不同单电流调节器弱磁控制策略,优化改进了恒转矩区和弱磁区切换条件,确定了恒转矩区和弱磁区切换时保持电压相角不变的关键,提出了不同单电流调节器切换时,可根据控制需求的不同,设计不同的切换方法,但须确保切换时交轴电压保持不变的切换关键,使控制策略便于工程应用。仿真和实验验证了所提方法的稳定深度弱磁能力和切换控制策略的有效性,最终实现了6.3倍深度弱磁控制和弱磁区不同单电流调节器在电动工况和发电工况下的平滑切换。

In order to solve the problem of system instability caused by cross-coupling and current regulator saturation of traditional dual-current regulator flux weakening control strategy and improve the current dynamic response speed,this paper proposes a stable deep flux weakening control strategy for permanent magnet synchronous motor,i.e.,the improved single-current regulator flux weakening control based on voltage phase angle and mode switching control strategy.The control strategy integrates the advantages of excellent dynamic performance,simple control structure,independent of motor parameters,high voltage utilization and high portability.After analyzing the stable operation range of different single current regulators,different current trajectories are planned and different single current regulator flux weakening control strategies are designed according to different system control requirements.The switching conditions of constant torque region and flux weakening region are optimized and improved,and the key to keep the voltage phase angle constant for switching of constant torque region and flux weakening region is determined.It is proposed that different switching methods can be designed according to different control requirements when different single current regulators are switched,but the switching key of keeping the q-axis voltage constant must be ensured to make the control strategy easy for engineering applications.Simulations and experiments have verified the effectiveness of the proposed method in stabilizing the deep flux weakening capability and switching control strategy,which finally achieves 6.3 times deep flux weakening control and smooth switching of different single current regulators in the flux weakening region under electric and power generation conditions.