The flux-weakening performance of a permanent magnet brushless AC drive was investigated using both floating-point and fixed-point DSP controllers. A significant current oscillation was observed when the drive was ope...The flux-weakening performance of a permanent magnet brushless AC drive was investigated using both floating-point and fixed-point DSP controllers. A significant current oscillation was observed when the drive was operated at high-speed in the flux-weakening mode with the fixed-point DSP. The investigation showed that this was due to the on-line compensation of the winding resistance voltage drop and quantisation errors associated with the fixed-point architecture of the DSP. A simple look-up table scheme is proposed to eliminate the oscillation and to achieve extended flux-weakening capability.展开更多
This paper employs an extended Kalman filter (EKF) to estimate the rotor position and speed of a vector controlled surface-mounted permanent magnet (PM) brushless AC (BLAC) motor from measured terminal voltages and cu...This paper employs an extended Kalman filter (EKF) to estimate the rotor position and speed of a vector controlled surface-mounted permanent magnet (PM) brushless AC (BLAC) motor from measured terminal voltages and currents only. Both full-order and simplified EKFs are employed and their simulated performance capabilities are compared. Excellent agreement is achieved between estimated and commanded results. The EKF is also employed to identify the stator flux-linkage due to the PMs, which is influenced by temperature variation and magnetic saturation.展开更多
作动器系统作为直升机结构响应主动控制系统(active control of structure response, ACSR)执行元件的重要核心部件,其控制性能直接关系到振动的抑制效果。研制了一套基于永磁无刷直流电机驱动的离心式作动器原理样机,详细阐述了系统组...作动器系统作为直升机结构响应主动控制系统(active control of structure response, ACSR)执行元件的重要核心部件,其控制性能直接关系到振动的抑制效果。研制了一套基于永磁无刷直流电机驱动的离心式作动器原理样机,详细阐述了系统组成及工作原理,论述了作动器输出力频率、幅值和相位的调节方式,建立了偏心块的输出力方程,选取了MAXON公司生产的EC60 flat 411 678无刷电机作为驱动源。设计了作动器伺服控制系统,针对功率驱动中的隔离直流电源、自举二极管、自举电容、电流驱动能力及母线支撑电容等关键参数进行了详细设计。通过实验验证,电机转速误差最终被控制为1%以内,位置响应时间小于50 ms,振动抑制在0.001 5g(g为重力加速度)以下,取得了较好的控制性能,为离心式作动器系统在直升机平台的应用奠定了基础。展开更多
文摘The flux-weakening performance of a permanent magnet brushless AC drive was investigated using both floating-point and fixed-point DSP controllers. A significant current oscillation was observed when the drive was operated at high-speed in the flux-weakening mode with the fixed-point DSP. The investigation showed that this was due to the on-line compensation of the winding resistance voltage drop and quantisation errors associated with the fixed-point architecture of the DSP. A simple look-up table scheme is proposed to eliminate the oscillation and to achieve extended flux-weakening capability.
文摘This paper employs an extended Kalman filter (EKF) to estimate the rotor position and speed of a vector controlled surface-mounted permanent magnet (PM) brushless AC (BLAC) motor from measured terminal voltages and currents only. Both full-order and simplified EKFs are employed and their simulated performance capabilities are compared. Excellent agreement is achieved between estimated and commanded results. The EKF is also employed to identify the stator flux-linkage due to the PMs, which is influenced by temperature variation and magnetic saturation.