Torque tripple has significant effect on performance of permanent magnet brushless DC motor. This paper presents a mathematical model built for such a motor, the analysis of torque tripple for a brushless DC motor wit...Torque tripple has significant effect on performance of permanent magnet brushless DC motor. This paper presents a mathematical model built for such a motor, the analysis of torque tripple for a brushless DC motor with sinusoidal flux distribution, which is verified by torque tripple experiments run with a test motor, and equations developed for torque tripple resulting from different sator current errors.展开更多
A power system structure composed of a brushless DC motor and a cycloidal reducer for electric balanced vehicle has been proposed, and the temperature of important components in this structure would be discussed. The ...A power system structure composed of a brushless DC motor and a cycloidal reducer for electric balanced vehicle has been proposed, and the temperature of important components in this structure would be discussed. The loss generated by the cycloid reducer is negligible, it’s only need to analyze the thermal field of motor. Since the temperature change will affect the material properties of the target motor, the electromagnetic and temperature fields, involved in the motor, are selected for coupling calculation to determine whether the final temperature distribution can meet the requirements of vehicle for use.展开更多
Rising concern in environmental issues on global scale has made energy saving in powered equipment a very important subject.In order to improve the energy efficiency and driving range of a motor hoist,a regenerative b...Rising concern in environmental issues on global scale has made energy saving in powered equipment a very important subject.In order to improve the energy efficiency and driving range of a motor hoist,a regenerative braking system is designed and discussed.The system takes a unique ultracapacitor-only approach to energy storage system.The bi-directional bride DC?DC converter which regulates current flow to and from the ultracapacitor operates in two modes:boost and buck,depending on the direction of the flow.In order to provide constant input and output current at the ultracapacitor,this system uses a double proportional-integral(PI) control strategy in regulating the duty cycle of PWM to the DC?DC converter.The permanent magnet synchronous motor(PWSM) drive system is also studied.The space vector pulse width modulation(SVPWM) technique,along with a two-closed-loop vector control model,is adopted after detailed analysis of PMSM characteristics.The overall model and control strategy for this regenerative braking system is ultimately built and simulated under the MATLAB and Simulink environment.A test platform is built to obtain experimental results.Analysis of the results reveals that more than half of the gravitational potential energy can be recovered by this system.Simulation and experimentation results testify the validity of the double PI control strategy for interface circuit of ultracapacitor and SVPWM strategy for PMSM.展开更多
The torque-speed characteristics of brushless motor having an interior permanent magnet rotor and a sinusoidal back-emf waveform are compared experimentally when it is operated in brushless AC(BLAC) mode and brushless...The torque-speed characteristics of brushless motor having an interior permanent magnet rotor and a sinusoidal back-emf waveform are compared experimentally when it is operated in brushless AC(BLAC) mode and brushless DC (BLDC) modes with both 2-phase,120° conduction(BLDC-120) and 3-phase,180° conduction(BLDC-180).Particular emphasis is on high-speed,six-step voltage controlled,flux-weakening operation.It is shown that for EV/HEV applications,even for interior PM brushless motors which have sinusoidal back-emf waveforms,in order to achieve maximum torque per ampere capability over wide operation speed range,it is advantageous to employ a hybrid operation mode-BLAC operation in the constant torque region and six-step voltage control(BLDC-180 operation,together with current phase control) in the flux-weakening region.展开更多
文摘Torque tripple has significant effect on performance of permanent magnet brushless DC motor. This paper presents a mathematical model built for such a motor, the analysis of torque tripple for a brushless DC motor with sinusoidal flux distribution, which is verified by torque tripple experiments run with a test motor, and equations developed for torque tripple resulting from different sator current errors.
文摘A power system structure composed of a brushless DC motor and a cycloidal reducer for electric balanced vehicle has been proposed, and the temperature of important components in this structure would be discussed. The loss generated by the cycloid reducer is negligible, it’s only need to analyze the thermal field of motor. Since the temperature change will affect the material properties of the target motor, the electromagnetic and temperature fields, involved in the motor, are selected for coupling calculation to determine whether the final temperature distribution can meet the requirements of vehicle for use.
基金supported by National Key Technology Research and Development Program of China (Grant No. 2007BAF10B00)
文摘Rising concern in environmental issues on global scale has made energy saving in powered equipment a very important subject.In order to improve the energy efficiency and driving range of a motor hoist,a regenerative braking system is designed and discussed.The system takes a unique ultracapacitor-only approach to energy storage system.The bi-directional bride DC?DC converter which regulates current flow to and from the ultracapacitor operates in two modes:boost and buck,depending on the direction of the flow.In order to provide constant input and output current at the ultracapacitor,this system uses a double proportional-integral(PI) control strategy in regulating the duty cycle of PWM to the DC?DC converter.The permanent magnet synchronous motor(PWSM) drive system is also studied.The space vector pulse width modulation(SVPWM) technique,along with a two-closed-loop vector control model,is adopted after detailed analysis of PMSM characteristics.The overall model and control strategy for this regenerative braking system is ultimately built and simulated under the MATLAB and Simulink environment.A test platform is built to obtain experimental results.Analysis of the results reveals that more than half of the gravitational potential energy can be recovered by this system.Simulation and experimentation results testify the validity of the double PI control strategy for interface circuit of ultracapacitor and SVPWM strategy for PMSM.
文摘The torque-speed characteristics of brushless motor having an interior permanent magnet rotor and a sinusoidal back-emf waveform are compared experimentally when it is operated in brushless AC(BLAC) mode and brushless DC (BLDC) modes with both 2-phase,120° conduction(BLDC-120) and 3-phase,180° conduction(BLDC-180).Particular emphasis is on high-speed,six-step voltage controlled,flux-weakening operation.It is shown that for EV/HEV applications,even for interior PM brushless motors which have sinusoidal back-emf waveforms,in order to achieve maximum torque per ampere capability over wide operation speed range,it is advantageous to employ a hybrid operation mode-BLAC operation in the constant torque region and six-step voltage control(BLDC-180 operation,together with current phase control) in the flux-weakening region.