A five leg inverter (FLI) control is incorporated to drive two independent rated permanent magnet synchronous motors (PMSMs) for automotive applications. Literature evidences many attempts of employing the FLI for con...A five leg inverter (FLI) control is incorporated to drive two independent rated permanent magnet synchronous motors (PMSMs) for automotive applications. Literature evidences many attempts of employing the FLI for controlling two general purpose/special motors, where variety of modulation techniques has been practiced for performance enhancement. Also in these cases one leg of inverter is common to both the motors. The expanded two arm modulation (ETAM) has been generally engaged in FLI. In ETAM the percentage voltage utilization factor (VUF) is calculated based on “α<sub>max</sub>”, where “α<sub>max</sub>” is the maximum modulation index and equal to and hence it restricts the VUF to 50%. This makes the FLI drives to use the dc link in inefficient way, which is due to the fact that conventional ETAM works with voltage reference. This paper modifies the ETAM in an ingenious way to improve the VUF further through current reference. In addition, the developed current reference expanded two arm modulation (CRETAM) minimizes the current harmonics and torque ripple as well. A detailed comparison of the CRETAM with the conventional ETAM and the competent digital counterpart, space vector pulse width modulation (SVPWM), is also presented. The enhancement in VUF, torque ripple minimization and current total harmonic distortion (THD) reduction are found in the MATLAB based simulation results.展开更多
The move from internal combustion engine vehicles to electric vehicles is happening rapidly,which demands a stepwise change in priorities for the vehicle design process with rational consideration of emerging technolo...The move from internal combustion engine vehicles to electric vehicles is happening rapidly,which demands a stepwise change in priorities for the vehicle design process with rational consideration of emerging technologies.This paper focuses on the efficiency of a particular form of high fixed-ratio(15:1)traction drive speed reducer.This is suitable for use in conjunction with a high-speed electric motor for automotive applications.A general discussion of the characteristics of other fixed-ratio traction drives is provided followed by an analysis of underlying efficiency issues.The paper presents details of the speed reducer prototype called a"Silk Drive"and the vehicle for which it was designed.Data from laboratory testing of the prototype are presented,and an efficiency map for the transmission is developed.The efficiency map and vehicle parameters are used in a simulation to determine the overall transmission efficiency for the world harmonized light vehicles test cycles(WLTC)class 3b drive cycle.The importance of transmission efficiency at low power levels,in specific input speed and torque regions,is demonstrated using a novel method for identifying those speed torque regions that most strongly affect overall efficiency.The method applies to all drivetrain components and pinpoints those regions that need to be the focus in the optimal design of such components.This paper presents evidence that the efficiency of zero-spin,fixed-ratio traction drives is similar to that of conventional gear drives.展开更多
文摘A five leg inverter (FLI) control is incorporated to drive two independent rated permanent magnet synchronous motors (PMSMs) for automotive applications. Literature evidences many attempts of employing the FLI for controlling two general purpose/special motors, where variety of modulation techniques has been practiced for performance enhancement. Also in these cases one leg of inverter is common to both the motors. The expanded two arm modulation (ETAM) has been generally engaged in FLI. In ETAM the percentage voltage utilization factor (VUF) is calculated based on “α<sub>max</sub>”, where “α<sub>max</sub>” is the maximum modulation index and equal to and hence it restricts the VUF to 50%. This makes the FLI drives to use the dc link in inefficient way, which is due to the fact that conventional ETAM works with voltage reference. This paper modifies the ETAM in an ingenious way to improve the VUF further through current reference. In addition, the developed current reference expanded two arm modulation (CRETAM) minimizes the current harmonics and torque ripple as well. A detailed comparison of the CRETAM with the conventional ETAM and the competent digital counterpart, space vector pulse width modulation (SVPWM), is also presented. The enhancement in VUF, torque ripple minimization and current total harmonic distortion (THD) reduction are found in the MATLAB based simulation results.
文摘The move from internal combustion engine vehicles to electric vehicles is happening rapidly,which demands a stepwise change in priorities for the vehicle design process with rational consideration of emerging technologies.This paper focuses on the efficiency of a particular form of high fixed-ratio(15:1)traction drive speed reducer.This is suitable for use in conjunction with a high-speed electric motor for automotive applications.A general discussion of the characteristics of other fixed-ratio traction drives is provided followed by an analysis of underlying efficiency issues.The paper presents details of the speed reducer prototype called a"Silk Drive"and the vehicle for which it was designed.Data from laboratory testing of the prototype are presented,and an efficiency map for the transmission is developed.The efficiency map and vehicle parameters are used in a simulation to determine the overall transmission efficiency for the world harmonized light vehicles test cycles(WLTC)class 3b drive cycle.The importance of transmission efficiency at low power levels,in specific input speed and torque regions,is demonstrated using a novel method for identifying those speed torque regions that most strongly affect overall efficiency.The method applies to all drivetrain components and pinpoints those regions that need to be the focus in the optimal design of such components.This paper presents evidence that the efficiency of zero-spin,fixed-ratio traction drives is similar to that of conventional gear drives.
