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
文章基于RANS方程,对计及自由面影响的双桨转动情况下的舰船旋臂试验(RAT)粘性流场数值模拟方法进行了研究。在旋臂试验的数值模拟中,根据旋臂试验的特点,采用分区混合网格,结合MRF方法和滑移网格方法,解决船体圆运动及螺旋桨定轴旋转...文章基于RANS方程,对计及自由面影响的双桨转动情况下的舰船旋臂试验(RAT)粘性流场数值模拟方法进行了研究。在旋臂试验的数值模拟中,根据旋臂试验的特点,采用分区混合网格,结合MRF方法和滑移网格方法,解决船体圆运动及螺旋桨定轴旋转运动的叠合难题。文中以ITTC推荐的MARIN model no.7967船模为对象,对其在四组转动半径下的旋臂试验进行了数值计算,并将结果与权威水池试验结果进行了对比,吻合良好。文中提出的方法可获得全附体船模旋转流场水动力性能参数,可以较真实地模拟其流场特性,获取包括船—舵—桨干扰在内的流场信息。该文的工作是可行的、有效的,可为深入研究舰船自由旋回试验及非定常操纵运动的数值模拟提供基础。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.
文摘文章基于RANS方程,对计及自由面影响的双桨转动情况下的舰船旋臂试验(RAT)粘性流场数值模拟方法进行了研究。在旋臂试验的数值模拟中,根据旋臂试验的特点,采用分区混合网格,结合MRF方法和滑移网格方法,解决船体圆运动及螺旋桨定轴旋转运动的叠合难题。文中以ITTC推荐的MARIN model no.7967船模为对象,对其在四组转动半径下的旋臂试验进行了数值计算,并将结果与权威水池试验结果进行了对比,吻合良好。文中提出的方法可获得全附体船模旋转流场水动力性能参数,可以较真实地模拟其流场特性,获取包括船—舵—桨干扰在内的流场信息。该文的工作是可行的、有效的,可为深入研究舰船自由旋回试验及非定常操纵运动的数值模拟提供基础。
