| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance the upper limit of the output torque from a motor without affecting the voltage of a capacitor as a drive power source. <P>SOLUTION: A DC power source 40 is connected between the neutral points of the three-phase coils 24 and 26 of two Y connections without discrepancy of winding angle which are supplied severally with three-phase AC power from two inverter circuits 30 and 32 sharing a positive electrode bus 34 and a negative electrode bus 36, and also a capacitor 38 is connected between the positive electrode bus 34 and the negative electrode bus 36. The supply of the three-phase AC power is performed by the PWM control by the comparison between modulated waves, where tertiary harmonics having the same amplitude and frequency mutually in the same phase are superposed each on the three-phase modulated waves having the same amplitude and frequency mutually in the same phase, and triangular waves. Consequently, it is possible to enhance the upper limit of the output torque from a motor by reducing the amplitude maximum value of the modulated waves without oscillating the potential difference between the neutral points, that is, the voltage of the capacitor. <P>COPYRIGHT: (C)2004,JPO |
