Title :
Two-phase modulation technique for three-level inverter-fed AC drives
Author :
Halász, Sándor ; Huu, Bin T. ; Zakharov, Alexei
Author_Institution :
Dept. of Electr. Machines & Drives, Budapest Tech. Univ., Hungary
fDate :
12/1/2000 12:00:00 AM
Abstract :
Two-phase dipolar and unipolar modulation techniques for three-level three-phase inverters are suggested and compared with conventional three-phase pulsewidth modulation (PWM) techniques. Two-phase PWMs with 60° (0° and ±30° shift) and 120° cycles are investigated from the point of view of harmonic losses, motor voltage spectra, and torque pulsations. It is shown that two-phase dipolar PWMs have no advantages in comparison with three-phase PWMs, while two-phase unipolar PWMs-in contrast with three-phase PWMs-considerably decrease the motor harmonic losses and torque pulsations in the whole motor voltage region. At the same time, the inverter neutral point control requires reversing to three-phase PWM technique for the duration of the control.
Keywords :
AC motor drives; PWM invertors; losses; torque; dipolar modulation techniques; harmonic losses; inverter neutral point control; motor harmonic losses decrease; motor voltage spectra; three-level inverter-fed AC drives; three-level three-phase inverters; three-phase pulsewidth modulation techniques; torque pulsations; two-phase modulation technique; unipolar modulation techniques; DC motors; Frequency; Motor drives; Phase modulation; Pulse inverters; Pulse width modulation; Pulse width modulation inverters; Space vector pulse width modulation; Torque; Voltage control;
Journal_Title :
Industrial Electronics, IEEE Transactions on
