Performance Enhancement Method for PWM VSI Drivers in Low Frequencies

摘要

A dead time is essential for an inverter to prevent short circuit condition in a leg. However, when it is included the output voltage volt-seconds are lost or gained depending on the output current direction. Due to this, there is a deviation of expected voltage. Inverter consists of IGBTs where each has IGBT saturation voltage and diode threshold voltage. At low voltage, dead time distortion and device voltage drop cause torque pulsation. In this paper a simple but an accurate dead time distortion compensation method is used. Also a voltage boost is proposed for device voltage drop. Using these compensation methods, torque pulsation is reduced.