The nonlinear voltage distortion effect of an extended IGBT turn-off time in sinusoidal PWM VSI applications

A new dasiaextended turn-off timepsila compensation parameter is introduced to overcome the low-current nonlinear voltage distortion effect in IGBT inverters. The compensation technique uses datasheet parameters in conjunction with an analytical approach to model the low-current switching characteristics of an IGBT. As a result, output voltage amplitude is accurately controlled and low-order voltage harmonics are reduced resulting in reduced current distortion, reduced power loss and, in motor drive applications, reduced torque ripple. The compensation technique can be easily integrated into a conventional dasiaaverage valuepsila type compensator without the need for significant modification and without the need for experimentally intensive lookup tables.