ABSTRACT
This chapter introduces soft-switching technique in DC/AC inverters. There are numerous ways of implementing soft-switching methods, such as zero voltage switching and zero current switching, to reduce the switching losses and to increase efficiency for different multilevel inverters. The brushless DC motor has been widely used in industrial applications because of its low inertia, fast response, high power density, and high reliability, because of which it is maintenance-free. The resonant circuit consists of three auxiliary switches, one resonant inductor, and one resonant capacitor. The auxiliary switches are controlled at a certain instant to obtain resonance between transformer and capacitor. The design of the resonant circuit is to determine the resonant capacitor, resonant inductor, and the switching instants of auxiliary switches. The inductor power losses of the inverter are considerable as current always flows in the inductor. The operation of the inverter can be divided into pulse-width-modulation (PWM) operation and non-PWM operation.
