turn on and zero voltage transition (ZCT) turn off together for the main switch of a converter. A new three-phase, three-level dc to dc phase shifted PWM converter is proposed for high power and high input voltage applications. Output voltage is controlled by incorporating phase shift PWM. PWM VSI is widely utilized in ac motor drive applications and at a smaller quantity in controlled rectifi er. Presents an improved PWM current control technique for torque ripple minimization in the low speed mode of operation. The control circuit of the active power fi lter using quadseries voltage-source PWM converters consists of three parts, namely the calculation circuit for the compensating current references, and the control circuit for the dc capacitor voltage. PWM control of dc drive systems is considered as a challenge to the conventional phase controlled systems. Forced commutated converters with PWM control has been developed and offer considerable performance improvements over phase-controlled converters for the same armature inductance. The main topology used in high power dc–dc conversion is the zero voltage switching (ZVS) PWM full bridge converters with phase-shift control. A simple and reliable PWM ac controller which requires only four force-commutated switches and a three-phase diode bridge is proposed for the implementation of the three-phase compensator. A new soft-switched ac/dc PWM converter structure is presented. It is useful for current-fed inverters and PWM rectifi ers. The PWM converter is a potential challenge to the venerable thyristor Graetz bridge at the rectifi er end of the variable-speed ac drive system. The objective of this literature is to report on the successful integration of two identical experimental current-controlled PWM power modulators to form the redfi edinverter pair in the frequency changer for variable-speed ac drive systems. A PWM control technique for ac choppers is proposed that has the advantages of enabling linear control of the fundamental component of the output voltage and complete elimination of its harmonics. 1.1 PWM Technique The PWM dc-to-ac inverter has been widely used in many applications such as uninterruptible power systems (UPS), motor drives, induction heating, etc., due to its circuit simplicity and