PWM strategy of matrix converters for minimizing output voltage harmonics under reducing number of commutations

This paper presents a pulse-width modulation (PWM) strategy that use matrix converters for minimizing output voltage harmonics. The authors have already proposed a PWM strategy to decrease the number of commutations to four in all three phases during a single control period. This paper describes a procedure for further reducing the number of commutations to three in all three phases by permitting one duty cycle to be assigned a value of zero; this procedure is facilitated by using detected output current values to calculate the continuously varying duty cycles in a control period. An algorithm to select duty cycles with minimal output voltage harmonics during these three commutations is also proposed. The effectiveness of the proposed PWM strategy has been verified experimentally.