DC-link Ripple Reduction in a DPWM-Based Two-Level VSI
This paper proposes a new method to reduce the ripple current of the DC-link capacitor in a two-level voltage source inverter (VSI), with a discontinuous pulse-width modulation (DPWM). In real applications, a capacitor block is very bulky, due to the parallel connection of several capacitors that share the value of the ripple current. Hence, it contributes signiﬁcantly to the volume and weight of the whole system. Conventional DPWM is used to minimize the amount of switching for the power transistors, therefore, reducing stress and power loss. This leads to increased efﬁciency and reliability of the system. Nevertheless, the reduction of the DC link ripple current is still not optimal. Therefore, the proposed method introduces a PWM phase-shift technique to provide further reduction of the DC-link ripple current in a DPWM-based VSI. The efﬁcacy of the proposed method is conﬁrmed by simulation and experimental results.