Anatolii Tcai, “Discontinuous PWM Method with Reduced DC-link Ripple Current in Back-to-back Converters,” 아주대학교 공학석사 학위 논문, 2018. > Paper

This paper introduces a novel discontinuous pulse width modulation (DPWM) method to minimize the dc-link ripple current in back-to-

back converters. DPWM is used in power converters to curtail the stress on the switching devices, therefore, extending the lifespan. 

However, as the conventional DPWM is used in a back-to-back topology, the ripple current of the dc-link severely increases during the 

regions when the power switches are clamped to the dc-bus. Furthermore, the dc-link ripple current reaches the amplitude value when 

the power switches of both converters are clamped to different dc-link buses. As a result, the life-span of the dc-link capacitor 

decreases as it endures more stress.To surmount this issue, the reference voltages should be obtained considering the intervals with 

the increased ripple current of the dc-link. It is achieved by adjusting the zero-sequence component to match the clamping states of 

both inverters. The efficacy and performance of the proposed method are demonstrated via the PSIM simulation and the experimental 

results.