Abstract

The three-level converters have an inherent problem of the neutral-point (NP) voltage unbalance due to the split dc-link capacitors. This NP voltage unbalance degrades the output voltage/current waveform quality. A carrier-based discontinuous pulsewidth modulation (CB-DPWM) with NP voltage balancing strategy-that involves the injection of calculated zero-sequence voltages to the original modulation signal-is implemented for the three-level T-type converter in this article. The zero-sequence voltages are determined from the space-vector synthesis of the converter output voltages. This method allows the determination of the zero-sequence voltages with few judgment conditions. Unlike the space-vector-based discontinuous pulse width modulation, the CB-DPWM is easier to realize in practical applications. Moreover, the proposed CB-DPWM can also be directly used in parallel systems, which can suppress NP voltage ripples and circulating currents simultaneously by a coordinated strategy. The efficacy of the proposed method in balancing the NP voltage in single and parallel systems is demonstrated by simulations and experiments.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.