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Title: A Control Scheme Based on Lyapunov Function for Cascaded H-Bridge Multilevel Active Rectifiers
The cascaded H-bridge multilevel active rectifier is a prominent converter configuration. It presents compelling advantages, including high adjustability for a number of applications, such as in solid-state transformers, traction applications, medium and high power motor drives and battery chargers. However, when the H-bridge is operating under an unbalanced load and asymmetrical voltage conditions, it becomes important to design advanced control strategies to maintain the stability of the system. In this study, a Lyapunov-function based control method is proposed for controlling the single-phase cascaded H-bridge active rectifier to achieve global asymptotic stability. A capacitor voltage feedback is added to the conventional Lyapunov-function based stabilizing control method to minimize the resonance of the LCL filter. Additionally, a Proportional-Resonant (PR) control approach is adopted to obtain the reference current signal. This increases the robustness of the current control scheme. A DC voltage balancing control procedure is also employed to prevent the unbalanced DC voltage conditions among the H-bridges. The DC voltage is controlled via a PI controller. The capability of the control approach is verified with simulation and experimental studies.
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Publication Date:
Journal Name:
2020 IEEE Applied Power Electronics Conference and Exposition (APEC)
Page Range or eLocation-ID:
2021 to 2026
Sponsoring Org:
National Science Foundation
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