Modeling and Control for a Bidirectional Buck-Boost Cascade Inverter

• Published in: IEEE transactions on power electronics Vol. 27; no. 3; pp. 1401 - 1413
• Main Authors: Zhou, Honglin, Xiao, Shuai, Yang, Geng, Geng, Hua
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.03.2012; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Bidirectional control; Bidirectional converter; buck-boost cascade converter; control system; Converters; Electric currents; Electrical engineering. Electrical power engineering; Electrical equipment; Electrical machines; Electronic equipment and fabrication. Passive components, printed wiring boards, connectics; Electronics; Exact sciences and technology; Inductors; inverter; Inverters; Load; modeling; Power electronics, power supplies; Regulation and control; Robust control; Simulation; Switches; Testing. Reliability. Quality control; Topology; Power converter; Bidirectional link; buck-boost cascade converter; Power system stability; Control synthesis; Distortion; Actuation voltage; Inductor; Modeling; Output voltage; Modulation; Voltage stability; Power system load; Control method; Feedforward; Inverter; High performance; Up converter; Control system; Switching function; Power electronics; Experimental study; Step down convertor; Bidirectional converter; Deadtime; System simulation; Miniaturization
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2010.2103957

This paper proposes a bidirectional buck-boost cascade inverter and presents its modeling and control methods. The proposed inverter can be seen as the cascade of a buck converter and a boost converter, both with bipolar outputs. The buck stage maintains the main inductor current and the boost stage controls the output voltage to track a given reference. With detailed analysis, the switching function model is established, which reveals that the inverter has an extra control freedom for achieving high performance. Then, the averaged model for control is given and thereby the buck-boost capability is proven. Afterward, utilizing the feedforward compensation technique, a decoupled control scheme is designed. A new modulation strategy is also proposed to minimize the dead time effect. By simulations and experiments, it is verified that the proposed system possesses the following features: 1) bidirectional operation with bipolar buck-boost output voltage; 2) reduced output distortion due to advanced modulation minimizing the dead time effect; 3) reduced size and weight with only one main energy storage component; 4) decoupled linear controller design; and 5) good steady-state and dynamic performance including wide operation range, strong robustness to load and input voltage variations, fast dynamic response, and excellent overload protection.