Cascade dual-boost/buck active-front-end converter for intelligent universal transformer

• Published in: IEEE transactions on industrial electronics (1982) Vol. 59; no. 12; pp. 4671 - 4680
• Main Authors: Liu, Chuang, Sun, Pengwei, Lai, Jih-Sheng, Ji, Yanchao, Wang, Mingyan, Chen, Chien-Liang, Cai, Guowei
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.12.2012; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Active control; Active-reactive power; Buck converters; Cascade dual-boost/buck converters; Cascades; Control systems; Converters; dc grid; intelligent universal transformer (IUT); Mathematical model; Modular; MOSFETs; multilevel systems; parallel-output converters; Power control; Power conversion; Reactive power; Steady-state; Switches; Transformers; Voltage control
• ISSN: 0278-0046; 1557-9948
• DOI: 10.1109/TIE.2011.2182014

In this paper, a new cascade active-front-end converter based on dual-boost/buck converters is proposed for an intelligent universal transformer (IUT), which allows adjusting the power factor to control both the active and reactive powers between medium and low voltage levels. Compared to the traditional cascade H-bridge converter, it has much enhanced system reliability owing to no shoot-through problems and lower switching loss with the help of using power MOSFETs. In addition, a unified control scheme is proposed for active-reactive power control and individual voltage balancing control, which is modular and easy to implement. In the end, a laboratory three-unit cascade active-front-end converter based on the half-bridge dual-boost/buck converter is constructed and tested. The experimental results verified the feasibility and effectiveness of the proposed active-front-end converter and the unified control scheme for IUT.