Flexible Transient Design-Oriented Model Predictive Control for Power Converters

• Published in: IEEE transactions on industrial electronics (1982) Vol. 71; no. 9; pp. 11377 - 11387
• Main Authors: Li, Yuan, Sahoo, Subham, Ou, Shuyu, Leng, Minrui, Vazquez, Sergio, Dragicevic, Tomislav, Blaabjerg, Frede
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.09.2024; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Closed loops; Controllers; Cost function; Custom design; Cutoff frequency; dynamic performance; Loop transfer functions; Microgrids; model predictive control (MPC); overshoot design; Power converters; Predictive control; Ruggedness; Specifications; Stability analysis; Time domain analysis; Voltage control; weighting factors
• DOI: 10.1109/TIE.2023.3331157
• ISSN: 0278-0046

Model predictive control (MPC) is one of the promising candidates for power converters with improved stability and faster response. Overshoot, a crucial transient precursor, is a custom design requirement based on the converters' applications having variant time-domain specifications that are subject to their safety and reliability. Apart from the generally accepted weight design process for improved settling time, when considering an MPC-controlled system, a theoretical framework to adjust the overshoot requirements has been overlooked so far. To bridge this gap, this article proposes a new method that integrates a flexible output voltage overshoot design method into MPC-controlled dc-dc boost converters, thereby formally ensuring that the controller always complies with the time-domain specifications under dynamic disturbances. First, this article provides the MPC controller's model by deriving the optimal duty cycle value, which is then used to derive the closed-loop transfer functions. Next, the cutoff frequency is obtained based on the transfer functions. The weighting factor ratio of the MPC, which is a tunable parameter is then adjusted to ensure an adequate system's cutoff frequency. Finally, the effectiveness and ruggedness of the proposed method are validated under experimental conditions, allowing flexibility to extend its use for different power converter applications.