Model-Free Control of Single-Phase Boost AC/DC Converters
Hengguo Zhang, Hongmei Li, Jingkui Mao, Chen Pan, Zhiyuan Luan
Abstract
Conventionally, the benchmark proportional-integral control method is implemented to realize power factor correction and output voltage regulation of single-phase ac/dc converters. However, the performance is deteriorated due to the influence of uncertainties and disturbances, e.g., periodic input voltage and load variation. Concerning this problem, this article proposes a model-free control (MFC) strategy of single-phase ac/dc converters. The MFC principle is revisited and a frequency response analysis is presented for the algebraic estimators of uncertainties and disturbances. Consequently, the closed-loop performance of MFC systems is allowed to be analyzed in frequency domain via classical linear control theory. Based on the theoretical results, the model-free current and voltage control systems are synthesized in detail to achieve control objectives of the converter. Simulation results demonstrate the performance of MFC systems in reference tracking and disturbance rejection. The feasibility and validity of the presented MFC strategy for single-phase boost ac/dc converters is also confirmed experimentally as compared to the benchmark scheme.