Abstract:
Single-phase cascaded H-bridge rectifiers (CHBR) are widely studied for power electronic traction transformers (PETT). However, dynamic uncertainties, such as parameter p...Show MoreMetadata
Abstract:
Single-phase cascaded H-bridge rectifiers (CHBR) are widely studied for power electronic traction transformers (PETT). However, dynamic uncertainties, such as parameter perturbations, control delays, and external disturbances, may result in significant DC-link voltage fluctuations, degrade the quality of AC current, and even lead to system instability. Accordingly, this article proposes a μ-synthesis-based robust power control strategy to improve the control performance and robust stability of the CHBR system. First, a modified dynamic power model of the CHBR is established in the stationary reference frame, enabling direct and independent regulation of powers while eliminating phase-locked loop links. Subsequently, the μ-synthesis-based direct power control (μ-DPC) design methodology is presented, in which the structured parameter uncertainties, delay uncertainties, and external disturbance are all considered. In addition, a desired closed-loop transfer function is incorporated into the suggested power control structure to reflect the time-domain specification. With the proposed μ-DPC, the required time-domain performance, system robust stability, and robust performance can be achieved directly via a μ-synthesis framework. Finally, comparative simulation and experimental tests are conducted to verify the effectiveness of the proposed scheme.
Published in: IEEE Transactions on Transportation Electrification ( Early Access )