Maximum Efficiency Tracking and ZVS Realization for Wide Output Voltage Range Employing Segmented TPS Modulation Scheme
Mingyang Li, Junjun Deng, Deliang Chen, Wenbo Wang, Zhenpo Wang
Abstract
The efficiency of wireless power transfer (WPT) systems is highly dependent on the load and dc voltage gain, which may change in a wide range in electric vehicle (EV) charging applications. Besides, existing control triple-phase-shift (TPS) strategies aimed at power regulation, zero-voltage switching (ZVS) realization and maximum efficiency point tracking (MEPT) have limitations when applied to the wide output voltage application. To fill this gap, a segmented TPS modulation scheme is proposed. Considering wide-range ZVS, three different working modes are derived to achieve MEPT over the wide output voltage range. The proposed modulation scheme employs closed-loop control by integrating different working modes. In addition, the efficiency-oriented seamless transition method among different working modes is described, which can avoid the transient oscillation at the boundary of the mode transition. The proposed modulation scheme's on-state loss and switching loss are compared to the traditional TPS modulation scheme. Finally, a 1.5 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> W prototype has been built to verify effectiveness of the proposed modulation scheme within the wide voltage range, and the measured efficiency can be increased by up to 0.82% in the deep buck mode and 2.20% in the deep boost mode.