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Closed-Loop Adaptive Frequency and Phase-Shift Control of Bidirectional Class-E$^2$ Converter for Energy Storage Applications

EasyChair Preprint 10423

8 pagesDate: June 20, 2023

Abstract

This paper presents discrete frequency and phase-shift control for a bidirectional class-E2 converter, enabling a wide range of output power in energy storage applications. Class-E2 converters typically operate within a narrow power range to achieve zero voltage switching (ZVS) across the switching devices and ensure high efficiency. To address this limitation, we propose an adaptive frequency control algorithm that utilizes multiple frequency steps to reduce output ripple and minimize output capacitor requirements. Our adaptive frequency control algorithm ensures high efficiency across a wide output power range by using 16 discrete switching frequency steps ranging from 800 kHz to 1.6 MHz. Duty ratios are pre-computed and stored in a lookup table to provide ZVS at each frequency. We also apply a variable phase shift between the switching devices to maintain ZVS and control the power flow direction. By directly selecting and applying the appropriate frequency from the lookup table instead of sequential searching, our proposed algorithm enables faster dynamic response with minimal undershoot and overshoot. Through simulation and implementation of closed-loop control of the bidirectional class-E2 converter prototype using an MCU, we achieved bidirectional output power level variation from 13 W to 350 W with a maximum efficiency of 93.5%.

Keyphrases: Bidirectional power flow, frequency control, resonant converters

BibTeX entry
BibTeX does not have the right entry for preprints. This is a hack for producing the correct reference:
@booklet{EasyChair:10423,
  author    = {Kamlesh Sawant and Jungwon Choi},
  title     = {Closed-Loop Adaptive Frequency and Phase-Shift Control of Bidirectional Class-E$^2$ Converter for Energy Storage Applications},
  howpublished = {EasyChair Preprint 10423},
  year      = {EasyChair, 2023}}
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