TY - JOUR
T1 - Extended harmonics based phase tracking for synchronous rectification in CLLC converters
AU - Sankar, Arun
AU - Mallik, Ayan
AU - Khaligh, Alireza
N1 - Funding Information:
Manuscript received April 4, 2018; revised August 7, 2018 and August 30, 2018; accepted September 19, 2018. Date of publication October 19, 2018; date of current version March 29, 2019. This work was supported in part by the National Science Foundation under Grant 1507546 and Grant 1602012 (Corresponding author: Alireza Khaligh.) The authors are with the Electrical and Computer Engineering Department, University of Maryland at College Park, College Park, MD 20742 USA (e-mail:, arunsu@terpmail.umd.edu; mallik@umd.edu; khaligh@ ece.umd.edu).
Publisher Copyright:
© 2018 IEEE.
PY - 2019/8
Y1 - 2019/8
N2 - Synchronous rectification (SR) is one of the well-known methods to reduce the conduction losses by replacing the power diodes. The control of SR requires the phase information of the device current. In this paper, a novel extended harmonics approximation modeling approach is introduced for CLLC resonant converters to estimate the phase of its secondary side current accurately. Conventionally, the first harmonic approximation (FHA) is used to model any resonant converter; however, FHA works more accurately near the resonant frequency operation. But in case of a set of unmatched LC tank parameters in the primary and secondary side of a CLLC converter, there is no uniquely defined resonant frequency, which reduces the accuracy of the FHA model. Unlike FHA-based approach, our proposed modeling considers the effects of other odd order harmonics present in the square wave voltage waveform towards determining the zero-crossing instant or phase information of the resonant currents. The proposed concept is verified through experimental results obtained at 3.3-kW load condition, and the converter efficiency is improved by 1.8% with the proposed phase tracking technique, compared to FHA modeling approach.
AB - Synchronous rectification (SR) is one of the well-known methods to reduce the conduction losses by replacing the power diodes. The control of SR requires the phase information of the device current. In this paper, a novel extended harmonics approximation modeling approach is introduced for CLLC resonant converters to estimate the phase of its secondary side current accurately. Conventionally, the first harmonic approximation (FHA) is used to model any resonant converter; however, FHA works more accurately near the resonant frequency operation. But in case of a set of unmatched LC tank parameters in the primary and secondary side of a CLLC converter, there is no uniquely defined resonant frequency, which reduces the accuracy of the FHA model. Unlike FHA-based approach, our proposed modeling considers the effects of other odd order harmonics present in the square wave voltage waveform towards determining the zero-crossing instant or phase information of the resonant currents. The proposed concept is verified through experimental results obtained at 3.3-kW load condition, and the converter efficiency is improved by 1.8% with the proposed phase tracking technique, compared to FHA modeling approach.
KW - CLLC
KW - extended harmonic modeling
KW - first harmonic approximation (FHA)
KW - resonant converter
KW - synchronous rectification (SR)
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U2 - 10.1109/TIE.2018.2874348
DO - 10.1109/TIE.2018.2874348
M3 - Article
AN - SCOPUS:85055146239
SN - 0278-0046
VL - 66
SP - 6592
EP - 6603
JO - IEEE Transactions on Industrial Electronics
JF - IEEE Transactions on Industrial Electronics
IS - 8
M1 - 8500739
ER -