Analysis and Design of a Multi-resonant Converter with a Wide Output Voltage Range for EV Charger Applications

Wenjin Sun,Xiang Jin,Li Zhang,Haibing Hu,Yan Xing 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.4

This paper illustrates the analysis and design of a multi-resonant converter applied to an electric vehicle (EV) charger. Thanks to the notch resonant characteristic, the multi-resonant converter achieve soft switching and operate with a narrowed switching frequency range even with a wide output voltage range. These advantages make it suitable for battery charging applications. With two more resonant elements, the design of the chosen converter is more complex than the conventional LLC resonant converter. However, there is not a distinct design outline for the multi-resonant converters in existing articles. According to the analysis in this paper, the normalized notch frequency fr2n and the second series resonant frequency fr3n are more sensitive to the notch capacitor ratio q than the notch inductor ratio k. Then resonant capacitors should be well-designed before the other resonant elements. The peak gain of the converter depends mainly on the magnetizing inductor ratio Ln and the normalized load Q. And it requires a smaller Ln and Q to provide a sufficient voltage gain Mmax at (Vo_max, Po_max). However, the primary current increases with (LnQ)<SUP>-1</SUP>, and results in a low efficiency. Then a detailed design procedure for the multi-resonant converter has been provided. A 3.3kW prototype with an output voltage range of 50V to 500V dc and a peak efficiency of 97.3 % is built to verify the design and effectiveness of the converter.

Analysis and Design of a Multi-resonant Converter with a Wide Output Voltage Range for EV Charger Applications

Sun, Wenjin,Jin, Xiang,Zhang, Li,Hu, Haibing,Xing, Yan The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.4

This paper illustrates the analysis and design of a multi-resonant converter applied to an electric vehicle (EV) charger. Thanks to the notch resonant characteristic, the multi-resonant converter achieve soft switching and operate with a narrowed switching frequency range even with a wide output voltage range. These advantages make it suitable for battery charging applications. With two more resonant elements, the design of the chosen converter is more complex than the conventional LLC resonant converter. However, there is not a distinct design outline for the multi-resonant converters in existing articles. According to the analysis in this paper, the normalized notch frequency $f_{r2n}$ and the second series resonant frequency $f_{r3n}$ are more sensitive to the notch capacitor ratio q than the notch inductor ratio k. Then resonant capacitors should be well-designed before the other resonant elements. The peak gain of the converter depends mainly on the magnetizing inductor ratio $L_n$ and the normalized load Q. And it requires a smaller $L_n$ and Q to provide a sufficient voltage gain $M_{max}$ at ($V_{o\_max}$, $P_{o\_max}$). However, the primary current increases with $(L_nQ)^{-1}$, and results in a low efficiency. Then a detailed design procedure for the multi-resonant converter has been provided. A 3.3kW prototype with an output voltage range of 50V to 500V dc and a peak efficiency of 97.3 % is built to verify the design and effectiveness of the converter.

교번으로 영전압 스위칭 되는 플라이백 다중공진형 컨버터

김창선 국립7개대학공동논문집간행위원회 2005 공업기술연구 Vol.5 No.-

The multi-resonant converter can effectively minimize a parasitic oscillation effectively caused by the resonant switching characteristics. So the converter can be operated at a high frequency with high efficiency. However, the voltage stress across a resonant switch is approximately four times a input voltage. It makes the increased conduction loss. In this paper, the alternately zero voltage switched flyback multi-resonant converter is proposed. It can reduce the voltage stress to approximately three times a input voltage using two resonant switches and two series input capacitors. The operation of the proposed converter was verified through the experiment.

AT 플라이백 다중공진형 컨버터 동작모드 해석

朴貴哲(Gwi-Cheol Park),金昌宣(Chang-sun Kim) 대한전기학회 2007 전기학회논문지 Vol.56 No.7

The multi-resonant(MR) converter has a characteristics that the parasitic components existing in the converter are absorbed into the resonant circuits. The designed MR converter could be got a high efficiency and a high power density because the switching power losses are reduced effectively due to resonant switching circuit. However, the high resonant voltage stress of switching power devices leads to the conduction loss. In this paper, it is proposed the novel alternated(AT) fly back multi-resonant converter to overcome such a drawback. The suggested converter de input is divided by two series input filter capacitors. The resonant stress voltage is reduced to 2-3 times the input voltage without any complexity and it provides the various circuit schemes in lots of applications. The proposed flyback MR converter is verified through simulation and experiment.

PDP용 반파 공진형 멀티출력 하프브리지 컨버터의 다중 공진특성에 관한 연구

李在三(Jae-In Lee),孫虎仁(Ho-In Son) 대한전기학회 2006 전기학회논문지 B Vol.55 No.6

In recent years, having the advantages of being small, low in cost and high in efficiency, Half-wave resonant type, (having only one output diode), is used in ZVS Half-Bridge DC/DC converter. This paper presents the operation mode by multi-resonant factors in the Half-wave type multi-resonant converter with direct Buck chopper circuit operated in discontinuous current mode. To study the characteristics of a multi -resonant operation in steady-state, the characteristic impedances in each mode and safe operation-region(S.O.R) are reported. Computer simulation and experimental data are also given to verify the theoretical results.

A Novel Control Technique for a Multi-Output Switched-Resonant Converter

K. Sundararaman,M. Gopalakrishnan 전력전자학회 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.6

This paper proposes a novel control method for a multi-output switched-resonant converter. Output voltage can be regulated against variations in the supply voltage and load by controlling the voltage of the resonant capacitor (pulse amplitude control). Precise control is possible when pulse amplitude control is combined with pulse number control. The converter is analyzed, and design considerations are explained by using examples. Control implementation is described and load regulation and ripples are analyzed by simulation and hardware results. The topology is modified to obtain an additional negative output without any additional hardware other than a diode. The analysis of such a triple output converter with two positive outputs and one negative output is conducted and confirmed. The topology and control scheme are scalable to any number of outputs.

A Novel Control Technique for a Multi-Output Switched-Resonant Converter

Sundararaman, K.,Gopalakrishnan, M. The Korean Institute of Power Electronics 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.6

This paper proposes a novel control method for a multi-output switched-resonant converter. Output voltage can be regulated against variations in the supply voltage and load by controlling the voltage of the resonant capacitor (pulse amplitude control). Precise control is possible when pulse amplitude control is combined with pulse number control. The converter is analyzed, and design considerations are explained by using examples. Control implementation is described and load regulation and ripples are analyzed by simulation and hardware results. The topology is modified to obtain an additional negative output without any additional hardware other than a diode. The analysis of such a triple output converter with two positive outputs and one negative output is conducted and confirmed. The topology and control scheme are scalable to any number of outputs.

다출력 공진형 컨버터의 변압기 누설 인덕턴스를 고려한 특성 분석

김성재,김종수 대한전기학회 2020 전기학회논문지 Vol.69 No.3

This paper presents analysis and experimental results of cross-regulation characteristics in multi-output LLC resonant converter focus on transformer leakage inductance. The detail leakage inductance is extracted using the multi-winding transformer equivalent model, and the effects of leakage inductance on the cross-regulation characteristics under two load conditions are investigated. The analytical results are verified through an experiment results using 240W 4-output LLC resonant converter. Furthermore, the solution for reducing the cross-regulation error is discussed.

An Optimization Design of the Diode Clamped Multi-Level Converter for Coaxial Inductive Power Transfer on the Low Voltage DC Micro-grid

Worapong Pairindra,Surin Khomfoi 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.1

This proposed paper aims for the high efficiency contactless power transfer in household dc power distribution. A 300 W five-level diode clamped multi-level converter with 300 Vdc input dc link bus is employed for the power transferring task and the output voltage range is controlled at 48 Vdc. The inner and outer solenoid coils are used for inductive power transfer (IPT) transformer with the 200 ㎑ switching frequency for designed power density. Therefore, to achieve the converter efficiency above 95%, the LLC series resonant with fundamental harmonic analysis (FHA) and the calculated switching angles are used as an optimized tool for designing the system resonant tank. The validations of this approached topology are illustrated in both MATLAB/Simulink simulation and implementation.

A Parameter Selection Method for Multi-Element Resonant Converters with a Resonant Zero Point

Yifeng Wang,Liang Yang,Guodong Li,Shijie Tu 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.2

This paper proposes a parameter design method for multi-element resonant converters (MERCs) with a unique resonant zero point (RZP). This method is mainly composed of four steps. These steps include program filtration, loss comparison, 3D figure fine-tuning and priority compromise. It features easy implementation, effectiveness and universal applicability for almost all of the existing RZP-MERCs. Meanwhile, other design methods are always exclusive for a specific topology. In addition, a novel dual-CTL converter is also proposed here. It belongs to the RZP-MERC family and is designed in detail to explain the process of parameter selection. The performance of the proposed method is verified experimentally on a 500W prototype. The obtained results indicate that with the selected parameters, an extensive dc voltage gain is obtained. It also possesses over-current protection and minimal switching loss. The designed converter achieves high efficiencies among wide load ranges, and the peak efficiency reaches 96.9%.