Current Sharing Analysis for Novel Paralleled CLLLC Converters

Wang, Xinrui; Liu, Bin; Jiang, Liangxing; Zhan, Zhiwang

doi:10.1109/access.2021.3119937

Cited by 7 publications

(7 citation statements)

References 21 publications

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“…The applicability of the proposed CRT topology is the same as that of traditional multiphase LLC converters. For example, the CRT topology can be applied to the auxiliary power supply of electric vehicles [22, 23], the CPU load power supply of the data centre [24, 25], and the charging and discharging of energy storage batteries in the DC micro‐grid system [26].…”

Section: Proposed Crt Current Sharing Methodsmentioning

confidence: 99%

Depth comparison of common inductor and common capacitor passive current sharing methods for multiphase LLC converter

Sun,

Wu,

Wang

et al. 2023

IET Power Electronics

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Common inductor (CIM) and common capacitor (CCM) passive current‐sharing methods have the advantages of simple implementation and low cost. However, there is still a lack of detailed comparative research on the two methods, which makes researchers confused when choosing the two methods. To provide clear scheme guidance, this paper provides a detailed comparison of the performance of the two methods. Firstly, this paper reveals the difference between the current waveforms of the two methods, that is, the current waveform of the CIM method is distorted, while the CCM method is non‐distorted. Then, the mechanism of the above phenomenon is analysed in depth. Secondly, for comparing the current sharing performance of the two methods, the first harmonic approximation (FHA) equivalent circuit model considering parasitic parameters is established to obtain the system's current sharing error model, and the parameter sensitivity analysis is provided. Finally, the relationship between the current waveform, current sharing error, and load ripple of the two methods is discussed. Then, based on the two methods, a more attractive common resonate tanks (CRT) current‐sharing method is proposed. The correctness of the view in this paper has been verified by extensive simulations and experiment results.

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Section: Proposed Crt Current Sharing Methodsmentioning

confidence: 99%

Depth comparison of common inductor and common capacitor passive current sharing methods for multiphase LLC converter

Sun,

Wu,

Wang

et al. 2023

IET Power Electronics

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“…In order to maintain structural symmetry, reference [16] shows a CLLLC resonant converter that introduces a set of resonant networks on the secondary-side of the LLC resonant converter, so the equivalent circuits are the same in forward and reverse operation. Reference [17] shows the gain characteristics, impedance characteristics, errors and floating of resonance parameters of the CLLLC resonant converter in detail, under suitable operating conditions, the CLLLC resonant converter has the good characteristics of the LLC resonant converter when the circuit parameters are symmetrical, and it is a bidirectional DC/DC converter that is more studied and more recognized by scholars at home and abroad. Reference [18] shows a family of two-phase interleaved LLC resonant converter with hybrid rectifier.…”

Section: Figure 2 Structure Of On-board Charging Systemmentioning

confidence: 99%

“…[10] Dual The efficiency of the system needs to be improved. [17] Paralleled CLLLC Converters 2 100 200 16/16 96.6% It has large system capacity, power density and better current sharing characteristics.…”

Section: Bidirectional Totem Pole Convertermentioning

confidence: 99%

“…In order to analyze the characteristics of the rear-stage converter, the equivalent circuit model is established by the fundamental wave analysis method, which only considers the fundamental components and ignores the influence of higher harmonics on the power conversion [26]. Reference [27] shows the equivalent circuit model established by fundamental wave analysis, and analyzes the voltage gain and impedance characteristics in detail. Taking phase A as an example, the equivalent model when it operates in forward charging mode is shown in Fig.…”

Section: B Equivalent Circuit Model Of Resonant Convertermentioning

confidence: 99%

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Research on Bidirectional On-Board Charging System Based on Three-Phase Wye-Wye Connected CLLLC Resonant Converter

Zhou,

Huang,

Zheng

2023

IEEE Access

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The traditional on-board charging system can only realize the one-way transmission of electric energy from the grid to the power battery. To address this issue, this paper proposes a bidirectional on-board charging system based on a three-phase wye-wye connected CLLLC resonant converter. It adopts a two-stage structure, the front-stage is a bidirectional totem pole converter and the rear-stage is a threephase wye-wye connected CLLLC resonant converter. Based on the grid characteristics, the working principle of the front-stage converter is analyzed, the equivalent circuit model of the rear-stage converter is derived using fundamental wave analysis, and the voltage gain, impedance characteristics and zero voltage turn-on conditions are analyzed. The parameters of input inductor, DC bus capacitance and resonant network are calculated according to the design specifications of the bidirectional on-board charging system. The control strategy of bidirectional vehicle charging system is studied. The input current and input voltage are kept in the same phase by establishing the small signal circuit model of the front-stage bidirectional totem pole converter. The rear-stage three-phase wye-wye connected CLLLC resonant converter adopts pulse frequency modulation to realize constant voltage and constant current output of the charging system. Simulation software was used to simulate the bidirectional on-board charging system, and a 3.3 kW prototype was trial-produced according to the main circuit parameters. Simulation and experimental results verify the correctness of the design of the bidirectional on-board charging system.INDEX TERMS Bidirectional on-board charging system, resonant converter, three-phase wye-wye connected, totem pole converter.

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“…Several research studies have been carried out to improve the performance of CLLLC resonant BDCs for various applications because of the CLLLC resonant converter's current popularity and broad application prospects. For instance, Wang et al [17] developed a novel paralleled CLLLC converter technique that distributes system load evenly among the parallel CLLLC units. As a consequence, the system power handling capability and power density can be enhanced.…”

Section: Introductionmentioning

confidence: 99%

An Improved Topology of Isolated Bidirectional Resonant DC-DC Converter Based on Wide Bandgap Transistors for Electric Vehicle Onboard Chargers

Shahed

Rashid

2023

International Transactions on Electrical Energy Systems

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This article proposes an improved topology for an isolated bidirectional resonant DC-DC converter for electric vehicle (EV) onboard chargers. As opposed to the conventional capacitor-inductor-inductor-inductor-capacitor (CLLLC) resonant converter, the proposed converter’s resonant circuit is composed of a capacitor-inductor-inductor-inductor (CLLL) structure, whose inductances, except the capacitor, can be fully integrated with the leakage and mutual inductances of the high-frequency transformer (HF). Therefore, this offers a smaller size, lower costs, minimal power loss, and eventually higher efficiency. Again, the proposed converter design is based on wide bandgap (WBG) transistor switches that operate at MHz-level switching frequency to achieve high power density, high efficiency, and high compactness. A discrete-time proportional integral derivative (PID) controller has been designed using the phase-shifted pulse width modulation (PSPWM) technique to assure closed-loop control of the proposed CLLL converter. The PID controller parameters have been optimized using both the genetic algorithm (GA) and particle swarm optimization (PSO) algorithm and a comparative analysis has been presented between the two algorithms. To achieve fast switching with very little switching loss, the converter is simulated with several wide bandgap (WBG) switching devices. A performance comparison with conventional Si-based switching devices is also provided. A precise power loss model of the semiconductor switches has been devised from the manufacturer’s datasheet to achieve a perfect thermal design for the converter. A 5 kW CLLL converter with an input range of 400–460 V direct current (DC) and an output range of 530–610 V DC, and a switching frequency of 1 MHz has been designed and investigated under various loading scenarios. Gallium nitride (GaN) switching device-based designs achieved the highest levels of efficiency among the switching devices. The efficiency of this device is 97.40 percent in charging mode and 96.67 percent in discharging mode.

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Current Sharing Analysis for Novel Paralleled CLLLC Converters

Cited by 7 publications

References 21 publications

Depth comparison of common inductor and common capacitor passive current sharing methods for multiphase LLC converter

Depth comparison of common inductor and common capacitor passive current sharing methods for multiphase LLC converter

Research on Bidirectional On-Board Charging System Based on Three-Phase Wye-Wye Connected CLLLC Resonant Converter

An Improved Topology of Isolated Bidirectional Resonant DC-DC Converter Based on Wide Bandgap Transistors for Electric Vehicle Onboard Chargers

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