Zero-Vector-Injection Based Current Sharing Control of Interleaved Full-Bridge LLC Resonant Converters

Interleaved LLC resonant converters are widely used in various fields. However, interleaved LLC converters under Pulse Frequency Modulation (PFM) will lose the regulation of individual phases, causing a load sharing problem. Existing load sharing solutions have limitations; for example, phase shedding and current sharing cannot be realized at the same time. This paper proposed a novel current sharing method for interleaved full-bridge LLC resonant converters. Based on Zero-Vector-Injection, the voltage applied to the resonant tank is controlled to compensate for the difference in gain caused by component tolerance. The modulation strategy is proposed to maintain soft switching after Zero-Vector-Injection, and the phase shedding technique is also used to improve the efficiency at a light load. The detailed theoretical analysis and implementation method are proposed and validated using simulations. Experiments are also carried out to verify the feasibility of the proposed strategy based on a 2-phase 1.8 kW prototype.

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Decoupled PI Controllers Based on Pulse-Frequency Modulation for Current Sharing in Multi-Phase LLC Resonant Converters

IEEE Access ◽

10.1109/access.2021.3053171 ◽

2021 ◽

Vol 9 ◽

pp. 15283-15294

Author(s):

Martin Moreno ◽

Javier Pereda ◽

Felix Rojas ◽

Ivan Dominguez-Lopez

Keyword(s):

Frequency Modulation ◽

Pulse Frequency ◽

Resonant Converters ◽

Pulse Frequency Modulation ◽

Current Sharing ◽

Pi Controllers ◽

Multi Phase

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A Control Actuation Concept for Self-Oscillating Resonant Converters

10.48011/asba.v2i1.1355 ◽

2020 ◽

Author(s):

William G. Rosa ◽

Lucas M. Ilha ◽

Álysson R. Seidel

Keyword(s):

Frequency Modulation ◽

Input Voltage ◽

Pulse Frequency ◽

The Self ◽

Resonant Converters ◽

Pulse Frequency Modulation ◽

Positive Type ◽

Wide Range ◽

Variable Inductor ◽

Dc Current

This paper presents a new concept of controller actuator for Self-Oscillating Resonant Converters. Simplicity, robustness, and cost-effectiveness are amongst the main features that characterize this type of converter. Described as a self-oscillating system with intrinsic positive-type feedback, also known as the self-oscillating command circuit, it performs its gate-drive with fixed frequency and duty cycle. As a result, designers often disregard this converter as an explicit solution for closed-loop applications that require extra layers of control, due to its inherent inability to operate under controlled pulse frequency modulation without modifications. Thus, in this paper, the authors propose a robust, efficient and simple way of controlling the self-oscillating resonant converter through frequency modulation. The idea consists of varying the equivalent magnetizing inductance of the self-oscillating command circuit through the addition of an extra support winding, whose inductance is subject to a current-controlled Variable Inductor. Thus, through the injection of a small controllable DC current, it is possible to modify the self-oscillating frequency of this type of converter over a wide range of input voltage and load variation, maintaining the desired output level by PFM.

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A Novel Pulse Frequency Modulation Technique for DC/DC Converter

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.860-863.2369 ◽

2013 ◽

Vol 860-863 ◽

pp. 2369-2372

Author(s):

Shu Lin Liu ◽

Ni Na Zhang

Keyword(s):

Frequency Modulation ◽

Simulation Analysis ◽

Short Circuit ◽

Short Circuit Current ◽

Pulse Frequency ◽

The Novel ◽

Pulse Frequency Modulation ◽

Modulation Technique ◽

Current Limit ◽

Light Load

In order to improve the efficiency of DC/DC converter and cut down its power loss, a novel pulse frequency modulation technique is put forward. Based on the traditional PFM, the turn-on time of the switch is reduced by current limit circuit in the case of light-load, short-circuit or other faults. Thus, the light-load loss and the short circuit current are diminished sharply. Applied the novel PFM technology, a monolithic DC-DC converter is designed, and the simulation analysis by Cadence and tape-out test results both verify the correctness and the feasibility of this design.

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