Efficiency improvement in multiphase converter by changing dynamically the number of phases

Zumel, P.; Fernnndez, C.; Castro, Ángel de; García, O.

doi:10.1109/pesc.2006.1712202

Cited by 95 publications

(41 citation statements)

References 5 publications

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“…The efficiency improvement through the phaseshedding concept has already been demonstrated in literature in [11] - [13]. This concept is illustrated in Fig.…”

Section: Benefitsmentioning

confidence: 91%

“…In a standard operation scheme, the modules process the same amount of power and therefore p 1 = p 2 = p 3 . An operation method based on the activation and deactivation of modules in order to improve the efficiency in light load was proposed in [11]. Currently, this concept is known as phaseshedding technique and it is commonly used in multiphase systems.…”

Section: Power Routingmentioning

confidence: 99%

See 1 more Smart Citation

Smart Transformer reliability and efficiency through modularity

Andresen

Costa

Buticchi

et al. 2016

2016 IEEE 8th International Power Electronics and Motion Control Conference (IPEMC-ECCE Asia)

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“…The efficiency improvement through the phaseshedding concept has already been demonstrated in literature in [11] - [13]. This concept is illustrated in Fig.…”

Section: Benefitsmentioning

confidence: 91%

Section: Power Routingmentioning

confidence: 99%

Smart Transformer reliability and efficiency through modularity

Andresen

Costa

Buticchi

et al. 2016

2016 IEEE 8th International Power Electronics and Motion Control Conference (IPEMC-ECCE Asia)

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“…A larger RMS current leads to higher conduction losses in each MOSFET, in ESR of output capacitance, and in DCR of inductor [10]. Such a power stage has MOSFETs designed with Dynamically changing the number of phases is explored further in [12], focusing on design issues with practical implementation. Design issues include uneven current sharing upon connecting phases and decreased load transient performance from disconnecting and connecting phases.…”

Section: Shortcomingsmentioning

confidence: 99%

A two-phase buck converter with optimum phase selection for low power applications

Yeago¹,

Hyun²,

Ha³

et al. 2015

2015 IEEE Energy Conversion Congress and Exposition (ECCE)

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Power consumption of smart cameras varies significantly between sleep mode and active mode, and a smart camera operates in sleep mode for 80 -90% of time for typical use. To prolong the battery life of smart cameras, it is essential to increase the power converter efficiency for light load, while being able to manage heavy load. The power stage of traditional buck converter is optimized for maximum load, at the cost of light-load efficiency. Wei proposed a multiphase buck converter incorporating the baby-buck concept and optimum number of phases (ONP) control. This thesis research investigated Wei's multiphase buck converter to improve the light-load efficiency for smart cameras as the target application.The proposed two-phase buck converter aims to provide power for microprocessors of smart cameras. The input voltage of the converter is 5 V DC, and the output voltage is 1.2 V DC with power dissipation range of 25 mA (30 mW) for light load and 833 mA (1 W) for heavy load. Three methods are considered to improve light-load efficiency: adopting baby-buck concept, adapting ONP control for low-power range, and implementing a pulse frequency modulation (PFM) control scheme with discontinuous conduction mode (DCM) to lower switching frequency. The first method is to adopt the baby-buck concept through power stage design of each phase to optimize efficiency for a specific load range. The baby-buck phase is optimized for light load and the heavyload phase is designed to handle the processors maximum power consumption. The second method performs phase selection from sensed load current information. Rather than have all phases active for heavy-load as in ONP control, optimum phase selection (OPS) control is introduced to adaptively select between phases based on load current. Due to low-power constraints, OPS is more efficient for the medium to heavy-load range. The transition between phases due to load iii change is also investigated. The third and final method implements PFM control with DCM to lower switching frequency and reduce switching and driving losses under light load. PFM is accomplished with a constant on-time (COT) valley current mode controller, which uses the inductor current information and output voltage to generate switching signals for both the top and bottom switches. The baby-buck phase enters DCM to lower switching frequency under very light load, while the heavy-load phase remains in continuous conduction mode (CCM) throughout its load range.The proposed two-phase buck converter is designed and prototyped using discrete components. Efficiency of the two-phase converter and a power loss breakdown for each block in the control scheme were measured. The efficiency ranges from 64% to 81% for light load ranging of 30 mW to 200 mW, and the efficiency ranges from 81% to 88% for heavy load ranging from 200 mW to 1 W. The majority loss is due to controllers, which are responsible for 37 % (8.6 mW) for light load of 60 mW and for 10.9 % (9 mW) for heavy load of 600 mW. The gate driver loss is consider...

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“…Zumel et al employ an interleaved buck converter and dynamically varies the number of active phases as a function of load demand, aiming to achieve loss reduction in light load operation [7]. Abu-Qahouq et al investigate the effects that several power distributions among the phases of an interleaved buck converter have on the efficiency of the converter.…”

Section: Introductionmentioning

confidence: 99%

A new method to improve the total efficiency of parallel converters

Dupont

Zaragoza

Rech

et al. 2013

2013 Brazilian Power Electronics Conference

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Abstract-This paper proposes a new methodology for efficiency optimization in systems composed by parallel converters. The proposed methodology takes into account the individual efficiency curves and determines the optimum operating point for each converter such that the maximum efficiency of the arrangement is achieved for the entire load range. Due to the nonlinearity of the problem and the complexity of the solution hyperplane, the optimization process is divided into stages of global optimization, local optimization and ambiguity resolution. This latter verifies the existence of multiple global minima and selects the most appropriate in function of previous power distributions. Case studies demonstrates the validity of the proposed methodology for different systems configurations.

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Efficiency improvement in multiphase converter by changing dynamically the number of phases

Cited by 95 publications

References 5 publications

Smart Transformer reliability and efficiency through modularity

Smart Transformer reliability and efficiency through modularity

A two-phase buck converter with optimum phase selection for low power applications

A new method to improve the total efficiency of parallel converters

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