High-Efficiency Multilevel Flying-Capacitor DC/DC Converter for Distributed Renewable Energy Systems

Parastar, Amir; Gandomkar, Ali; Seok, Jul-Ki

doi:10.1109/tie.2015.2459057

Cited by 22 publications

(17 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Equation (10) is derived from Equation (1) by taking into account that the load current is equally shared among inductors and the voltage ratio V out /V in is proportional to d sw /2. It is important to point out that the form of Equation 10is not significantly different from equations that can be derived for an arbitrary converter with flying capacitors [9,11,13,14]. The critical capacitance in this particular converter is inherently limited by topology itself, as the ripple must not exceed the twofold voltage drop on the diodes (2v D ).…”

Section: The Origin Of the Parasitic Switching Statesmentioning

confidence: 99%

“…In the past, low switch utilization was successfully addressed in inductor-tapped solutions; with the only drawback of the increased blocking voltage [5][6][7][8]. In recent years, the voltage rating of the switch is commonly reduced by applying multi-level DC-DC converters, such as the one with a flying capacitor [9][10][11][12][13][14]. In this case, the switch utilization is increased at the price of increased control complexity.…”

Section: Introductionmentioning

confidence: 99%

“…On the other hand, in practice, a larger voltage ripple is usually allowed across flying capacitors in order to decrease the required volume in high-density designs. No serious impacts on the basic operation of the converter owed to a higher voltage ripple on flying capacitors have been reported [9][10][11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Theoretical and Experimental Investigation of the Voltage Ripple across Flying Capacitors in the Interleaved Buck Converter with Extended Duty Cycle

Zajec¹,

Nemec²

2018

Energies

View full text Add to dashboard Cite

The interleaved buck converter with an extended duty cycle is analyzed in terms of unexplored parasitic switching states that diminish the switch utilization and its safety due to high-magnitude charging and discharging currents. The analysis explains the origin of the states and their effects and demonstrates their correlation with the existing voltage ripple on flying capacitors. The article further demonstrates that the voltage ripple can no longer be arbitrarily chosen as parasitic states emerge whenever the ripple exceeds an identified critical value being equal to the twofold voltage drop on the diode. A simple design criterion for flying capacitance is proposed. For a limited set of battery-powered DC-DC converters, a solution permitting the use of smaller capacitance by adding an extra switch is proposed. The derived findings are verified using experimental and simulation results.

show abstract

Section: The Origin Of the Parasitic Switching Statesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Theoretical and Experimental Investigation of the Voltage Ripple across Flying Capacitors in the Interleaved Buck Converter with Extended Duty Cycle

Zajec¹,

Nemec²

2018

Energies

View full text Add to dashboard Cite

show abstract

“…Renewable energy systems (RESs) with various sources have attracted great interests in recent decades for their effective environmental and economical aspects [1][2][3]. Due to dependence of the photovoltaic (PV) power generation on the irradiation level of the sun, ambient temperature, and unpredictable shadows, other sources such as battery should be considered as the supplementary power source.…”

Section: Introductionmentioning

confidence: 99%

“…Non-isolated BICs can be appropriate choices for the distributed PVs since their size, cost, and efficiency are considered as significant criteria in their designing. In distributed PV systems, utilising distributed converters (often called micro converters) is proposed instead of a central one to harvest a higher energy due to different irradiation levels and unpredictable shadows [2,[12][13][14]. Hence, the multistring distributed PV architecture (a kind of architecture), as shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

Analysis and control of battery‐integrated dc/dc converters for renewable energy applications

Deihimi

Mahmoodieh

2017

IET Power Electronics

View full text Add to dashboard Cite

In this study, conventional dc/dc converters are integrated with a battery for renewable energy applications. The proposed battery-integrated dc/dc converters (BICs) can be compact size because these converters comprise just two switches and two diodes. Smaller size and desirable efficiency of the proposed BICs make it possible to use BICs in grid-connected (ongrid) distributed photovoltaic (PV) systems. The proposed BICs provide constant output power (less fluctuation) in different irradiance levels in distributed PV systems resulting in a constant output voltage at the connection point of BICs to the DC link. Besides extracting maximum power from the renewable source, output voltage is properly regulated on reference voltage in the proposed BICs. Depending on the utilisation states of the battery in grid-connected distributed PV systems, the operation of BICs is described in three scenarios. A linear quadratic regulator (LQR) control is applied to regulate output voltage and power of renewable source on references for three scenarios. Finally, the performance of the proposed BICs with LQR controller is verified by simulation (in PSCAD) and experimental results.

show abstract

Sliding mode control strategy with maximized existence region for DC–DC buck converters

Kömürcügil

2020

Int Trans Electr Energ Syst

View full text Add to dashboard Cite

Summary In this article, a sliding mode control (SMC) strategy with maximized existence region (ER) is presented for DC–DC buck converters. The ERs of the sliding mode are determined from the existence condition of the SMC. It is shown that the ER can be enlarged to its maximum size by an optimum sliding coefficient whose equation is determined analytically. Also, it is pointed out that the enlargement of the ER results in a considerable improvement in the dynamic response of the output voltage. In addition, it is shown that the optimum sliding coefficient is not sensitive to the variations in the DC input voltage and load resistance. Moreover, the capacitor current that is employed in the sliding surface function to avoid the derivative operation does not lead to any steady‐state error in the output voltage in case of an uncertainty in the capacitance value. The correctness of the proposed control approach is validated by computer simulations and experimental results. These results demonstrate that the proposed SMC strategy results in an excellent dynamic response without overshoot and undershoot in the output voltage and inductor current and guarantees a maximized ER for the sake of stronger closed‐loop stability.

show abstract

High-Efficiency Multilevel Flying-Capacitor DC/DC Converter for Distributed Renewable Energy Systems

Cited by 22 publications

References 26 publications

Theoretical and Experimental Investigation of the Voltage Ripple across Flying Capacitors in the Interleaved Buck Converter with Extended Duty Cycle

Theoretical and Experimental Investigation of the Voltage Ripple across Flying Capacitors in the Interleaved Buck Converter with Extended Duty Cycle

Analysis and control of battery‐integrated dc/dc converters for renewable energy applications

Sliding mode control strategy with maximized existence region for DC–DC buck converters

Contact Info

Product

Resources

About