A New Interleaved Three-Phase Single-Stage PFC AC-DC Converter with Flying Capacitor

 

ABSTRACT:

A new interleaved three-phase PFC AC-DC single-stage multilevel is proposed in this paper. The proposed converter can operate with reduced input current ripple and peak switch currents due to its interleaved structure, a continuous output inductor current due to its three-level structure, and improved light-load efficiency as some of its switches can be turned on softly. In the paper, the operation of the converter is explained, the steady-state characteristics of the new converter are determined and its design is discussed. The feasibility of the new converter is confirmed with experimental results obtained from a prototype converter and its efficiency is compared to that of another multilevel converter of similar type.

 KEYWORDS:

  1. AC-DC power factor correction
  2. Single-stage converters
  3. Three-Phase Systems
  4. Three level converters
  5. Phase shifted modulation.

 SOFTWARE: MATLAB/SIMULINK

 CIRCUIT DIAGRAM:
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Fig. 1. An interleaved three-phase three-level converter.

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Fig. 2. Proposed single-stage three-level ac-dc converter.

 EXPECTED SIMULATION RESULTS:

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 (a) Input current and voltage (V: 100 V/div, I: 4 A/div)

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(b) Primary voltage of the main transformer (V:100V/div.,t: 4 µs/div.)

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(c) Vds and Id current of S4 (V: 100V/div., I:5A/div, t:10 µs/div.s)

Fig. 3. Typical converter waveforms.

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Fig. 4. Efficiency of PWM and PSM three-level single-stage ac-dc converters

CONCLUSION:

A new interleaved three-phase, three-level, single-stage power-factor-corrected AC-DC converter using standard phase-shift PWM was presented in this paper. In this paper, the operation of the converter was explained and its feasibility was confirmed with experimental results obtained from a prototype converter. The efficiency of the new converter was compared to that of another converter of the same type. It was shown that the proposed converter has a better efficiency, especially under light-load conditions, and it was explained that this is because energy from the output inductor can always be used to ensure that the very top and the very bottom switches can be turned ON with ZVS, due to a discharge path that is introduced by its flying capacitor.

REFERENCES:

[1] “Limits for Harmonic Current Emission (Equipment Input Current>16A per Phase),” IEC1000-3-2 International Standard, 1995.

[2] J.M. Kwon, W.Y. Choi, B.H. Kwon, “Single-stage quasi-resonant flyback converter for a cost-effective PDP sustain power module,” IEEE Trans. on Industrial. Elec., vol. 58, no. 6, pp 2372-2377, 2011.

[3] H.S. Ribeiro and B.V. Borges, “New optimized full-bridge single-stage ac/dc converters,” IEEE Trans. on Industrial. Elec., vol. 58, no. 6, pp. 2397-2409, 2011.

[4] N. Golbon, and G. Moschopoulos, “A low-power ac-dc single-stage converter with reduced dc bus voltage variation”, IEEE Trans. on Power Electron., vol. 27, no.8, pp. 3714–3724, Jan. 2012.

[5] H. M. Suraywanshi, M.R. Ramteke. K. L. Thakre, and V. B. Borghate, “Unity-power-factor operation of three phase ac-dc soft switched converter based on boost active clamp topology in modular approach,” IEEE Trans. on Power Elec., vol. 23, no. 1., pp. 229-236, Jan. 2008.