Download high step-up interleaved forward-flyback boost

HIGH STEP-UP INTERLEAVED FORWARD-FLYBACK BOOST
CONVERTER WITH THREE-WINDING COUPLED INDUCTORS
ABSTRACT:
A novel high step-up interleaved converter for high-power high-voltage
applications is proposed in this paper. Through three-winding coupled inductors, a
high step-up conversion with high efficiency is obtained. The proposed converter
not only reduces the current stress, but also constrains the input current ripple,
which decreases the conduction losses and lengthens the life time of input source.
In addition, due to the lossless passive clamp performance, leakage energy is
recycled to the output terminal. Hence, large voltage spikes across the main
switches are alleviated and the efficiency is improved. Even, the low-voltage
stresses on semiconductor components are substantially lower than the output
voltage. Finally, the prototype circuit with input voltage 48 V, output voltage 380
V, and output power 2 kWis operated to verify its performance. The highest
efficiency is 96.5%, and the full-load efficiency is 92.6%.
INTRODUCTION:
A novel high step-up interleaved converter for high power high-voltage
applications is proposed in this paper. Through three-winding coupled inductors, a
high step-up conversion with high efficiency is obtained. The proposed converter
not only reduces the current stress, but also constrains the input current ripple,
which decreases the conduction losses and lengthens the life time of input source.
In addition, due to the lossless passive clamp performance, leakage energy is
recycled to the output terminal. Hence, large voltage spikes across the main
switches are alleviated and the efficiency is improved. Even, the low-voltage
stresses on semiconductor components are substantially lower than the output
voltage
The proposed boost/forward/flyback converter not only utilizes the switched
capacitors, but also integrates three-winding characteristics well into coupled
inductors, which achieves more
flexible step-up regulation and voltage stress adjustment. Thus, the proposed
converter is suitable as an excellent candidate for high step-up conversion with
high power and high efficiency.
The three-winding coupled inductors can be designed to extend step-up gain and to
adjust voltage stresses. The advantages of the proposed converter are as follows: 1)
the characteristics of low-input current ripple and low conduction losses, increase
life-time of renewable energy sources and make it suitable for high-power
applications; 2) the high step-up gain that renewable energy systems require is
easily obtained; 3) leakage energy is recycled to the output terminal, hence, large
voltage spikes across the main switches are alleviated and the efficiency is
improved; 4) the low voltage stresses on semiconductor components are
substantially lower than the output voltage.
EXISTING SYSTEM:
Conventional step-up converters, such as the boost converter and flyback
converter, cannot achieve a high step-up conversion with high efficiency because
of the resistances of elements or leakage inductance; also, the voltage stresses are
large. A boost converter (step-up converter) is a DC-to-DC power converter with
an output voltage greater than its input voltage. It is a class of switched-mode
power supply (SMPS) containing at least two semiconductors (a diode and a
transistor) and at least one energy storage element, a capacitor, inductor, or the two
in combination. Filters made of capacitors (sometimes in combination with
inductors) are normally added to the output of the converter to reduce output
voltage ripple.
PROPOSED SYSTEM:
The proposed boost/forward/flyback converter not only utilizes the switched
capacitors, but also integrates three-winding characteristics well into coupled
inductors, which achieves more flexible step-up regulation and voltage stress
adjustment. Thus, the proposed converter is suitable as an excellent candidate for
high step-up conversion with high power and high efficiency. The three-winding
coupled inductors can be designed to extend step-up gain and to adjust voltage
stresses
ADVANTAGES:
 The characteristics of low-input current ripple and low conduction losses,
increase life-time of renewable energy sources and make it suitable for highpower applications.
 The high step-up gain that renewable energy systems require is easily
obtained.
 Leakage energy is recycled to the output terminal, hence, large voltage
spikes across the main switches are alleviated and the efficiency is
improved.
 The low voltage stresses on semiconductor components are substantially
lower than the output voltage.
BLOCK DIAGRAM:
TOOLS AND SOFTWARE USED:
 MPLAB – microcontroller programming.
 ORCAD – circuit layout.
 MATLAB/Simulink – Simulation
APPLICATIONS:
 Fuel cells.
 Photovoltaic cells.
CONCLUSION:
A 2-kW prototype of the proposed high step-up converter is tested. The
electrical specifications is shown in Table I. The design consideration of the
proposed converter includes components selection and coupled inductors design,
which are based on the analysis presented in the previous chapter. In the proposed
converter, the values of the primary leakage inductors of the coupled inductors are
set as close as possible for current sharing performance. Due to the performances
of high step-up gain, the turns ratios can be set as 1 for the prototype circuit to
reduce cost, volume, and conduction loss of windings. Thus, the copper resistances
which affect efficiency much can be decreased.
REFERENCES:
[1] J. T. Bialasiewicz, “Renewable energy systems with photovoltaic power
generators: Operation and modeling,” IEEE Trans. Ind. Electron., vol. 55, no. 7,
pp. 2752–2758, Jul. 2008.
[2] T.Kefalas andA.Kladas, “Analysis of transformersworking under heavily
saturated conditions in grid-connected renewable energy systems,” IEEE Trans.
Ind. Electron., vol. 59, no. 5, pp. 2342–2350, May. 2012.
[3] Y. Xiong, X. Cheng, Z. J. Shen, C. Mi, H.Wu, and V. K. Garg, “Prognostic and
warning system for power-electronic modules in electric, hybrid electric, and fuelcell vehicles,” IEEE Trans. Ind. Electron., vol. 55, no. 6, pp. 2268–2276, Jun.
2008.
[4] A. K. Rathore, A. K. S. Bhat, and R. Oruganti, “Analysis, design and
experimental results of wide range ZVS active-clamped L-L type currentfed dc/dc
converter for fuel cells to utility interface,” IEEE Trans. Ind. Electron., vol. 59, no.
1, pp. 473–485, Jan. 2012