Download switched inductor/switched-capacitor combined active

MULTICELL SWITCHED-INDUCTOR/SWITCHED CAPACITOR COMBINED
ACTIVE-NETWORK CONVERTERS
ABSTRACT:
High step-up voltage gain dc/dc converters are widely used in renewable energy power
generation, uninterruptible power system, etc. In order to avoid the influence of leakage inductor
in coupled inductors based converters, switched-inductor boost converter (SL-boost), switchedcapacitor boost converter (SC-boost) and active-network converter (ANC) have been developed.
With the transition in series and parallel connection of the inductors and capacitors, high step-up
voltage conversion ratio can be achieved. This paper discusses the characteristics of the switched
inductor and switched-capacitor cell; makes some comparisons between the ANC and boost
converter. Based on the aforementioned analysis, this paper proposed the multicell switchedinductor/ switched capacitor combined active network converters (MSL/SC-ANC). The proposed
converters combine the advantages of SL/SC unit and active-network structure. Compared with
previous high step up converters, the novel converter provides a higher voltage conversion ratio
with a lower voltage/current stress on the power devices, moreover, the structure of proposed
SL/SC-ANC is very flexible, which means the quantity of SL and SC cells can be adjusted
according to required voltage gain. A 20 times gain prototype is designed as an example to show
the design procedure. Theoretical analysis and experimental results are presented to demonstrate
the feature of the proposed converter
INTRODUCTION:
In order to achieve a high step-up voltage gain with high efficiency, many researches have been
concentrated on transformer less high step-up voltage gain dc/dc converters. By increasing the
turns ratio of the coupled inductors which is similar to that in isolated converters, high-voltage
conversion ratio is obtained.
Unfortunately, the leakage inductor may have a great influence on the voltage stress of the
switches, which induces additional passive and active snubbers to absorb the voltage spike. To
avoid the influence of the leakage inductor, the noncoupled inductor type transformerless dc/dc
converters have been discussed.
With the transition of the inductors and capacitors in series and parallel connection, SL-boost
converter, SC-boost and ANC have been proposed. The SL and SC cell is utilized in voltagetype and current-type Z-source inverters, respectively. However, the voltage gain is still not high
enough with either SL or SC cell
In order to achieve a high step-up voltage gain with high efficiency, many researches have been
concentrated on transformer less high step-up voltage gain dc/dc converters. By increasing the
turns ratio of the coupled inductors which is similar to that in isolated converters, high-voltage
conversion ratio is obtained.
Unfortunately, the leakage inductor may have a great influence on the voltage stress of the
switches, which induces additional passive and active snubbers to absorb the voltage spike. To
avoid the influence of the leakage inductor, the noncoupled inductor type transformer less dc/dc
converters have been discussed.
With the transition of the inductors and capacitors in series and parallel connection, SL-boost
converter, SC-boost, and ANC have been proposed. The SL and SC cell is utilized in voltagetype and current-type Z-source inverters, respectively . However, the voltage gain is still not high
enough with either SL or SC cell.
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:
This paper discusses the characteristics of the SL and SC cell, then the comparisons
between the ANC and boost converter have been given. Based on the SL-cell, SC-cell, and active
network structure, this paper proposed a multicell switched-inductor/switched-capacitor
combined active network converter (SL/SC-ANC) structure. The proposed structure provides a
high step-up voltage gain with low voltage and current stress on the power devices; in addition,
we can adjust the topology with flexible structure to meet different voltage gain and stress
requirements. This paper discusses the operational analysis including the voltage gain, the
voltage/current stress of the power devices and the inductor current value.
ADVANTAGES:

The proposed MSL/SC-ANC can achieve a high gain with a small duty cycle which is
difficult for traditional Boost converter.

The proposed MSL/SC-ANC combines the advantages of SC cell that reduce voltage
stress of output diode SL cell and active-network which can bring down voltage stress of
switches.

The inductors in the SL-cell can be integrated into one magnetic core, which helps to
reduce the size of magnetic components.

The proposed MSL/SC-ANC is flexible, which can adjust the quantity of SL cells and SC
cells according to required gain.
BLOCK DIAGRAM:
SWITCHED INDUCTOR/SWITCHEDCAPACITOR COMBINED ACTIVENETWORK
INPUT DC
SUPPLY
12V
DC
5V DC
OPTO COUPLER CIRCUIT
PIC CONTROLLER WITH
BUFFER
TOOLS AND SOFTWARE USED:

MPLAB – microcontroller programming.

ORCAD – circuit layout.

MATLAB/Simulink – Simulation
APPLICATIONS:

High step-up voltage conversion.
 Photovoltaic and fuel cell stack.
LOAD
CONCLUSION:
Based on the SL cell and SC cell, this paper proposed the MSL/SC combined activenetwork dc/dc converters. The characteristics of the converters are shown as following:
1) the proposed MSL/SC-ANC can achieve a high gain with a small duty cycle which is
difficult for traditional Boost converter;
2) the proposed MSL/SC-ANC combines the advantages of SC cell that reduce voltage
stress of output diode SL cell and active-network which can bring down voltage stress of
switches;
3) the inductors in the SL-cell can be integrated into one magnetic core, which helps to
reduced the size of magnetic components;
4) the proposed MSL/SC-ANC is flexible, which can adjust the quantity of SL cells and
SC cells according to required gain. Considering all these advantages, the proposed ∗ ∗
MSL/SCANCis suitable for high step-up voltage conversion applications and the experimental
results verify the correctness
REFERENCES:
[1] W. Li, Y. Zhao, J. Wu, and X. He, “Interleaved high step-up converter with winding-crosscoupled inductors and voltage multiplier cells,” IEEE Trans. Ind. Electron., vol. 27, no. 1, pp.
133–143, Jan. 2012.
[2] C. S. Chin, P. Neelakantan, and H. P. Yoong, “Maximum power point tracking for PV array
under partially shaded conditions,” in Proc. IEEE CICSyN, 2011, pp. 72–77.
[3] J. C. Rosas-Caro, J. M. Ramirez, F. Z. Peng, and A. Valderrabano, “A dc–dc multilevel boost
converter,” IET-Elect. Power Appl., vol. 59, no. 1, pp. 129–137, Jan. 2009.
[4] W. Li, J. Liu, J. Wu, and X. He, “Design and analysis of isolated ZVT boost converters for
high-efficiency and high-step-up applications,” IEEE Trans. Power Electron., vol. 22, no. 6, pp.
2363–2374, Nov. 2007.