International Conference on Engineering and Technology - 2013
88
Neuro-Fuzzy Control Based Negative Output KY
Boost Converter
A. Vignesh Raja and S. Krishna Kumar
Abstract--- A converter named negative output KY boost
converter is presented herein which combines along with the
neuro fuzzy controller to produce the negative output source
and to reduce its output voltage ripple around 3mv.In the
following the theoretical analysis is given in detail. Both the
simulation and experimental results are found out and given in
detail for the KY converter topology
Index Terms--- Direct-Current–Direct-Current (DC–DC)
Converter, KY Boost Converter, Neuro Fuzzy
I.
INT RODUCTION
I
N many applications, such as analog signal applications,
communicat ions applications, the negative electricity source
is indispensable for the audio amp lifier, the signal generator or
the data transmission interface, etc. And hence, if such a
source comes fro m the main, then there is an additional
winding in design of the transformer. However, if such a
source is provided for the battery in the car or the portable
device, then a DC-DC converter, based on the charge pump
[1], is taken, but is suitable for low-power applicat ions in
order to limit the undesired surge current to some extent.
In consequence, Cuk and Luo converters [2-5] are
presented to overcome the above problem. However, for
voltage boosting to be considered, the Cuk converter needs
two inductors and one additional energy-transferring
capacitor, and the Luo converter possesses more components
than the Cuk converter does. In a novel converter named
negative KY boost converter they reduced the output voltage
ripple around 60mv by using an FPGA-PID controller.
Based on the previous statements a novel negative KY
converter using neuro fuzzy method is presented herein. By
using the neuro fuzzy model here I am going to reduce the
output voltage ripple around 3mv. In the following, the basic
operating principles of the proposed converter are described in
detail, together with some simu lated results to demonstrate its
effectiveness.
Fig.1.Circuit diagram of the proposed KY-boost converter
based on neuro fuzzy controller. Its components are described
in the text.
The structure proposed circuit and its operation principles
are described in Section II. The design considerations are
given in Sect ion III. The experimental results are given in
Section IV, and a conclusion is given in Sect ion V.
II.
CIRCUIT OPERATION
A. Circuit Description
As shown in Fig.1, the following is the proposed
converter, named as KY converter, which consists of two
MOSFET switches S1 and S2 along with anti-d iodes DI and
D2 respectively, one diode D, one energy-transferring
capacitor Cb which is large enough to keep the voltage across
itself constant at the value of the input voltage, one output
inductor L, and one output capacitor C.The voltage
divider,co mparator and the neuro fuzzy-based counteredbased control without any analogue-to-digital converter is
used herein to do the proposed work.
B. Principle of the Circuit Operation
Mode 1: In Fig.2, as soon as Sw is turned on, the voltage
across L is the input voltage vi, thereby causing L to be
magnetized. At the same time, Cb is charged and the energy
required by the load is supplied from Co. Hence, there exist
three power flows in this mode. One is fro m the input via Sw
through L and then to the ground; another is from the input
via Sw through Cb and then to Df and the ground; the other is
from Co to Ro. The corresponding differential equations can
be represented by
A. Vignesh Raja, PG Scholar ME Power Electronics & Drives,
Prathyusha Institute of Technology & Management, Chennai – 602105.
S. Krishna Kumar, Senior Lecturer Department of EEE, Prathyusha
Institute Of Technology & Management,, Chennai – 602105. Email:vigneshraja12@gmail.com
ISBN 978-93-82338-60-4 | © 2013 Bonfring
International Conference on Engineering and Technology - 2013
89
L=
------ (4)
L=
L = 7.4 mH
Fig.2: Negative Output KY Boost Converter Mode 1
Operation
Mode 2 : In Fig.3, as soon as Sw is turned off the voltage
across L is the input voltage vi minus the voltage vo on Cb,
thereby causing L to be demagnetized. At the same time, Cb is
discharged. And hence, there exists one power flo w in this
mode, which is fro m the input via Db through Cb and then L
and the output. The corresponding differential equations can
be represented by
Therefore, based on the given specifications and (4), the
minimu m value of L can be calculated to be 7.4μH and finally
is set to 10μH .
2. Design of Output Capacitor
As generally recognized, for the electrolytic capacitor to be
considered, the value of the product of the capacitance and the
equivalent series resistance is about 65μ . And hence, the
minimu m value of Co can be represented by
Co =
------ (5)
Co =
Co = 1560µH.
And hence, according to the given specifications and (5),
the min imu m value of Co can be calculated to be 1560μF and
eventually is set to 2200μF .
IV.
EXPERIMENTAL RESULT S
The KY converter based neuro fuzzy was designed
using the following specifications given below,
Design Parameters
Fig 3: Negative Output KY Boost Converter Mode 2
Operation
Parameter
Value
Unit
Input voltage
12
V
Co
2200
µF
L
10
µH
Cb
1000
µF
Ro
6
Ω
Settling time
14
Ms
Io
2
A
Vo
24
V
Po
24
W
1. Design of Inductor
Fs
195
KHz
Since the input power is equal to the output power for any
load, the minimu m value of the input inductor L can be
expressed to be
Kp
0.5
---
Ki
0.0625
---
According to the voltage-second balance, and (1) and (2),
the voltage conversion ratio of this converter operating in
CCM can be represented as
(3)
In fig 1, the output of the KY-Boost converter is taken and
is compared with the reference voltage to produce an error
voltage. This is given as one of the inputs to the neuro fuzzy
controller. The error voltage is taken to produce a change in
error voltage which is given as another input to the neuro
fuzzy controller. These two inputs are taken as inputs through
the fuzzifier and are trained inside the network and produce an
output to drive the Mosfet switch through the gate drive.
III.
DESIGN CONSIDERAT IONS
ISBN 978-93-82338-60-4 | © 2013 Bonfring
International Conference on Engineering and Technology - 2013
According to the above design parameters the inputs are
given in the closed loop controller. The input to the neuro
fuzzy controller is the error voltage(e) p roduced which is
obtained by comparing the output voltage of the KY-Boost
converter with the reference voltage and the change in
error(ce).These inputs are trained using grid partition to
generate the control signals. The output being the duty
cycle(D)wh ich then sent to the PWM block for generating the
control signal which is fed as switching signal for Mosfet
switch of the KY Boost converter. The output voltage VL and
output current IL are stored in MATLAB workspace. The
output current and output voltage waveform for open loop
controller for first-order KY Converter is shown below.
The output current and voltage waveforms are shown.
Fig4.Output Current for KY Controller
Fig.5. Output Vo ltage for KY Controller
The output current and voltage ripple for the closed loop
control circuit is shown in below figure
90
efficiency further mo re. and the size and the cost of the work
can also be reduced in the near future.
REFERENCES
[1]
H. B. Shin, J. G. Park, S. K. Chung, H. W. Lee and T. A. Lipo,
“Generalized steady-state analysis of multiphase interleaved boost
converter with coupled inductors,” IEE Proc. Electr. Power, no. 152,
vol.3, pp. 584-594, 2005.
[2] R. Giral, E. Arango, J. Calvent e and L. Martinez-Salamero, “Inherent
DCM operation of the asymmetrical interleaved dual buck-boost,” in
Proc. IEEE IECON Conf., 2002, vol. 1, pp. 129-134.
[3] F. L. Luo, “Positive output Luo converters voltage lift technique,” IEE
Proc. Electr. Power Appl., no. 146, vol. 4, pp. 415-432, 1999.
[4] Chen, Xiaofan, Luo, Fang Lin and Ye, Hong, “Modified positive output
Luo converter,” in Proc. IEEE PEDS Conf., 1999, vol. 1, pp. 450-455.
[5] F. L. Luo and H. Ye, “Negative output super-lift converters,” IEEE
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[6] F. L. Luo and H. Ye, “Positive output super-lift converters,” IEEE
Trans. Power Electron., vol. 18, no. 1, pp. 105-113, 2003.
[7] E. Vidal-Idiarte, L. Martinez-Salamero, J.Calvente, and A. Romero, “ An
H∞ control strategy for switching converters in sliding-mode current
control,” IEEE Trans. Power Electron., vol. 21, pp. 553–556, Mar.
2006.[18] D. Cortes, J. Alvarez, and J. Alvarez, “Robust control of the
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[8] Y. U. Hong, S. H. Jung, Y. J.Woo, B. K. Choi, and G. H. Cho, “ Singlequasi-PWM DC–DC converter with fast transient response comprising,
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[9] K. K. S. Leung and H. S. H. Chung, “State trajectory prediction control
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[10] K. I. Hwu and y. T . Yau, “KY Converter and Its Derivatives,” IEEE
T RANSACT IONS ON POWER ELECTRONICS, vol. 24, no. 1, 2009
[11] S. Joseph Jawahar, Dr. N. S. Marimuthu, N. Albert Singh, “ An NeuroFuzzy Controller for a Non Linear Power Electronic Boost Converter,”
in IEEE TRANSACT IONS ON INFORMATION and AUTOMATION,
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[12] J. S. R. Jang, C. T. Sun, E. Mijutani, “Neuro-Fuzzy and Soft Computing:
A Computational Approach to Learning and Machine Intelligence. –
Prentice Hall, 1997
Fig 6: Output Cu rrent and Voltage Ripple for the Closed
Loop Control
V.
CONCLUSION AND FUTURE W ORK
This KY converter based neuro fuzzy concludes that the
output voltage ripple has been reduced from 60mv to 3mv
when compared with the output waveforms for the open loop
and closed loop control in both the conventional and the
proposed circuit. The measured waveform and the
experimental waveform are nearly the same. The above
waveforms are produced related to the PWM gate driving
signal. The output voltage ripple waveforms shows clearly that
the measured output voltage ripple is nearly 3 mv.
In the future others can use an upcoming modern
converters to reduce the output current and voltage ripple
further down and works very accurately and increases its
ISBN 978-93-82338-60-4 | © 2013 Bonfring