This document describes a project to design a closed loop high static gain step-up DC-DC converter with magnetic coupling based on a modified SEPIC converter. The project aims to present a topology with low switch voltage and high efficiency for low input voltage and high output voltage applications. A hybrid PSOGSA algorithm is used for controller design. Hardware circuits are developed and tested, achieving an output voltage of 300V from an input of 15V with 92.2% efficiency using magnetic coupling, compared to 150V output without coupling.

1. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
A MODIFIED CLOSED LOOP
CONTROL OF HIGH STATIC GAIN
SEPIC CONVERTER WITH
MAGNETIC COUPLING
FOR RENEWABLE APPLICATIONS
BATCH MEMBERS:
MURALI KRISHNAN L
(312811105021)
VIGNESH R
(312811105047)
VIGNESH V
(312811105048)
GUIDED BY
Mr.D JOHN SUNDAR
(AP/EEE)

2. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
PRESENTATION OUTLINE
 ABSTRACT
 OBJECTIVE
 MOTIVATION
 PROBLEM STATEMENT
 LITERATURE REVIEW
 BLOCK DIAGRAM
 SIMULATION CIRCUIT
 DESCRIPTION OF HYBRID PSAGSO ALGORITHM
 WAVEFORMS
 HARDWARE CIRCUITS
 RESULTS
 CONCLUSION

3. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
ABSTRACT
A high static gain step-up dc–dc converters based on the modified
SEPIC Converter is presented in this paper. The proposed topologies
present low switch voltage and high efficiency for low input voltage
and high output voltage applications. The configurations with
magnetic coupling is presented and analyzed. The magnetic coupling
allows the increase of the static gain maintaining a reduced switch
voltage. The experimental prototypes were developed with an input
voltage equal to 15 V and an output power equal to 100 W. The
efficiency at nominal power obtained with the prototype without
magnetic coupling was equal to 91.9% with an output voltage of
150V and with magnetic coupling operating with an output voltage
equal to 300 V, presents efficiency equal to 92.2%.

4. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
OBJECTIVE
 To design a closed loop high static gain step-up DC-DC
converter with magnetic coupling based on the modified
SEPIC converter .
 To present a topology with low switch voltage and high
efficiency for low input voltage and high output voltage
applications.

5. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
MOTIVATION
 Electricity demand is the major concern in the world
today.
 To meet the demand the number of natural sources comes
under electricity production.
 Among those sources solar energy is considered as it is
most readily available and free source of energy since
prehistoric times.
 It is estimated that solar energy equivalent to over 15,000
times the world's annual commercial energy consumption
reaches the earth every year.
 Single ended primary inductor with solar energy is
considered for the improvement of power generation.

6. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
PROBLEM STATEMENT
 In SEPIC converter the voltage at its output to be greater
than, less than or equal to that its input, whereas in high
static gain SEPIC converter the output voltage is higher
than its input voltage.
 The magnetic coupling allows the increase of static gain
maintaining a reduced switch voltage

7. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
LITERATURE REVIEW
(D. Meneses, F. Blaabjerg, O. Garcia, and J. A. Cobos, “Review and comparison of step
up transformerless topologies for photovoltaicAC-Module application,” IEEE Trans.
Power Electron., vol. 28, no. 6, pp. 2649–2663, Jun. 2013.)
 This paper presents a comprehensive review of step-up
single-phase non-isolated inverters suitable for ac-module
applications. In order to compare the most feasible solutions
of the reviewed topologies, a benchmark is set.
(C. W. Li and X. He, “Review of non-isolated high step-up DC/DC converters in photovoltaic grid-
connected applications,” IEEE Trans. Ind. Electron., vol. 58, no. 4, pp. 1239–1250, Apr. 2011.)
 This paper is concerned with how to achieve high-step-up,
low-cost, and high-efficiency dc/dc conversion which is the
major consideration due to the low PV output voltage with the
parallel-connected structure. The limitations of the
conventional boost converters in these applications are
analyzed.

8. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
LITERATURE REVIEW
(D. Zhou, A. Pietkiewicz, and S. Cuk, “A Three-Switch high-voltage converter,” IEEE
Trans. Power Electron., vol. 14, no. 1, pp. 177–183, Jan.)
 A novel single active switch two-diodes high-voltage converter is
presented. This converter can operate into a capacitor-diode voltage
multiplier, which offers simpler structure and control, higher
efficiency, reduced electromagnetic interference (EMI), and size
and weight savings compared with traditional switched-mode
regulated voltage multipliers.
(E. H. Ismail, M. A. Al-Saffar, A. J. Sabzali, and A. A. Fardoun, “A family of single-
switchPWM converters with high step-up conversion ratio,” IEEE Trans. Circuits Syst. I,
Reg Papers, vol. 55, no. 4, pp. 1159–1171,)
 A new family of a single-switch three-diode dc-dc pulse
width-modulated (PWM) converters operating at constant
frequency and constant duty cycle is presented in this paper.
The proposed converters are different from the conventional
dc-dc step-up converters, and they posses higher voltage gain
with small output voltage ripples.

9. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
BLOCK DIAGRAM
SOLAR PANELARAY Vdc Vac Vgrid
MPPT Vpv SEPIC Vload
CONVERTER
AC GRID
DG INTERFACED GRID CONNECTED SYSTEM WITH
DISTRIBUTED GENRATOR (SOLAR , WIND , FUEL CELL…)
DC/DC DC/AC FILTER
LOAD

10. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
OPEN LOOP CONFIGURATION
Vdc Vload
SOLAR
PANEL
SEPIC
CONVERTER
DC/DC
LOAD

11. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
CLOSED LOOP CONFIGURATION
PWM PULSE FOR
MOSFET SWITCH
CONTROL SIGNAL ERROR Vact
Vset
PANEL CONVERTER LOAD
PWM
GENERATION
PI CONTROLLER
VOLTAGE
SENSOR+

12. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
STIMULATION CIRCUIT

13. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
HYBRID PSOGSA ALGORITHM
 A new hybrid population-based algorithm (PSOGSA) is
proposed with the combination of Particle Swarm
Optimization (PSO) and Gravitational Search Algorithm
(GSA).
 The main idea is to integrate the ability of exploitation in
PSO with the ability of exploration in GSA to synthesize
both algorithms’ strength.

14. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
HYBRID PSOGSA FLOWCHART

15. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
HYBRID PSOGSA ALGORITHM
 In PSOGSA, at first, all agents are randomly initialized.
Each agent is considered as a candidate solution. After
initialization, Gravitational force, gravitational constant,
and resultant forces among agents are calculated. After
that, the accelerations of particles are defined as,
 In each iteration, the best solution so far should be
updated. After calculating the accelerations and with
updating the best solution so far, the velocities of all
agents can be calculated. Finally, the positions of agents
are defined as,

16. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
HYBRID PSOGSA ALGORITHM
 The process of updating velocities and positions will be
stopped by meeting an end criterion.
 The steps of PSOGSA are represented in figure above.
 The agents near good solutions try to attract the other
agents which are exploring the search space.
 When all agents are near a good solution, they move very
slowly. In this case, the gBest help them to exploit the
global best.
 PSOGSA use a memory (gBest) to save the best solution
has found so far, so it is accessible anytime.
 Each agent can observe the best solution so far and tend
toward it. With adjusting weighting factors , the abilities of
global search and local search can be balanced.

17. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
GATE PULSE GENERATION

18. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
INPUT OUTPUT WAVEFORM

19. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
HARDWARE CIRCUIT

20. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
SPECIFICATIONS
S.NO PARAMETERS SPECIFICATIONS
1. DIODE IN7004
2. POWER MOSFET IRFP460
3. OPTO ISOLATORS PC817
4. MICROCONTROLLER PIC16F877A
5. VOLTAGE REGULATOR IC7812

21. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
HARDWARE KIT WITH OUTPUT

22. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
OVERALL HARDWARE KIT
COUPLING
INDUCTOR
CONVERTER
CIRCUIT
SENSING
CIRCUIT
MOTHER
BOARD
TRIGGERING
CIRCUIT

23. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
CONVERTER CIRCUIT
DIODE( IN4007 )
POWER MOSFET
(IRFP460) WITH
HEAT SINK
FUSE

24. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
MOTHER BOARD
LCD
DISPLAY
OSCILLATOR
RESET KEY
(PIC16F877A )
MICRO
CONTROLLER
REGULATOR
START AND
STOP KEY

25. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
SENSING CIRCUIT
OUTPUT VOLTAGE
SENSOR
INPUT CURRENT
SENSOR
INPUT VOLTAGE
SENSOR
OPAMP

26. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
TRIGGERING CIRCUIT
DIODE ( IN4007)
RECTIFIER
CIRCUIT
OPTO ISOLATOR
(PC817)
REGULATORS

27. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
RESULT
PARAMETERS SEPIC
CONVERTER
WITHOUT
MAGNETIC
COUPLING
SEPIC CONVERTER
WITH MAGNETIC
COUPLING
INPUT VOLTAGE(Vi) 15 V 15 V
OUTPUT VOLTAGE(Vo) 150 V 300V
OUTPUT POWER (Po) 100 W 100 W
SWITCHING
FREQUENCY
24 KHZ 24 KHZ
DUTY CYCLE (D) 0.82 0.82
SWITCH VOLTAGE(Vs) 83 83
STATIC GAIN (q) 10 20

28. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
CONCLUSION
 A new topologies of nonisolated high static gain converters are
presented.
 The structure with magnetic coupling can operate with static gain
higher than 20 maintaining low the switch voltage.
 The efficiency of the proposed converter with magnetic coupling is
equal to 92.2% operating with input voltage equal to 15V, output
voltage equal 300V, and output power equal 100W.
 The commutation losses of the proposed converter with magnetic
coupling are reduced due to the presence of the transformer leakage
inductance and the secondary voltage multiplier that operates as a
non dissipative clamping circuit to the output diode voltage

29. A G N I C O L L E G E O F T E C H N O L O G YD E P A R T M E N T O F E E E
THANK YOU