Implementation and Design of Advanced DC/AC Inverter for ...Implementation and Design of Advanced...

Implementation and Design of Advanced DC/AC

Inverter for Renewable Energy

Ergun Ercelebi and Abubakir Aziz Shikhan Electrical and Electronic Engineering, Gaziantep University, Turkey

Email: ergun.ercelebi, [email protected]

Abstract—An inverter is a major component of standalone

solar photovoltaic (PV) system for combining with photo

voltaic or battery. In this paper 600W high efficiency (%95)

advanced inverter relevant to PV system has been designed

and implemented. the system consist of two parts; the first is

the synchronous DC-DC boost converter with variable input

voltage from 9V to 60V and constant DC voltage of 80V,and

second is a DC-AC inverter (voltage source inverter). The

sinusoidal bipolar SPWM is used for triggering the gates of

the inverter bridge. The dsPIC16F877A microcontroller

type is used for the implementation of the inverter system.

The MATLAB Simulink environment is used for simulation

the system. The simulation and experimental results show

the stable operation and the results obtained satisfy the

system.

Index Terms—MATLAB Simulink, converter, dc/ac inverter

I. INTRODUCTION

The classical power systems such as big power

generation plants are located at sufficient geographical

locale produce most of the electrical power, which is then

transferred to large consumption centres’ over long

distance transmission lines. The system control centres’

observe and regulate the power system continuously to

ensure the quality of the power, rated voltage and

frequency. But, now the complete power system is

changing, a large number of generation units, including

both non-renewable and renewable sources such as wind

turbines, wave generators, photovoltaic (PV) generators,

are being developed, and installed. A wide-spread use of

renewable energy sources in distribution networks and a

high breakthrough level will be seen in the near future

many places [1]. The dc-ac converter, also called as the

inverter, converts dc source to ac source at desired output

voltage and frequency according the system. The dc

power input to the inverter is obtained from a present

power supply network or from a rotating alternator

through a rectifier or a battery fuel cell, photovoltaic

array, or magneto hydrodynamic generator [2], [3]. PWM

control is the robust technique that offers a simple

process for controlling of analog systems with the

processor’s digital output. With the availability of

minimum cost high performance DSP chips characterized

by the execution of most instructions in one instruction

cycle, intricate control algorithms can be executed with

Manuscript received January 11, 2015; revised May 8, 2015.

fast speed, making very high sampling rate possible for

digitally-controlled inverters [4]. The AC output voltage

could be constant or variable frequency and voltage. This

conversion can be achieved either by controlled turn on

and turn off electronic switch (e.g. MOSFET, IGBT and

BJT, etc.) or by forced commutated thyristors, depending

on application. In the ideal inverter the output voltage

waveform of should be sinusoidal [5]. Fig. 1 is over all

diagram of synchronous dc-ac inverter. The related works;

Have used a Matlab Simulink model of a single-phase

full bridge 2kVA Voltage Controlled Voltage Source

Inverter in [6]. Development of control circuit for single

phase inverter using ATMEL microcontroller Proposed in

[3]. A new dc to dc boost converter using closed loop

control proportional Integral (PI) and Derivative (D)

mechanism for photovoltaic (PV) standalone high voltage

applications presented in [7]. Designed a boost converter

that was able to boost up a variable DC voltages to a

controlled DC voltage with desired output voltage value

proposed in [8]. A multi-input single-phase grid-

connected inverter for a hybrid photovoltaic (PV)/wind

power system Proposed in [9]. In this paper I designed,

simulated and implemented experimentally a 600W DC-

AC converter, which take from a photovoltaic solar panel

model vary from (9-60) Volt and constant output voltage

of according set point reference (Vref) from (24-80) Volt.

Figure 1. Over all diagram of synchronous dc-ac inverter

II. DC-DC BOOST CONVERTER

The synchronous boos DC-DC converter is used to

obtain a constant output voltage with variable input

voltage. It’s mainly used to the stabilization dc power

supplies. The average output voltage of converter is

always larger than the input voltage. The switching duty

cycle controlled the output voltage of converter. When

the switch is ON, the diode is reverse biased, and hence

isolates the output stage of converter. During the switch

ON the inductor gets the energy from the source and

International Journal of Electrical Energy, Vol. 3, No. 1, March 2015

©2015 International Journal of Electrical Energy 32doi: 10.12720/ijoee.3.1.32-36

stores it. During switch OFF case, the diode is forward

biased and the output side receives the storage energy

from the inductor as well as the input. Thus the energy

transferred to the output from input is always greater in a

given switching cycle. The ratio of output voltage to

input voltage is given by;

1

1

O

I

V

V D

(1)

where, Vin and Vo are the input and output voltages of the

boost converter, respectively, and D is the duty ratio and

defined as the ratio of the on time of the switch to the

total switching period [10], [11].

The Maximum duty cycle

(min)1

VinD

Vout

(2)

where, VIN (min), VOUT, and, η are the minimum input and

output voltages and η is efficiency of the converter

estimated 95%. The Inductor Ripple Current Estimation:

out(max)(0.2 0.4) ILVout

I toVin

(3)

where, D, fs, ΔIL, IOUT(max) are duty cycle, minimum

switching frequency of the converter, inductor ripple

current and maximum output current necessary

respectively. The maximum switch current:

out(max)I(max)

2 1

ILIsw

D

(4)

Inductor Calculation: (L is selected inductor value):

out )Vin (V Vin

L Fs VoutL

I

(5)

Output Capacitor Selection, The maximum output

voltage ripple ΔVOUT, (ΔVout=desired output voltage

ripple) [12].

0.01Vout Vout (6)

(min)Iout(max)

outD

FsC

Vout

(7)

A. Simulation Model for Boost Converter

The converter is designed using one MOSFET, anti-

parallel diode, rectifier diode, inductor and capacitor with

the PI feedback control in Simulink. The MATLAB

Simulation of synchronous DC-DC boost converter is

shown in Fig. 2. The inductance and capacitance are

42µH and 940μF respectively.

Figure 2. MATLAB simulation synchronous boost converter

Control design for a boost PWM converter involves

two steps: choice of modulation strategy, which

corresponds to an open-loop boost converter control, and

design of dynamic closed loop control. The instantaneous

voltage control scheme is applied to the proposed circuit.

The block diagram is shown in Fig. 3, of the control

circuit. The output voltage is compared with a reference

voltage Vr. Hence, the control scheme is simple

compared with others.

The classic PI (proportional-integral) controller has

been used in many industrial control systems, mainly due

to its simple structure that can be easily understood and

implemented in practice, and its excellent flexibility

made possible by adjustment of the coefficients KP, and

KI [6], [7].

Figure 3. MATLAB simulation PI controller feedback and set point

(a)


©2015 International Journal of Electrical Energy 33

(b) Figure 4. Overall diagram dc-dc converter

B. The Implemental DC-DC Booster

The schematic diagrams for the Prototype synchronous

dc-dc boost converter circuit shown in Fig. 4a and Fig. 4b

respectively. The feedback controller concludes UC3843

used current mode controller and LM358 operation

amplifier, and output port 6 of UC3843 fed the MOSFET.

In the power circuit of Fig. 4, the input capacitor 1000μF

and output capacitor tow 470μF connected in parallel to

decrease the ESR (equivalent series resistance). The

prototype synchronous boost converter is shown in Fig. 5.

Figure 5. Photograph DC-DC synchronous boost converter

Table I lists the recorded output voltage. The dc output

voltage is measured by Voltmeter, with varying input

voltage and is found to be constant according set point.

TABLE I. SHOWS THE RECORDED OUTPUT VOLTAGE WITH VARY

REFERENCE VOLTAGE (SET POINT)

Vin Vrf Vo Vin Vrf Vo Vin Vrf Vo

9 24 24 12 48 48 12 60 60

12 24 24 18 48 48 18 60 60

14 24 24 24 48 48 25 60 60

18 24 24 28 48 48 35 60 60

20 24 24 30 48 48 40 60 60

22 24 24 35 48 48 50 60 60

III. THE INVERTER

A. Simulation Model of PWM Inverter

The single-phase full bridge inverter is constructed

using 4 IGBT switches and 4 anti-parallel diodes in

Simulink. In the model, sinusoidal wave at 50-Hz and

carrier wave are compared to generate PWM signals.

PWM inverter uses self-commutating IGBT solid-state

power electronic switches. The switching frequency of

the inverter is 2KHz. The single-phase inverter is fed

from 48Vsynchronous boost converter. LC filter blocks

high frequency harmonics caused by DC to AC

conversion to reduce distortion in the output harmonic.

The inductance and capacitance of the filter is 5mH and

470μF respectively and non-leaner load 12Ω 5mH is used.

The Simulink model is shown in Fig. 6.

Figure 6. The simulation model full bridge inverter



B. The Experimental Implement of The PWM Inverter

The schematic diagrams for inverter, as shown in Fig.

7, which is consist of power circuit and control circuit.

The PIC microcontroller16F877A is used to generate the

required SPWM signals to drive and switch the full-

bridge IGBTs switches, SPWM and output ports are used

for the implementation. The four PWM signals have been

fed to the optocoupler (NPN 4N25) for the isolation of

gate drivers. Four discrete IGBTs (G4PC30UD) are used

as switching devices.

Figure 7. The implementation full bridge inverter

IV. SIMULATION AND EXPERIMENTAL RESULTS

The simulation results obtain from the Matlab

Simulink DC-DC converter and DC-AC inverter model

developed and that were compared with experimental

results for the 600W inverter are shown Fig. 8-Fig. 11.

0.9965 0.9966 0.9967 0.9968 0.9969 0.997 0.9971 0.9972 0.9973 0.9974 0.997547.995

48

48.005Vout

0.9965 0.9966 0.9967 0.9968 0.9969 0.997 0.9971 0.9972 0.9973 0.9974 0.99750

0.5

1

0.9965 0.9966 0.9967 0.9968 0.9969 0.997 0.9971 0.9972 0.9973 0.9974 0.99752.0868

2.087

2.0872

0.9965 0.9966 0.9967 0.9968 0.9969 0.997 0.9971 0.9972 0.9973 0.9974 0.99755

10

15

0.9965 0.9966 0.9967 0.9968 0.9969 0.997 0.9971 0.9972 0.9973 0.9974 0.997511

12

13

Time sec

Vin

Vo

MOSFET Triguring

Io

Iin

Figure 8a. Vin 12 set point voltage 48

0.9965 0.9966 0.9967 0.9968 0.9969 0.997 0.9971 0.9972 0.9973 0.9974 0.997547.998

48

48.002Vout

0.9965 0.9966 0.9967 0.9968 0.9969 0.997 0.9971 0.9972 0.9973 0.9974 0.99750

0.5

1

0.9965 0.9966 0.9967 0.9968 0.9969 0.997 0.9971 0.9972 0.9973 0.9974 0.99752.0868

2.087

2.0872

0.9965 0.9966 0.9967 0.9968 0.9969 0.997 0.9971 0.9972 0.9973 0.9974 0.99750

5

10

0.9965 0.9966 0.9967 0.9968 0.9969 0.997 0.9971 0.9972 0.9973 0.9974 0.997523

24

25

Time sec

Vo

MOSFET Trigering

Io

Iin

Vo

Figure 8b. Vin 24 set point voltage 48

0.9965 0.9966 0.9967 0.9968 0.9969 0.997 0.9971 0.9972 0.9973 0.9974 0.997547.998

48

48.002Vout

0.9965 0.9966 0.9967 0.9968 0.9969 0.997 0.9971 0.9972 0.9973 0.9974 0.99750

0.5

1

0.9965 0.9966 0.9967 0.9968 0.9969 0.997 0.9971 0.9972 0.9973 0.9974 0.99752.0868

2.0869

2.087

0.9965 0.9966 0.9967 0.9968 0.9969 0.997 0.9971 0.9972 0.9973 0.9974 0.99750

5

10

0.9965 0.9966 0.9967 0.9968 0.9969 0.997 0.9971 0.9972 0.9973 0.9974 0.997535

36

37

Time sec

Vo

MOSFET Trigering

Io

Iin

Vin

Figure 8c. Vin 36V set point voltage 48

Figure 9. Vin 12V set point voltage 48

0 0.005 0.01 0.015 0.02 0.025 0.03 0.035 0.04-50

0

50V inverter

0 0.005 0.01 0.015 0.02 0.025 0.03 0.035 0.04-5

0

5

Time sec

I load

Figure 10. Dc-Ac inverter without fillter inMATLAB simulation

Figure 11. Dc-Ac inverter without fillter practical

Fig. 8a, Fig. 8b and Fig. 8c show the output voltage,

pulses, output current and input current for input voltage

24V, 36V, 48V respectively. Fig. 9 shows the

experimental result. Fig. 10 and Fig. 11 show the output

voltage and current of the inverter for the simulation

result and experimental result without the filter and Fig.

12 and Fig. 13 show the output voltage and current with

LC filter.



0 0.005 0.01 0.015 0.02 0.025 0.03 0.035 0.04 0.045 0.05-50

0

50Vo

0 0.005 0.01 0.015 0.02 0.025 0.03 0.035 0.04 0.045 0.05-10

-5

0

5

10

Time

I load

Figure 12. Dc

Figure 13. Dc-Ac inverter with LC fillter practical

V. CONCLUSION

This paper presented the simulation model using

Simulink-Matlab and an implementation experimental

design prototype for DC-AC converter. The simulation

results show the ability of the controller to obtain the

constant output voltage for boost converter at different

input voltage. Also the inverter simulation shows that the

AC voltage obtained is approximately sinusoidal

waveform. The experimental results and simulation

results are very close to the others.

REFERENCES

[1] IOV, et al., “Power electronics and control of renewable energy

systems,” in Proc. 7th International Conference on Power Electronics and Drive Systems, 2007, pp. 6-28.

[2] P. Bhangale, P. Sonare, and S. Suralkar, “Design and

implementation of carrier based sinusoidal PWM inverter,” International Journal of Advanced Research in Electrical,

Electronics and Instrumentation Engineering, vol. 1, no. 4, Oct.

2012. [3] B. Ismail, et al., “Development of control circuit for single phase

inverter using Atmel microcontroller,” in Proc. International

Conference on Man-Machine System, 2006.‏

[4] M. Tümay, K. Ç. Bayindir, M. U. Cuma, and A. Teke. (2004). Experimental setup for a DSP based single-phase PWM inverter.

[Online]. Available:

http://emo.org.tr/ekler/4c76e43c96a0124_ek.pdf. [5] R. Senthilkumar and M. Singaaravelu. “Design of single phase

inverter using dspic30f4013,” International Journal of

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[6] A. B. Sankar and R. Seyezhai, “MATLAB simulation of power

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Electrical, Electronics, Instrumentation and Control Engineering,

vol. 1, no. 8, Nov. 2013. [7] D. S. Karanjkar, et al., “Performance analysis of fractional order

cascade controller for boost converter in solar photo-voltaic

system,” in Proc. International Conference on Engineering, ‏Dec. 2012, pp. 1-6.

[8] J. Faiz and G. Shahgholian, “Modeling and simulation of a three-

phase inverter with rectifier-type nonlinear loads,” Armenian Journal of Physics., vol. 2, no. 4, pp. 307-316, Sep. 2009.

[9] R. Arulmurugan and N. S. Vanitha, “Optimal design of DC to DC

boost converter with closed loop control PID mechanism for high voltage photovoltaic application,” International Journal of Power

Electronics and Drive Systems (IJPEDS), vol. 2, no. 4, pp. 434-

444, Dec. 2012. [10] K. H. Mohamed, T. B. Ibrahim, and N. B. Saad, “Boost converter

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[11] Y. Yang, et al., “Multi-Input single-phase grid-connected inverter for hybrid PV/wind power system,”‏ International Journal of

Renewable and Sustainable Energy, vol. 3, no. 2, pp. 35-42, Feb.

2014. [12] B. Hauke. Basic calculation of a boost converter’s power stage.

[Online]. Available:

http://www.ti.com/lit/an/slva372c/slva372c.pdf

Ergun Ercelebi received B.S. degree in

Electrical and Electronics Engineering from METU, Gaziantep, Turkey in 1990 and M.S.

and Ph.D. degrees in Electrical and Electronics

Engineering from University of Gaziantep in 1992 and 1999 respectively. He was the head

of Computer Engineering, University of

Gaziantep between 2003 and 2004. He is presently Professor and head of dept of

electrical electronics department, University of

Gaziantep. His research interests include speech processing, image processing, adaptive filters, neural networks,

statistical signal processing wavelet.

Abubakir Aziz Shikhan received B.Sc.

degrees in Electrical Engineering from

Technical College, MOSUL, IRAQ, in 2003

and 2007, now master student in electric and

Electronic Engineering Gaziantep University. During 2007-2013, he stayed in machine and

power electronics Laboratory, electric

department in technology institute, Ministry of higher education and scientific research of

Erbil, Iraq.



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