Stand alone regulated single phase five level inverter with coupled inductor

Proceedings of the International Conference on Emerging Trends in Engineering and Management (ICETEM14)

30-31, December, 2014, Ernakulam, India

248

STAND-ALONE REGULATED SINGLE PHASE FIVE

LEVEL INVERTER WITH COUPLED INDUCTOR

JOHN NINAN1, JASNA S.B

2, VIDHYA K.G

3

1Department of Electrical Engineering, Vidya College of Engineering Thrissur



ABSTRACT

Energy demand is increasing day by day. To meet this renewable energy sources have to be incorporated.

Renewable energy sources like PV cells, fuel cells produce DC voltage. For house hold purpose and industrial purpose

this DC (direct current) voltage has to be converted into AC (alternating current) voltage. For this power electronic

inverters are used. Multilevel inverters has got wide spread acceptance as it can synthesis almost sinusoidal wave form.

This paper presents an inverter which can give a five level AC output without variation in it’s voltage amplitude, from a

variable DC source. Here a high step-up converter is introduced as a front-end stage. This DC-DC conversion helps to

stabilize the output voltage. A coupled inductor is introduced to get a five level AC output. The working principle of DC-

DC converter and the inverter are explained. The circuit is tested with different DC voltage and found to give the same

output voltage waveform. The circuit has been simulated using MATLAB/Simulink tool and a prototype is made to

verify the validity and performance of the circuit.

Keywords: Coupled Inductor, DC-DC Converter, Multilevel Inverter

I. INTRODUCTION

For delivering premium electric power in terms of high reliability and power quality, from DERs like PV cells,

fuel cells; an interface is needed to boost up and to convert the low voltage variable DC (direct current) voltage to a

constant amplitude AC (alternating current) voltage [1]-[3]. For this a cascaded converter-inverter topology is used [16].

Converters with coupled inductors have emerged displaying a high efficiency, a low overall component count, a simple

topology and with single switch [4]. The conventional flyback DC-DC converter topology have the leakage components

that cause stress and loss of energy that result in low efficiency. For higher boost ratio converter with a voltage multiplier

and a coupled inductor is used [5]. But when the input voltage range is wide, the duty cycle needs to stretch to the upper

or lower limit. The switched capacitor converter or the charge pump converts the low voltage to step up voltage using

only switches and capacitors [6]. The reference [17] proposed a circuit which combines the behaviour of three different

converter topologies: boost, flyback, and charge pump.

In the inverter section, multilevel inverters are used. As the output voltage level increases, the output harmonic

content of such inverters decreases, allowing the use of smaller and less expensive output filters [13], [14]. The most

popular single phase multilevel topologies are the diode-clamped, capacitor clamped and cascaded types [7], [8]. There

exist many other topologies. So multilevel inverter topologies can be classified into two types: Type I and Type II. Type I

uses multiple DC voltage sources and Type II uses multiple (split or clamping) DC voltage capacitors [9]. As the level

increases, the required number of DC sources also increases in Type I. This made the use of Type I a limited one. Type II

is limited mainly by the balancing of the capacitor voltages. So the most desirable topology may be a multilevel inverter

with single source and no split capacitor.

INTERNATIONAL JOURNAL OF ELECTRICAL ENGINEERING &

TECHNOLOGY (IJEET)

ISSN 0976 – 6545(Print) ISSN 0976 – 6553(Online) Volume 5, Issue 12, December (2014), pp. 248-260 © IAEME: www.iaeme.com/IJEET.asp Journal Impact Factor (2014): 6.8310 (Calculated by GISI) www.jifactor.com

IJEET

© I A E M E



249

Multilevel inverters with coupled inductors need only one source besides split capacitors are not required. For

the inverter with coupled inductor, a three limb coupled inductor is the most desirable one, however coupled inductor

with high inductance value is not preferred [10]. The analysis of the coupled-inductor designs in [11] suggests that

reducing the target inductance of the coupled inductor could improve the overall balance of losses in the coupled

inductor, with only a minor increase in ripple current. The number of voltage levels can be increased by using a split-

wound coupled inductor within each inverter-leg and using interleaved pwm switching of the upper and lower switches

[12]. The reference [15] proposed a circuit which increase the output current, while the switched current through the HF

power devices is reduced. The coupled inductor provides excellent protection against dc-rail shoot-through conditions.

The paper is organized as follows. In Section 2 the operation principles of converter and inverter are explained.

In Section 3 simulation and their results are presented. Finally, experimental results and conclusions are given in Section

4 and Section 5.

2. BASIC OPERATIONAL PRINCIPLES

The circuit used in this paper can synthesis a constant amplitude five level AC voltage from a varying DC

source. The basic block diagram is given in the Fig. 1.

This topology configuration consists of a high step-up DC-DC converter and a simplified multilevel inverter. By

using the independent voltage regulation control of the high step-up converter, the output of the inverter can be made a

constant amplitude five level AC voltage. The Fig. 2 is the overall circuit diagram. The operation mechanism of DC-DC

converter and the inverter is discussed separately.

Fig. 1: Overall System Block Diagram

Fig. 2: Main circuit diagram

Proceedings of the International Conference on Emerging Trends in Engineering and Management

2.1 HIGH STEP-UP DC-DC CONVERTER

In this paper, a high step-up converter is used as a front

output DC voltage of various DERs such as photovoltaic and fuel cell modules for use with

Fig. 3: Circuit diagram of the DC

The circuit diagram of the high step

coupled inductor, three diodes, and three capacitors. The converter combines boost, flyback and charge

to attain high voltage gain. The coupled inductor is

turns ratio of NS:NP , primary leakage inductor L

Five modes of operations are there for this circuit. The

waveform vgs is the gating signal of the active switch S; i

the primary leakage inductor; iLm is the current of the magnetizing inductor L

leakage inductor; the vds is the drain-to-source voltage of the active switch S; the v

Cc; the vDo is the voltage of the output diode D

the voltage waveform of the magnetizing inductor L

Fig. 4: Key waveform of high step up converter [17].

International Conference on Emerging Trends in Engineering and Management


250

DC CONVERTER

up converter is used as a front-end stage to boost the DC voltage and to stabilize the

output DC voltage of various DERs such as photovoltaic and fuel cell modules for use with the multilevel inverter.

Fig. 3: Circuit diagram of the DC-DC converter

The circuit diagram of the high step-up converter is given in the Fig. 3. It consists of one power MOSFET, one

coupled inductor, three diodes, and three capacitors. The converter combines boost, flyback and charge

n. The coupled inductor is modelled as a magnetizing inductor Lm, an ideal transformer with a

, primary leakage inductor LLk1 and secondary leakage inductor LLk2.

Five modes of operations are there for this circuit. The key wave form is given in the Fig. 4. The voltage

is the gating signal of the active switch S; iCc is the current of the clamp capacitor C

is the current of the magnetizing inductor Lm; the iLK2 is the current of the secondary

source voltage of the active switch S; the vCc is the voltage of the clamp capacitor

is the voltage of the output diode Do; the vCpump is the voltage of the charge pump capacitor C

the voltage waveform of the magnetizing inductor Lm.

Fig. 4: Key waveform of high step up converter [17].

International Conference on Emerging Trends in Engineering and Management (ICETEM14)

, December, 2014, Ernakulam, India

end stage to boost the DC voltage and to stabilize the

the multilevel inverter.

up converter is given in the Fig. 3. It consists of one power MOSFET, one

coupled inductor, three diodes, and three capacitors. The converter combines boost, flyback and charge-pump topologies

, an ideal transformer with a

form is given in the Fig. 4. The voltage

is the current of the clamp capacitor Cc; iLK1 is the current of

is the current of the secondary

is the voltage of the clamp capacitor

p capacitor Cpump; the vLm is


2.1.1 MODE-1 (t0 < t <t1)

In this mode MOSFET is turned ON.

increases on primary side. The energy is stored in the primary winding. The output diode D

2.1.2 MODE-2 (t1 < t <t2) In mode-2, the MOSFET is turned OFF. Two paths are created to complete the circuit: throgh C

Cpump. The primary leakage current decreases. The secondary current increases. The energy in the leakage inductance of

the primary side is recycled. In this mode output diode D

2.1.3 MODE-3 (t2 < t <t3)

In this mode the Cc completely charged and thus D

windings are in series. The primary current

energy of the source, pump capacitor and the coupled inductor is given as the output.



251

In this mode MOSFET is turned ON. Voltage is applied to the transformer primary side.The leakage current

increases on primary side. The energy is stored in the primary winding. The output diode Do is turned OFF.

Fig. 5: Mode 1

2, the MOSFET is turned OFF. Two paths are created to complete the circuit: throgh C

. The primary leakage current decreases. The secondary current increases. The energy in the leakage inductance of

In this mode output diode Do is ON and pump diode Dpump is OFF.

Fig. 6: Mode 2

completely charged and thus Dc turned OFF. Therefore Cpump

windings are in series. The primary current is continuous and is decreasing. In this mode, diode D

energy of the source, pump capacitor and the coupled inductor is given as the output.

Fig. 7: Mode 3



Voltage is applied to the transformer primary side.The leakage current

is turned OFF.

2, the MOSFET is turned OFF. Two paths are created to complete the circuit: throgh CC and through

. The primary leakage current decreases. The secondary current increases. The energy in the leakage inductance of

is OFF.

pump, primary and secondary

and is decreasing. In this mode, diode Do is in ON state and the



252

2.1.4 MODE-4 (t3 < t <t4)

In this mode the MOSFET is turned ON. It creates a new path for Cc to discharge: through the Cpump. Primary

leakage current increases and the secondary current decreases. The output diode Do is ON.

Fig. 8: Mode 4

2.1.5 MODE-5 (t4 < t <t5)

In this mode MOFET remains ON. The secondary current decreases to zero, output diode turns off. Cc continues

the discharging through the pump diode and Cpump. The primary current iLk1 increases. At t5, voltage of Cpump equals

voltage of Cc, and the state returns to initial condition.

Fig. 9: Mode 5

According to the voltage seconds balance condition of the magnetizing inductor; the voltage of the primary winding can

be derived a

vpri = vin �

�� (1)

where Vin represents the low voltage dc energy input and the voltage of the secondary winding is

vsec = vpri

��

�� = vin

�

��

�� (2)

Similar to that of the boost converter, the voltage of the chargepump capacitor Cpump and clamp capacitor Cc can be

expressed as

vcp = vcc = vin �

�� (3)

Simplified voltage loop when output diode is on is given by the below figure.


Fig. 10: DC

Hence, the voltage conversion ratio of the high step

inv

v 0 = (2 +

2.2 FIVE LEVEL INVERTER

Fig

Fig. 11 shows the circuit of the single-phase five level inverter. 2E is the dc

inductors. The mutual inductance of the two inductors is M and the output terminals of this inverter are 1 and 2.

2.2.1 SWITCHING STATES FOR FIVE LEVEL OUTPUT VOLTAGE The power switches in one arm are assumed to switch

switch S2 must made OFF and vice versa. Similarly in case of S

given in the below table.

TABLE I: Switching states for five



253

Fig. 10: DC-DC converter when D0 is ON

ratio of the high step-up converter, named input voltage to bus voltage ratio is

+

p

s

N

N D) / (1-D) (4)

Fig. 11: Single-Phase Five-Level Inverter

phase five level inverter. 2E is the dc-link voltage and L


SWITCHING STATES FOR FIVE LEVEL OUTPUT VOLTAGE The power switches in one arm are assumed to switch complementarily. For an instant switch S

must made OFF and vice versa. Similarly in case of S3, S4 and S5, S6. The details of the switching state is

TABLE I: Switching states for five-level output voltage

S1 S3 S5 u12

1 0 0 +2E

1 0 1 +E

1 1 0 +E

1 1 1 0

0 0 0 0

0 0 1 -E

0 1 0 -E

0 1 1 -2E



up converter, named input voltage to bus voltage ratio is

link voltage and L1 and L2 are the coupled


complementarily. For an instant switch S1 is ON then the

, S6. The details of the switching state is



254

The number “1” is used to denote the ON state of one switch and “0” will be used to denote the OFF state.

There are mainly four switching states in this inverter circuit. In each case one of the upper switches or a combination of

the upper switches is made ON and similarly on the bottom switches. The assumption taken for explaining the cases are

the inductance L1, L2 of the coupled inductor are equal and the leakage inductance, Lk is zero.

2.2.1.1 Case-1 (+2E): In this case, the required output voltage level is +2E. To achieve this upper switch S1 is turned ON

along with the lower switches S4 and S6 are turned ON. The equivalent circuit becomes Fig. 12

Fig. 12: Equivalent circuit of case1

The inductors are parallel and opposing. So the net or equivalent inductance is

MLL

MLL

221

2

21

++ (5)

The inductance of the coupled inductor can be expressed as the sum of mutual inductance and the leakage

inductance. By considering the assumption it can be stated as L1 = L2 = (mutual inductance + leakage inductance) = M +

Lk. By substituting this in the above equation, the net equivalent inductance become

2

kL

(6)

So the net equivalent circuit become Fig. 13.

Fig. 13: Net equivalent circuit of case1

The leakage inductance, Lk is assumed to be zero. So +2E voltage across the load.

2.2.1.1 Case-2 (+E): In this case, the required output voltage level is +E. To achieve this there are two options. Option-1

with upper switches S1, S5 are turned ON along with lower switch S4 is turned ON. Option-2 with upper switch S1, S3 are

turned ON along with lower switch S6 is turned ON. The equivalent circuit becomes Fig. 14.




255

Now apply Thevenin theorem. Thevenin voltage is given by the Fig. 16. The inductors share the applied voltage

equally. So voltage across L2 is +E. Thevenin impedance is given by the Fig. 17. Inductors are parallel and opposing. So

the net inductance is given by

2

kL

(7)

Fig. 15: Load is removed from the equivalent circuit of case-2

Fig. 16: Thevenin voltage of case-2 Fig. 17: Thevenin impedance of case-2

Fig. 18: Thevenin equivalent circuit of case-2

The Thevenin circuit is given by the Fig. 8. The leakage inductance, Lk is assumed to be zero. So +E voltage

across the load.

2.2.1.1 Case-3 (-E): In this case, the required output voltage level is -E. To achieve this there are two options. Option-1

with upper switch S5 turned ON along with lower switches S2, S4 are turned ON. Option-2 with upper switch S3 turned

ON and lower switches S2, S6 are turned ON. The equivalent circuit becomes Fig. 19. By applying Thevenin theorem as

in the previous case, the Thevenin equivalent circuit is given as Fig. 20.



Fig.

The leakage inductance, Lk is assumed to be zero. So

2.2.1.1 Case-4 (-2E): In this case, the required output voltage level is 2E. To achieve this, upper switches S

turned ON along with the lower switch S


L

As in case-1, by considering the assumption it can be stated as L

inductance) = M + Lk. By substituting this in the above equation, the net equivalent inductance become

So the net equivalent circuit become Fig.

load as the load is connected from 2 to 1.

Fig

2.2.2 PLUSE WIDTH MODULATION

By proper modulation the existence of the DC component in the output voltage can be reduced. The DC

components in the output voltage result

the size and weight of the coupled inductor can be reduced.



256

Fig. 20: Thevenin Equivalent Circuit of Case-3

is assumed to be zero. So -E voltage across the load as the load is connected from 2 to 1.

In this case, the required output voltage level is 2E. To achieve this, upper switches S

the lower switch S2 is turned ON. The equivalent circuit becomes Fig. 2



MLL

MLL

221

2

21

++ (8)

1, by considering the assumption it can be stated as L1 = L2 = (mutual inductance + leakage

. By substituting this in the above equation, the net equivalent inductance become

2

kL

(9)

So the net equivalent circuit become Fig. 22 The leakage inductance, Lk is assumed to be zero. So

load as the load is connected from 2 to 1.

Fig. 22: Net Equivalent Circuit of Case4

PLUSE WIDTH MODULATION


components in the output voltage result in large current, which may result in the failure of the inverter. By modulation

the size and weight of the coupled inductor can be reduced.



E voltage across the load as the load is connected from 2 to 1.

In this case, the required output voltage level is 2E. To achieve this, upper switches S3, S5 are

21.

= (mutual inductance + leakage

. By substituting this in the above equation, the net equivalent inductance become

is assumed to be zero. So -2E voltage across the


in large current, which may result in the failure of the inverter. By modulation



257

3. SIMULATION RESULTS

To verify the validity of the paper, the circuit in this paper is simulated using MATLAB /Simulink tool. DC-DC

converter is combined with the inverter to provide a five level AC output voltage even if the input DC voltage varies.

Simulation is done with 18V DC and 12V DC inputs.

Fig. 23: Simulation of main circuit at 18V DC input

Fig. 24: Simulation result of main circuit at 18V DC

input

Fig. 25: Simulation result of main circuit at 12V DC

input

From above figures, it can be concluded that the the main circuit provided in the thesis provides a five level 70V

AC voltage even if the input DC voltage varies.

4. EXPERIMENTAL RESULTS

The inverter section and high step up converter section fabricated separately and are cascaded. Each section

consists of three parts; control circuit, drive circuit and power circuit. In the control circuit, to produce pulse width

modulated gate signal, PIC18F4550 is used. FAN7392 is used to drive the MOSFET. In the power circuit of converter,

polyester capacitor of 0.6mF is used as the pump capacitor. The switch used in the converter section is IRF830. The

coupled inductor wound over an “E” core with ten turns on one side and with thirty turns on other side is used. In

addition to this a small inductor is introduced to reduce the inrush current of the charge pump current loop. In the power

circuit of inverter, six numbers of IRF830 (MOSFET) is used to switch the coupled inductor. The coupled inductor is

wound over the ferrite “E” core with 22 SWG copper wire with mutual inductance of 1mH. The output is taken across

the load of 470 and 1.1mH.



258

The input given to the prototype is 12V DC. This input is boosted to 70V by the DC-DC converter. The inverter

converts the 70V DC to five level AC with a peak of 70V. The input is varied to 18V. With the help of feedback loop, the

inverter can maintain the same 70V in the out. This shows that the DC-DC converter can give a regulated output of 70V.

The inverter converts this regulated output into AC waveform. The Fig 26 and Fig 28 shows the input voltages given to

the prototype. The Fig 27 and Fig 29 shows the output voltages respectively. In both case, the output is around 70V.

Fig. 26: Hardware-18V DC input Fig. 27: Hardware-70V five level AC output when

18V DC is given as input

Fig. 28: Hardware-12V DC input Fig. 29: Hardware-70V Five level AC output when 12V

DC is given as input

In the Fig 27 displays a max voltage of 80V. By analysing the figure (by considering the voltage scale) it is clear

that the output voltage is constant at 70V. DSO displays the max voltage as 80V due to the ripple.

4. CONCLUSION

Simulated and fabricated a circuit for the regulated five level inverter. The input to this inverter is a low voltage

DC and a boosted, regulated AC is the output. This circuit can be used for converting the low voltages from PV panels or

from fuel cells to a boosted AC voltage, capable of using in micro grid system. It has the following features: By proper

switching technique, the no-load current drawn by the coupled inductor can be made negligible. This inverter can give a

five level AC output from a single source. This circuit is suitable for the PV system and fuel cell system if the input

voltage change in wide range. This circuit can deliver a premium power to the loads.



259

Fig. 30: Hardware- DC-DC converter section Fig. 31: Hardware- Inverter section

REFERENCES

[1] C. T. Pan, C. M. Lai, and M. C. Cheng, “A novel integrated single phase inverter with an auxiliary step-up

circuit for low-voltage alternative energy source application,” IEEE Trans. Power Electron., vol. 25, no. 9, pp.

2234 2241, Sep. 2010.

[2] C. T. Pan, C. M. Lai, and M. C. Cheng, “A novel high step-up ratio inverter for distributed energy resources

(DERs),” in Proc. IEEE Int. Power Electron. Conf., 2010, pp. 1433 1437

[3] F. Blaabjerg, Z. Chen, and S. B. Kjaer, “Power electronics as efficient interface in dispersed power generation

systems,” IEEE Trans. Power Electron., vol. 19, no. 5, pp. 11841194, Sep. 2004.

[4] D.M. Van de Sype, K.D. Gussem, B. Renders, A.P. Van den Bossche, and J.A. Melkebeek, “A Single switch

boost converter with a high conversion ratio”, in Proc. of IEEE APEC, Mar.2005, pp. 1581-1587.

[5] J.W. Baek, M.H. Ryoo, T.J. Kim, D.W. Yoo, and J.S. Kim, “High boost converter using voltage multiplier,” in

Proc. of IEEE IECON, Nov.2005, pp. 567 572.

[6] Y.P.B. Yeung, K.W.E. Cheng, S.L. Ho, K.K. Law, and D. Sutanto, “Unified analysis of switched-capacitor

resonant converters,” IEEE Trans. Ind. Electron., vol. 51, no. 4, Aug. 2004, pp. 864 873,.

[7] M.Malinowski, K. Gopakumar, J. Rodriguez, andM. A. Perez, “A survey on cascaded multilevel inverters,”

IEEE Trans. Ind. Electron., vol. 57, no. 7, pp. 2197 2206, Jul. 2010.

[8] J. Rodriguez, J.-S. Lai, and F. Z. Peng, “Multilevel inverters: A Survey of topologies, controls, and

applications,” IEEE Trans. Ind. Electron., vol. 49, no. 4, pp. 724 738, Aug. 2002.

[9] Zixin Li, Ping Wang, Yaohua Li, and Fanqiang Gao, “A Novel Single-Phase Five-Level Inverter With Coupled

Inductors,” IEEE Trans. Power Electron., vol. 27, no. 6,pp. 2716 2725, Jun. 2012.

[10] A. M. Knight, J. Ewanchuk, and J. C. Salmon, “Coupled three-phase inductors for interleaved inverter

switching,” IEEE Trans.Magn., vol. 44, no. 11, pp. 4199 4122, Nov. 2008.

[11] C. Chapelsky, J. Salmon, and A. M. Knight, “Design of the magnetic components for high-performance

multilevel half-bridge inverter legs,” IEEE Trans. Magn., vol. 45, no. 10, pp. 4785 4788, Oct. 2009.

[12] J. Salmon, A. Knight, and J. Ewanchuk, “Single phase multi-level PWM inverter topologies using coupled

inductors,” in Proc. IEEE Power Electron. Spec. Conf. (PESC), 2008, pp. 802 808.

[13] M. Ned, T. M. Undeland, and W. P. Robbins, Power Electronics: Converters, Applications and Design. Media

Enhanced Third Edition, Gurukripa Enterprises, Delhi, India:Wiley India edition, 2011.

[14] M.H Rashid, Power Electronics: Circuits, Devices and Applications. Third Edition, Gopson’s paper press Ltd.,

India:Pearson Education, Inc. , 2004.

[15] D. Floricau, E. Floricau, and G. Gateau, “New multilevel converters with coupled inductors: Properties and

control,” IEEE Trans. Ind. Elec-tron., vol. 58, no. 12, pp. 5344 5351, Jul. 2011.

[16] Y.-H. Liao and C.M. Lai, “Newly-constructed simplified single-phase multistring multilevel inverter topology

for distributed energy resources,” IEEE Trans. Power Electron., vol. 26, no. 9, pp. 2386 2392, Sep. 2011.

[17] W. Yu, C. Hutchens, J. S. Lai, J. Zhang, G. Lisi, A. Djabbari, G. Smith, and T. Hegarty, “High efficiency

converter with charge pump and coupled inductor for wide input photovoltaic AC module applications,” in Proc.

IEEE Energy Convers. Congr. Expo, 2009, pp. 3895 3900.

[18] Rajasekharachari K, K.Shalini, Kumar .K and S.R.Divya, “Advanced Five Level - Five Phase Cascaded

Multilevel Inverter With SVPWM Algorithm” International Journal of Electrical Engineering & Technology

(IJEET), Volume 4, Issue 4, 2012, pp. 144 - 158, ISSN Print : 0976-6545, ISSN Online: 0976-6553.



260

AUTHORS DETAILS

JOHN NINAN was born in Kerala. He received the B. Tech degree in Electrical and Electronics

Engineering from Mar Baselios Christian College of Engineering and Technology affiliated to

Mahatma Gandhi University, Kerala in 2007. He is currently pursuing his M. Tech Degree in

Power Electronics from Vidya Academy of Science and Technology, Thrissur, Kerala.

JASNA S.B was born in Kerala. She received M. Tech Degree in Applied Electronics. She is

currently Assistant Professor in the Department of Electrical and Electronics Engineering, Vidya

Academy of Science and Technology, Thrissur, India, where she has been a faculty member since

July 2007. She published a paper; An intelligent mobile robot navigation system using RF ID

technique with real time updation. Her interested areas are game theory, robotics etc

VIDHYA KG was born in Kerala. She received B.Tech degree in Electrical and Electronics

Engineering from Govt .Rajiv Gandhi Institute of Technology, Kottayam, Kerala in 2008.She

worked at MG UCE, Kerala from 2009-2012. She is currently pursuing her M. Tech Degree in

Power Electronics from Vidya Academy of Science and Technology, Thrissur, Kerala.