Analysis of DC-DC Sepic Converter with Different MPPT Technique

Ankur Kumar Gupta

, Yogesh K. Chauhan

, Rupendra Kumar Pachauri

, Deepa Sharma

, Rachna

Chaudhary

, Pankaj Kumar Gupta

R&D Department, SOCSA IIMT University, Meerut, UP, India

Electrical Department, KNIT Sultanpur, UP, India

Electrical and Electronics Engineering Department, University of Petroleum and Energy Studies, Dehradun, India

Dean Research, IIMT University, Meerut, UP, India

Computer science Department, IIMT University, MEERUT, UP, India

rachnacs1088@gmail.com, drpkg03@gmail.com

Keywords: DC- DC Converter, MPPT Converter, Constant Voltage Control, Perturb and Observation.

Abstract: In this research work the performance of the DC-DC converter has been evaluated with two techniques

Constant Voltage control (CVC) and Perturb and Observation (P&O) one by one. The power 456 Software

has been used for comparison purpose. The performance of the converter in case of P&O is found

satisfactory. The stress on the component is low in case of P&O. The circuit is able to run on the 80 percent

duty cycle. The DC-DC efficiency is 90.7 %. The efficiency of input filter is 89.9% has been recorded.

Which is higher than the CVC method. The overall performance is found satisfactory. The full irradiance of

1000 W/m2 has been assumed for this testing.

1 INTRODUCTION

Now a day’s low cost electricity is main requirement

of the industries as well as domestic use. Solar

energy promise for clean and green energy without

any noise. If the right direction has been tracked

then it will provide the maximum power to the load.

For this purpose the appropriate DC-DC converter

has been required with appropriate MPPT algorithm

(Kumar et al., 2015). There are so many converter in

the market which are used for this purpose. However

the proper tuning has been required to drive the

converter on maximum power point. There are so

many other factor which affects the performance of

the performance of the DC-DC converter (Mutoh

and Inoue, 2004). The behaviour of the DC-DC

converter is also affected by the type of the load.

The direct connection of the solar panel with the

battery not is preferable because the battery will get

damage and the other hand, the solar panel is unable

to drive on maximum power.

On the other hand, the different MPPT algorithm

are available which are use the DC-DC converter.

The main algorithms are perturb and observation,

constant voltage control, Incremental conductance,

constant current control. But all the algorithms

hastheir merits and demerits. The Perturb and

Observation is widely used due to its low

complexity. But the P&O algorithm unable to chase

the MPP under sudden change of irradiance (Gupta

et al., 2020; Gupta et al., 2018a; Pachauri and

Chauhan, 2015 ). However the Incremental

Conductance MPP technique provide the solution

for this problem and track the MPP even after the

sudden change in the irradiance (Gupta et al., 2016;

Liu et al., 2008a). On the other hand the Constant

Voltage Control method is the low cost solution to

achieve the MPP (Gupta et al., 2018b). But the

demerit of the CVC method is that it required to

update the open circuit voltage at particular interval

of time by disconnecting the load from the power

supply (Xiao and Dunford, 2004; Liu, 2008b). In

this research work, the performance of DC-DC

converter has been evaluated with the CVC

technique and Perturb Observation method.

However there are so many method to improve the

efficiency of DC-DC converter (Gupta et al., 2019).

Gupta, A., Chauhan, Y., Pachauri, R., Sharma, D., Chaudhary, R. and Gupta, P.

Analysis of DC-DC Sepic Converter with Different MPPT Technique.

DOI: 10.5220/0010562300003161

In Proceedings of the 3rd International Conference on Advanced Computing and Software Engineering (ICACSE 2021), pages 45-53

ISBN: 978-989-758-544-9

2 ANALYSIS OF THE DC-DC

CONVERTER WITH

DIFFERENT ALGORITHM

For the analysis of the converter the power 456

software has been used. The input of the converter is

represent by the Table. 1. The input of the DC-DC

converter has been provided by the solar panel. The

CVC method and P&O method has been loaded in

the converter one by one.

Table 1. Specification of the Input of DC-DC converter

The Table 1 provides the topology used for the

testing purpose. The control mode is the Current

mode which is shown in the Table 1.

Figure 1. Circuit Diagram of DC-DC Converter

The circuit diagram of DC-DC converter is shown in

Figure 1. The different type of control has provided

which has been discussed further. The comparator

has been used for current limit. The current limit

mode is required for battery charging purpose

because at the time of Bulk charging mode, the

battery try to consume the infinite current which

leads to permanent destroy the power supply. So, to

protect the power supply from high current demand,

the circuit operate on current limit mode. In this

mode the duly cycle is maximum. The maximum

current is 1.4 Amp for this operation. The minimum

current of current is 0.4 amp. On this current, the

circuit assume that the battery is full charge and do

not need further charging.

3 RESULTS AND DISCUSSION

The table 2 provide the different loses at the input

side when the DC-DC converter operates with P&O

technique. The equivalent series resistance is .085

Watt with the inductor conduction loss 0.136 Watt.

The power switch conduction loss is recorded as

0.259 Watt. Power Diode conduction loss is 0.739

Watt. The total conduction loss is 1.135 Watt and

the conduction efficiency is 94.66%.

Figure 2. Flow chart of P&O Method

The flow chart of P&O method is shown in figure 2.

First it will measure the Panel Current, Voltage and

compare it with the previous values and adjust the

duty cycle.

ICACSE 2021 - International Conference on Advanced Computing and Software Engineering

Table 2. Different type of losses in case of P&O Method

The table 3 provides the losses and efficiency when

the converter runs with P&O method.

Table 3. Converter loss and efficiency in case of P&O

Method

In this case the total conduction loss is 1.13

Watt. The stitching loss is 0.20 Watt. The core loss

is 0.04 watt. The total loss is 2.08 Watt. The DC-DC

efficiency is 90.7 %. The efficiency of input filter is

89.9% has been recorded.

Table 4. Characteristic of Power switch and Power Diode in case of P&O Method

Table.4 provide the details of Power switches and

power diode. The switch drop record 0.0 Volt.

However Switch R 0.080 Ω, Peak switch current

5.051 Amp, power dissipation 0.26 Watt, Peak

voltage stress 15 Volt, Nominal Voltage stress 14

Volt, per switch rms Current 1.80 Amp has been

recorded. On the other hand, the diode drop is

0.51Volt, diode ESR 0.003 Ω Peak diode current

0.000amp, Power dissipation across diode 0.738

Watt, Peak Voltage stress across diode 14.510 Volt,

Nominal Voltage stress 14.40 Volt, has been

recorded.

Table 5. Output component characteristics of component

in case of P&O Method

Table 5. Shows the value of equivalent series

resistance which is only 31.5 mΩ. The RMS current

is 1.66 Amp and the peak voltage is 14.5 Volt. The

dissipation is 0.09W has been recorded in case of

P&O method.

Analysis of DC-DC Sepic Converter with Different MPPT Technique

Figure. 3 Gain margin and Phase margin in case of P&O Method

The gain margin and phase margin are shown in

Figure 3. The Loop shows by red colour and the

power stage is shown by blue dotted line and

Compensator is shown by the

Black line. The loop is started by the 108 db. The

compensator starts 94 db and the power stage starts

from 18db. The Phase margin curve are also shown

in figure 2.

Table 6. Characteristic of PWM Controller and compensation values in case of P&O Method

Table 6.represent the condition of PWM

controller and compensation values when the

converter run on P&O. The max duty cycle is 80 %

in this condition.

ICACSE 2021 - International Conference on Advanced Computing and Software Engineering

Figure. 4 Input filter characteristics, impedance and attenuation in case of P&O Method

The input filter characteristics, impedance and

attenuation in case of P&O methods are shown in

figure 4. The ESR of inductor L1 is 20.09m Ω, the

ESR of capacitor C1 is 2.21 m Ω. The ESR of C2 is

12.05 Ω. The ESR of L2 20.09 m Ω and the ESR of

capacitor C3 is 12.05 m Ω.

Figure 5 Flow chart of CVC Algorithm

The flow chart of CVC method is shown in

figure 5. The V max is 80 percent of the Voc. The

value of Voc is update at after every 60 minutes. In

after every 60 min the circuit disconnect from the

load to measure the Voc. This is the major

Drawback of this technique.

Table 5. Different type of losses in case of CVC Method

The table 5 provide the different loses at the

input side when the DC-DC converter operates with

CVC technique. The equivalent series resistance is

0.114 Watt with the inductor conduction loss 0.180

Watt. The power switch conduction loss is recorded

as 1.531Watt. Power Diode conduction loss is 0.957

Watt. The total conduction loss is 1.531 Watt and

the conduction efficiency is 92.94%.

Analysis of DC-DC Sepic Converter with Different MPPT Technique

Table 7. Converter loss and efficiency in case of CVC

Method

The Table 7 provides the losses and efficiency when

the converter run with CVC method. In this case the

total conduction loss is 1.53 Watt. The switching

loss is 0.20 Watt. The core loss is 0.04 watt. The

total loss is 2.47 Watt. The DC-DC efficiency is

88.2 %. The efficiency of input filter is 76.0% has

been recorded.

Table 8. Characteristic of Power switch and Power Diode in case of CVC Method

Table. 8 provide the details of power switches

and power diode. The switch drop record 0.0 Volt.

However Switch R 0.080 Ω, Peak switch current

5.797 Amp, power dissipation 0.39 Watt, Peak

voltage stress 15 volt, Nominal Voltage stress 14

Volt, per switch rms Current 2.21 Amp has been

recorded. On the other hand, the diode drop is

0.51Volt, diode ESR 0.003 Ω Peak diode current

0.000 amp, Power dissipation across diode 0.958

Watt, Peak Voltage stress across diode 14.527 Volt,

Nominal Voltage stress 14.40 Volt, has been

recorded.

Table 9. Output component characteristics of component

in case of CVC Method

Table 9.Shows the value of equivalent series

resistance which is only 31.05 m Ω. The RMS

current is 1.92 Amp and the peak voltage is 14.5

Volt. The dissipation is 0.11W has been recorded in

case of CVC method.

ICACSE 2021 - International Conference on Advanced Computing and Software Engineering

Figure. 6 Gain margin and Phase margin in case of CVC Method

The gain margin and phase margin are shown in

Figure 6. The Loop shows by red colour and the

power stage is shown by blue dotted line and

Compensator is shown by the Black line. The loop is

started by the 100 db. The compensator starts 87 db

and the power stage starts from 17db. The Phase

margin curve are also shown in figure 4.

Table 10. Characteristic of PWM Controller and compensation values in case of CVC Method

Table 10. Represent the condition of PWM

controller and compensation values when the

converter run on CVC. The max duty cycle is 70 %

in this condition.

Analysis of DC-DC Sepic Converter with Different MPPT Technique

Figure. 7 Input filter characteristics, impedance and attenuation in case of CVC Method

The input filter characteristics, impedance and

attenuation in case of CVC methods are shown in

figure 7. The ESR of inductor L1 is 20.09m Ω, the

ESR of capacitor C1 is 2.21 m Ω. The ESR of C2 is

12.05 Ω. The ESR of L2 20.09 m Ω and the ESR of

capacitor C3 is 12.05 m Ω.

Table.11 Comparison of Different parameter of converter for P&O and CVC technique

S. No PARAMETER P&O CVC

1. Efficiency High LOW

2. Duty cycle 80% 70%

3. Diode stress Low High

4. Switching stress Low High

5. Gain margin GOOD BAD

6. Phase margin GOOD BAD

4 CONCLUSION

The different characteristics of the converter has

been recorded when drive it on the Different MPPT

one by one. The P&O provide the max duty cycle

and higher efficiency in comparison of CVC

method. P&O method offers minimum stress on the

components in comparison of P&O method. The

Overall performance of DC-DC converter is found

good in case of P&O. The gain margin and Phase

margin is also better in case of P&O method.

REFERENCES

Gupta, A., Chauhan, Y.K. and Pachauri, R.K. (2016). A

comparative investigation of maximum power point

tracking methods for solar PV system. Solar

energy, 136, 236-253.

ICACSE 2021 - International Conference on Advanced Computing and Software Engineering

Gupta, A.K., Chauhan, Y.K. & Maity, T. (2018a).

Experimental investigations and comparison of

various MPPT techniques for photovoltaic

system. Sādhanā, 43(8), 1-15.

Gupta, A.K., Chauhan, Y.K. and Maity, T. (2018b). A

new gamma scaling maximum power point tracking

method for solar photovoltaic panel Feeding energy

storage system. IETE Journal of Research, 1-21.

Gupta, A.K., Maity, T., Anandakumar, H. and Chauhan,

Y.K. (2020). An electromagnetic strategy to improve

the performance of PV panel under partial

shading. Computers & Electrical Engineering,

106896.

Gupta, V., Sharma, M., Pachauri, R.K. and Babu, K.D.

(2019). Comprehensive review on effect of dust on

solar photovoltaic system and mitigation

techniques. Solar Energy, 191, 596-622.

Kumar, P., Pachauri, R.K. and Chauhan, Y.K. (2015).

Duty ratio control schemes of DC-DC boost converter

integrated with solar PV system. In 2015 International

Conference on Energy Economics and Environment

(ICEEE), 1-6.

Liu, F., Duan, S., Liu, F., Liu, B. and Kang, Y. (2008a). A

variable step size INC MPPT method for PV

systems. IEEE Transactions on industrial

electronics, 55(7), 2622-2628.

Liu, F., Kang, Y., Zhang, Y. and Duan, S. (2008b).

Comparison of P&O and hill climbing MPPT methods

for grid-connected PV converter. In 2008 3rd IEEE

Conference on Industrial Electronics and

Applications, 804-807.

Mutoh, N., and Inoue, T. (2004). A controlling method for

charging photovoltaic generation power obtained by a

MPPT control method to series connected ultraelectric

double layer capacitors. In Conference 2004 IEEE

Industry Applications Conference, 39th IAS Annual

Meeting, 4, 2264-2271.

Pachauri, R.K. and Chauhan, Y.K. (2015). Comparative

Study of MPPT Methods for Solar PV Driven

Induction Motor Load. International Journal of

Computer Applications, 975, 8887.

Xiao, W. and Dunford, W.G., (2004). A modified adaptive

hill climbing MPPT method for photovoltaic power

systems. In 2004 IEEE 35th annual power electronics

specialists conference IEEE Cat. No. 04CH37551), 3,

1957-1963.

Analysis of DC-DC Sepic Converter with Different MPPT Technique