RENEWABLE ENERGY BASED MULTI INPUT DC -DC CONVERTER · control techniques for a stand -alone hybrid...

RENEWABLE ENERGY BASED MULTI INPUT

DC-DC CONVERTER 1T Alex Stanley Raja, 2R Senthil Kumar, 3K V Santhosh Kumar

1Assistant Professor, Department of EEE, Bannari Amman Institute of Technology, Sathyamangalam,

Tamilnadu, India.

2 Professor, Department of EEE, Bannari Amman Institute of Technology, Sathyamangalam, Tamilnadu,

India

3 Assistant Professor, Department of EEE, Bannari Amman Institute of Technology, Sathyamangalam,

Tamilnadu,India

[email protected], [email protected], [email protected]

Abstract - There has been an increase in demand for clean and sustainable energy sources, and solar energy is

currently considered to be one of the most valuable and abundant yet low -maintenance clean sustainable energy

source. Photovoltaic solar energy systems require DC-DC converter in order to regulate and control the varying output

of the solar panel. This paper suggests a converter design that will ensure high performance and cos t efficiency. The

converter has been simulated in MATLAB and the hardware was done by choosing the design values appropriately.

This design aims to have lower losses for higher switching frequencies, and maximize the added advantages of the

proposed converter, such as low ripple, high efficiency and low electrical stress on the components.

Keywords - Solar; Renewable; Buck -Boost; DC/DC Converter; MATLAB.

I. INTRODUCTION

Rapid depletion of fossil fuel reserves, ever increasing energy demand and concerns over climate change

motivate power generation from renewable energy sources. Solar photovoltaic (PV) and wind have emerged as popular

energy sources due to their ecofriendly nature and cost effectiveness. However, these sources are intermittent in nature.

Hence, it is a challenge to supply stable and continuous power using these sources. This can be addressed by efficiently

integrating with energy storage elements. The interesting complementary behavior of solar insolation and wind velocity

pattern coupled with the above-mentioned advantages has led to the research on their integration resulting in the hybrid

PV– wind systems. For achieving the integration of multiple renewable sources, the traditional approach involves using

dedicated single-input converters one for each source, which are connected to a common dc-bus [1]. However, these

International Journal of Pure and Applied MathematicsVolume 119 No. 18 2018, 2251-2258ISSN: 1314-3395 (on-line version)url: http://www.acadpubl.eu/hub/Special Issue http://www.acadpubl.eu/hub/

2251

converters are not effectively utilized, due the intermittent nature of the renewable sources. In addition, there are

multiple power conversion stages which reduce the efficiency of the system. A significant amount of the literature

exists on the integration of solar and wind energy, as a hybrid energy generation system mainly focuses on its sizing

and optimization.

In the sizing of generators in a hybrid system is investigated. In this system, the sources and storage are

interfaced at the dc-link through their dedicated converters. Other contributions are made on their modeling aspects and

control techniques for a stand-alone hybrid energy system. Dynamic performance of a stand-alone hybrid PV–wind

system with battery storage is analyzed. [2],[3]. In a passivity/sliding mode control is presented which controls the

operation of wind energy system to complement the solar energy generating system. Not many attempts are made to

optimize the circuit con-figuration of these systems that could reduce the cost and increase the efficiency and reliability.

In integrated converters for PV and wind energy systems are presented. PV–wind hybrid system, proposed has a simple

power topology, but it is suitable for stand-alone applications.

II. INTERLEAVED DC-DC BOOST CONVERTER

A two-phase interleaved boost converter is usually employed in high input -current and high input-to-output

voltage conversion applications. The circuit diagrams of the two phase interleaved boost converter with uncoupled,

directly coupled is shown.

Fig.1 Interleaved dc-dc boost converter

There are two modes of operation in two phase interleaved boost converter for renewable energy applications

such as photovoltaic module, fuel cell [4].

International Journal of Pure and Applied Mathematics Special Issue

2252

Mode 1 Operation: (0 ≤ t < t1):

At t =0, the gate pulse is given to the switch ‗S1‗ of the first phase. Then the switch ‗S1‗ is turned on, the

current across the inductor L1 rises linearly. At the same time, the switch ‗S2‗ in the second phase is turned off and the

energy stored in the inductor L2 is transferred to the load through the output diode D2. In this time interval, the diode

D1 in the first phase is in reverse bias condition. At time t0, S1 is closed. The current in the inductor L1 starts to rise

while L2 continues to discharge. The rate of change of iL2 is approximately given by,

Mode 2 Operation: (t1 ≤ t < t2):

At t = t1, the gate pulse is given to the switch ‗S2‗ of the first phase. Then the switch ‗S2‗ is turned on, the

current across the inductor L2 rises linearly. At the same time, the switch ‗S1‗ in the first phase is turned off and the

energy stored in the inductor L1 is transferred to the load through the output diode D1. In this time interva l, the diode

D2 in the second phase is in reverse bias condition.

At time t1, S2 is closed. The current in the inductor L2 starts to rise while L1 continues to discharge. The rate of change

to rise of IL1is approximately obtained.

III. PRO POSED METHO DO LO GY

Fig.2 Block diagram of proposed system


2253

An integrated four-port topology based on hybrid PV–wind system is proposed. However, despite simple

topology, the control scheme used is complex. In feed the dc loads, a low capacity multiport converter for a hybrid

system is presented. Hybrid PV–wind-based generation of electricity and its interface with the power grid are the

important research areas have proposed a multi-input hybrid PV–wind power generation system which has a boost-

fused multi-input dc–dc converter [5]. This system is mainly focused on improving the dc-link voltage regulation. In the

interleaved boost converter topology proposed in the outputs of a PV array and wind generators are fed to a boost

converter. The use of multi-input converter for hybrid power systems is attracting increasing attention because of

reduced component count, enhanced power density, compactness, and control.

Due to these advantages, many topologies are proposed, and they can be classified into three groups, namely,

nonisolated, fully isolated, and partially isolated multiport topologies.[6] All the power ports in nonisolated multiport

topologies share a common ground. To derive the multiport dc–dc converters, a series or parallel configuration is

employed in the input side.

IV. SIMULATIO N AND RESULTS

Fig.3 PV-WIND Coupled DC/DC Converter

Fig 3 shows the simulation model of proposed system. The input to the converter is given from the sources as

wind and solar. The output is taken out from interleaved dc –dc boost converter. The simulations results of the

converter under different cases are given below,

The output from the solar panel is given to the converter.


2254

Fig. 4 Input to the Converter

As the wind system gives AC voltage, it is converted into DC voltage by rectifier.

Fig. 5 Output from Rectifier

The output from the converter when wind block output is given as input

Fig. 6 Converter output fed by wind


2255

In this case output of the overall project is shown. When all sources (solar, wind, battery) are in closed state ,

the below output is obtained.

Fig.7 Overall output with both wind and PV input

The following table below shows the input and the output of the converter proposed by the project.

Table 1. Comparison of the input and output of the converter

The total output obtained from the system when both the sources are used is 275 V.

V. CONCLUSION

A grid-connected hybrid PV–wind-battery-based power evacuation scheme for household application is

proposed. The proposed hybrid system provides an elegant integration of PV and wind source to extract maximum

energy from the two sources. It is realized by a novel multi-input transformer-coupled bidirectional dc–dc converter

followed by a conventional full-bridge inverter. A versatile control strategy which achieves a better utilization of PV,

wind power, battery capacities without effecting life of battery, and power flow management in a grid-connected hybrid

PV–wind-battery-based system feeding ac loads is presented. Detailed simulation studies are carried out to ascertain the

viability of the scheme.

Solar Wind

Input of the

converter 150 V

Generator

output=140V

rectified

output=135V

Output of the

converter 290V 290V


2256

The experimental results obtained are in close agreement with simulations and are supportive in demonstrating the

capability of the system to operate either in grid feeding or in stand-alone modes. The proposed configuration is capable

of supplying uninterruptible power to ac loads, and ensures the evacuation of surplus PV and wind power into the grid.

REFERENCES

[1] Grid-Connected PV-Wind-Battery-Based Multi-Input Transformer-Coupled Bidirectional DC-DC Converter by B.

Mangu, Member, IEEE, S. Akshatha, Student Member, IEEE, D. Suryanarayana, Member, IEEE, and B. G. Fernandes,

Member, IEEE.

[2] H. Wu, K. Sun, S. Ding, and Y. Xing, ―Topology derivation of nonisolated three -port DC–DC converters from

DIC and DOC,‖ IEEE Trans. Power Electron., vol. 28, no. 7, pp. 3297–3307, Jul. 2013.

[3] F. Valenciaga and P. F. Puleston, ―Supervisor control for a stand -alone hybrid generation system using wind and

photovoltaic energy,‖ IEEE Trans. Energy Convers., vol. 20, no. 2, pp. 398-405, Jun. 2005.

[4] M. Dali, J. Belhadj, and X. Roboam, ―Hybrid solar–wind system with battery storage operating in grid-connected

and standalone mode: Control and energy management—Experimental investigation,‖ Energy, vol. 35, no. 6, pp.

2587–2595, Jun. 2010.

[5]Balamurugan.E, jagadeesan.A, ―Geographic Routing Resilient To Location Errors‖, International Journal Of Innovations In Scientific And Engineering Research Vol 5, no3, PP21-

26,MAR 2018.

[6] W. D. Kellogg, M. H. Nehrir, G. Venkataramanan, and V. Gerez, ―Gen -eration unit sizing and cost analysis for

stand-alone wind, photovoltaic, and hybrid wind/PV systems,‖ IEEE Trans. Energy Convers., vol. 13, no. 1, pp. 70–

75, Mar. 1998.


2257

RENEWABLE ENERGY BASED MULTI INPUT DC -DC CONVERTER · control techniques for a stand -alone hybrid...

Documents

Transcript of RENEWABLE ENERGY BASED MULTI INPUT DC -DC CONVERTER · control techniques for a stand -alone hybrid...