The document describes a hybrid green energy system that uses photovoltaic (PV) panels, wind turbines, and batteries to provide uninterrupted electrification. A new multiport, bidirectional converter is designed to integrate the PV and wind power sources. The PV panel generates 300W of power that is fed to the bidirectional converter. The wind power is harnessed using a transformer coupled to a dual-half bridge converter. Simulation results show the system can generate output voltage and current efficiently to justify its viability for powering homes continuously day and night.

1. Hybrid Green Energy Systems
for Uninterrupted Electrification
S. Lavanya Devi(&)
and S. Nagarajan
Department of EEE, Jerusalem College of Engineering, Chennai, India
lavanyadevi@jerusalemengg.ac.in, nagu_shola@gmail.com
Abstract. In this paper, a new multiport, hybrid green-fed DC-DC bidirectional
converter is designed and fed into the standalone system. This model is
developed and integrated to study the concept of generating systems. In this
model, a PV panel of 300 watts is designed and integrated to a bidirectional
converter with a battery backup to extract power, while the wind power is
harnessed with a transformer coupled a dual-half-bridge converter. The model
proposed is designed with a meritorious objective of sustainable, cost-effective,
less component count reduced losses, and good efficiency with a good relia-
bility. The system works day and night to produce output with good efficiency.
The simulation results are obtained using MATLAB software 2014a, and hence,
the performance is analyzed.
Keywords: Bidirectional converter (BDC) Photovoltaic (PV) Wind Dual
half bridge converter
1 Introduction
Due to the fast depletion of fossil fuels, we are in a situation to extract power from the
renewable energy sources. Sun and wind are the chief sources of energy for planet
Earth, which are supportable and unlimited. Fortunately, our India is highly enriched
with solar insolation levels, and wind has its own impact throughout the year, making it
wise to harvest the energy from them. Among the many renewable energy sources
available, solar photovoltaic and wind energy have the highest potential to generate
green power clean and for all our future needs. Calculating of RES varies according to
availability, season, and their considerable instability [2]. Hence, this proposed system
is introduced and used intensively. This topology allows energy source diversification.
The buildings using this concept are transformed to independent energy system.
• Usage of RES in a useful way
• High efficiency
• Prolonged existence time
• Low cost and reliability
• Good power quality
• Low maintenance
• Low acoustic noises and losses
• Enhancement in battery charging efficiency
© Springer Nature Singapore Pte Ltd. 2020
N. Goel et al. (eds.), Modelling, Simulation and Intelligent Computing,
Lecture Notes in Electrical Engineering 659,
https://doi.org/10.1007/978-981-15-4775-1_22

2. The proposed system shown in Fig. 1 is the complementary behavior of solar
insolation and wind velocity with battery led to its usage in household applications.
This hybrid system works in either standalone mode or grid-connected mode [3]. This
use of multi-input converter for hybrid power system is attracting increasingly its
attention because of its numerous advantages with centralized control.
2 Converter Configuration
The basic circuit diagram of a bidirectional DC-DC converter is shown in Fig. 2. It
consists of two switches. It acts as a boost converter in a forward direction (mode 1)
and acts as a back converter in the reverse direction (mode 2). The complete analysis
and design of a bidirectional DC-DC converter are explained. The converter is
designed using these formulas.
Fig. 1 Proposed system using green energy systems
Fig. 2 Bidirectional DC-DC converter
202 S. Lavanya Devi and S. Nagarajan

3. Io ¼
Po
Vo
R ¼
Vo
Io
DIo ¼ 0:2
AVo ¼ 1% of Vo
L ¼
D 1 D
ð Þ2
:Vo
2:fs:AIo
D ¼ 1
Vin
Vout
Cout ¼
D:Io
f DVo
Thus, the values of inductors, capacitors, and gate pulses are designed to get the
good efficient output.
3 Proposed Topology for Standalone Systems
The proposed converter consists of PV-fed DC-DC converter and wind with a
transformer-coupled bidirectional converters fused with a single-phase inverter con-
nected to a RL load. This proposed system has reduced power-converting stages with
less component count and high efficiency. The system is described in Fig. 3.
There exists two DC links on both sides of high-frequency transformers. The
control of voltage on both sides is facilitated by these two DC links. Thus, simple
control strategy is followed. The boosting capacity is incorporated by pv coupled with a
converter and wind with a DC-DC converter [1]. This transformer provides the
Fig. 3 Schematic diagram of the proposed green energy system
Hybrid Green Energy Systems for Uninterrupted Electrification 203

4. isolation to load from sources and battery. The extraordinary feature of the converter is
maximum power tracking using PO algorithm of both pv and wind along with the
charging and discharging control of the battery. The solar- and series-connected bat-
teries are controlled by MPPT algorithm, and pulses are generated to control the
switches T1 and T2 as shown in Fig. 4. When the voltage level of the pv is greater than
the battery, the battery is charged and in the absence of pv, battery comes into role.
That is, when the voltage level of the battery is high when compared to solar, inductor
current reverses. The battery discharges. Thus, the wind fed to DC-DC converters is
coupled with BDC fed by PV through dc link connected to the high frequency
transformer then to the inverter to the load for domestic applications.
4 Simulation Results
The simulation studies are done with MATLAB 2014a platform [5]. The results
obtained for the proposed topology using green energy are fed to a bidirectional
converter to a standalone system. The PV panel and wind turbine are designed to
generate a voltage of 300 V when fed to a bidirectional converter to provide a smooth
DC link when connected to a multiport transformer. The simulation results obtained
from the PV panel are shown below in Figs. 5, 6, and 7.
Fig. 4 Circuit diagram of the proposed green energy system fed to bidirectional converter
Fig. 5 Output voltage from the PV source
204 S. Lavanya Devi and S. Nagarajan

5. Thus, the output voltage from the converter fed with PV source is obtained as
300 V shown below in Fig. 8.
The simulated results of wind source are designed to effectively integrate with
bidirectional converter as shown below in Figs. 9, 10, and 11.
The output voltage from the bidirectional converter fed with wind source is
obtained as 300 V in order to have a smooth coupling of the DC link at the primary
side of the transformer shown below in Fig. 12.
Fig. 6 Output current from the PV source
Fig. 7 Output power from the PV source
Fig. 8 Output voltage from the bidirectional converter fed with PV source
Hybrid Green Energy Systems for Uninterrupted Electrification 205

6. The pulses generated are shown below in Fig. 13 to control the switches of the
single-phase inverter fed to a RL load.
Thus, the output voltage and current are obtained from the proposed system to
justify the viability as shown in Figs. 14 and 15, respectively.
Fig. 9 Output voltage from the wind source
Fig. 10 Output current from the wind source
Fig. 11 Output power from wind source
206 S. Lavanya Devi and S. Nagarajan

7. Fig. 12 Output voltage from the bidirectional converter fed with wind source
Fig. 13 Pulses generated to the switches of inverter
Fig. 14 Output voltage of the proposed green energy systems fed with bidirectional converter to
the standalone systems
Fig. 15 Output current of the proposed green energy systems fed with bidirectional converter to
the standalone systems
Hybrid Green Energy Systems for Uninterrupted Electrification 207

8. 5 Conclusion
A power emigration scheme using a standalone hybrid PV, wind, and battery for
domiciliary applications is proposed. The planned green energy hybrid system provides
efficient integration of PV and wind with battery backup to extract maximum power. It
is realized by a new multiport transformer-coupled bidirectional converter followed by
a full-bridge converter with an efficient control scheme, which utilizes PV, wind power,
and battery capacity for the application. Detailed simulation studies are carried out to
justify the viability of the scheme. Thus, in future the experimental studies can be
carried out and also the plan is to be carried out in grid-connected mode for better
results in future. Thus, the proposed model is highly efficient to provide uninterrupted
electrification all around the clock to ensure high reliability, and the values are
ascertained.
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208 S. Lavanya Devi and S. Nagarajan