ABSTRACT:
In this paper, a control strategy for power flow management
of a grid-connected hybrid photovoltaic (PV)–wind battery- based system with an
efficient multi-input transformer coupled bidirectional dc–dc converter is
presented. The proposed system aims to satisfy the load demand, manage the
power flow from different sources, inject the surplus power into the grid, and
charge the battery from the grid as and when required. A transformer-coupled
boost half-bridge converter is used to harness power from wind, while a
bidirectional buck– boost converter is used to harness power from PV along with
battery charging/discharging control. A single-phase full-bridge bidirectional
converter is used for feeding ac loads and interaction with the grid. The
proposed converter architecture has reduced number of power conversion stages
with less component count and reduced losses compared with existing
grid-connected hybrid systems. This improves the efficiency and the reliability
of the system. Simulation results obtained using MATLAB/Simulink show the
performance of the proposed control strategy for power flow management under
various modes of operation. The effectiveness of the topology and the efficacy
of the proposed control strategy are validated through detailed experimental studies
to demonstrate the capability of the system operation in different modes.
KEYWORDS:
1.
Battery charge
control
2.
Bidirectional
buck–boost converter
3.
Full-bridge
bidirectional converter
4.
Hybrid system
5.
Maximum
power-point tracking
6.
Solar
photovoltaic (PV)
7.
Transformer-coupled
boost dual-half-bridge bidirectional converter
8. Wind energy
SOFTWARE: MATLAB/SIMULINK
BLOCK DIAGRAM:
Fig.
1. Grid-connected hybrid PV–wind-battery-based system for household
applications.
CIRCUIT DIAGRAM
Fig
2. Proposed converter configuration.
EXPECTED SIMULATION RESULTS:
Fig.
3. Steady-state operation in the MPPT mode.
Fig.
4. Response of the system for changes in an insolation level of source-1
(PV
source) during operation in the MPPT mode.
Fig.
5. Response of the system for changes in wind speed level of source-2
(wind
source) during operation in the MPPT mode.
Fig.
6. Response of the system in the absence of source-1 (PV source),
while
source-2 continues to operate at MPPT.
Fig.
7. Response of the system in the absence of source-2 (wind source),
while
source-1 continues to operate at MPPT.
Fig.
8. Response of the system in the absence of both the sources and
charging
the battery from the grid.
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. 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.
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