ABSTRACT:
An integration and operation of single phase
bidirectional inverter with two buck/boost maximum power point trackers (MMPTs)
is provided for dc distribution system. In a dc distribution system a
bidirectional inverter is required to control the power flow between dc bus and
ac grid, and to regulate the dc bus to the certain range of voltage. A droop
regulation mechanism is followed to reduce the capacitor size and to balance
the power flow between the dc bus and ac grid. The photovoltaic (PV) array
voltage can be vary from 0 to 600V, especially with
thin-film PV panels, the MPPT topology is formed with
buck and boost converters to operate at the dc-bus voltage around 380V,
reducing the voltage stress of its followed inverter. In this paper
the fuzzy logic technique is used to control the
bidirectional inverter for improve overall efficiency of the system and it is designed
by using MATLAB/SIMULINK software.
KEYWORDS:
1.Bi-directional inverter
2. buck/boost MPPTs
3. dc distribution system
SOFTWARE: MATLAB/SIMULINK
SIMULINK DIAGRAM:
Figure 1. Overall Simu link Model
EXPECTED SIMULATION RESULTS:
Figure 2. Grid Voltage
Figure 3. dc-bus voltage
Figure 4 Buck/Boost Output Waveform
Figure 5. Real and Reactive power
CONCLUSION:
A
single-phase bi-directional inverter with two buck/boost MPPTs has been
designed by using the MATLAB/SIMULINK.A buck/boost inverter can be used for
both the step-up and step-down process. The inverter controls the power flow
between dc bus and ac grid, and regulates the dc bus to a certain range of
voltages. Since the PV-array voltage can vary from 0 to 600 V, the MPPT
topology is formed with buck / boost converters to operate at the dc-bus
voltage around 380 V, reducing the voltage stress of its followed inverter.
Also the controller can on-line check the input configuration of the MPPTs,
equally distribute the PVarray output current to the two MPPTs in parallel
operation, and switch control laws to smooth out mode transition. In this the
fuzzy control technique has been used. Integration and operation of the overall
inverter system have been discussed in detail, which contributes to ac grid as
well as dc-distribution.
REFERENCES:
[1] Shih-Ming Chen, Student Member,
IEEE, Tsorng-Juu Liang, Senior Member, IEEE, Lung-Sheng Yang, and Jiann- Fuh
Chen, Member, IEEE: “A Boost Converter With Capacitor Multiplier and Coupled
Inductor for AC Module Applications” IEEE Transactions 2013.
[2] J.-M. Shen, H.-L. Jou, and J.-C.
Wu, “Novel transformer less grid connected power converter with
negativegrounding for photovoltaic generation system,” IEEE Transactions 2012.
[3] Tamás Kerekes, Member, IEEE, Remus
Teodorescu, Senior Member, IEEE, Pedro Rodríguez, Member, IEEE,Gerardo Vázquez,
Student Member, IEEE, and EmilianoAldabas, Member, IEEE: “A New High-Efficiency
Single- Phase Transformer less PV
Inverter Topology” IEEE Transactions 2011.
[4] Loc Nguyen Khanh, Student Member,
IEEE, Jae-Jin Seo, Yun-Seong Kim, and Dong-Jun Won, Member, IEEE: “Power-Management
Strategies for a Grid-Connected PV-FC Hybrid System” IEEE Transactions 2010.
[5] T.-F. Wu,K.-H.Sun, C.-L.Kuo, and
C.-H. Chang, “Predictive current controlled 5 kW single-phase bidirectional
inverter with wide inductance variation for DC micro grid applications,” IEEE
Transactions 2010.
