Microinverter

1. SINGLE PHASE SOFT SWITCHING
GRID TIED MICROINVERTER FOR
PHOTOVOLTAIC APPLICATIONS
Presented by,
Vijisha.E.V
S3, M.Tech
VAS15EEPE08
Guide:
Dr. Nimal Madhu M.
Associate Professor
VAST
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2. INTRODUCTION
• Solar photovoltaic energy is most common among the
renewable power generation systems.
• Hence, grid integration of this technology is crucial for
effective utilization of this technique.
• This can be facilitated by means of a DC-DC-AC
converter
• Microinverter offers high efficiency and power
capacity than other topologies.
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3. • PV inverter topology with galvanic isolation is
preferred for the microinverter.
• Proposed microinverter has the structure to minimize
power losses.
• Soft switching technique should be employed to
improve the efficiency in the proposed inverter.
• Maximum power point tracking(MPPT) is used to
extract maximum power from the PV system.
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INTRODUCTION

4. OBJECTIVE
• Development of microinverter with soft switching
operation for harnessing solar power and delivering it
to the grid.
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5. 5
PROPOSED SYSTEM

6. Operation States & Theoretical Waveforms of DC-DC Stage
MODE 1[t0, t1]
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7. MODE 2[t1, t2]
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8. MODE 3[t2, t3]
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9. MODE 4[t3, t4]
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10. MODE 5[t4, t5]
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11. MODE 6 [t5, t6]
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12. OPERATION STATES OF PROPOSED
INVERTER
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 In The Positive Grid Voltage

13. 13
 In the Negative Grid Voltage

14. CIRCUIT SPECIFICATIONS
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SL
NO
PARAMETERS SYMBOLS VALUE
1 PV Voltage Vpv 45-75V
2 Output Voltage (dc-dc stage) Vd 350V
3 Grid Voltage Vg 220Vrms
4 Switching Frequency(dc-dc
stage) fs,dc
50kHz
4 Inverter Switching frequency fs 16kHz
5 Clamp Capacitor Cc 2.2 μF
6 Resonant Capacitor Cr 2.4 μF
7 Turn Ratio N1:N2 9:38
8 Magnetizing Inductance Lm 20 μH
9 Leakage Inductance L1k 2.6H
10 Inverter Filter Inductance Lp, Ln 15mH

15. SIMULATION BLOCK OF DC-DC STAGE
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16. SIMULATION RESULTS
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 Output Voltage Waveform

17. Trigger Signals for Switches S1& S2
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18. Voltage & Current Waveforms of the Switch S1
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19. Voltage & Current Waveforms of the Switch S2
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20. Voltage & Current Waveform of Diode Dr1
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21. Voltage & Current waveform of the Diode Dr2
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22. SIMULATION BLOCK OF INVERTER STAGE
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23. Trigger Signals for Switches
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24. SUMMARY
• Proposed DC-DC Stage is simulated using
Simulink(MATLAB)
• Soft switching operation for all switches are
evaluated
• Operating states of DC-DC stage is analysed
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25. FUTURE WORK
• Develop control circuitry to synchronize the output
voltage to the grid with the help of PLL
• Implement maximum power point tracking(MPPT) to
tap maximum solar power with dc-dc converter
• Fabricate and test the circuit
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26. REFERENCES
[1] N. Sukesh, M. Pahlevaninezhad, and P. K. Jain, “Analysis and
implementation of a single-stage flyback PV microinverter
with soft switching,” IEEE Trans. Ind. Electron., vol. 61, no. 4,
pp. 1819–1833, Apr. 2014.
[2] Y. Xue, L.Chang, S.B. Kjær, J. Bordonau, and T. Shimizu,
“Topologies of single-phase inverters for small distributed
power generators: An overview,”IEEE Trans.Power Electron.,
vol. 19, no. 5, pp. 1305–1314, Sep. 2004.
[3] R. W. Erickson and A. P. Rogers,“A microinverter for building-
integrated photovoltaics,” in Proc. IEEE Appl. Power Electron.
Conf. Expo., Feb. 2009, pp. 911–917.
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27. [4] W. Y. Choi, “High-efficiency DC-DC converter with fast
dynamic response for low-voltage photovoltaic sources,” IEEE
Trans. Power Electron., vol. 28, no.2, pp.706–716,Feb. 2013.
[5] D. Meneses et al., “Single-stage grid-connected forward
microinverter with constant off-time boundary mode control,”
in Proc. IEEE Appl. Power Electron. Conf. Expo., Feb. 2012,
pp. 568–574.
[6] T. Kerekes, R. Teodorescu, P. Rodríguez, G. Vázquez, and E.
Aldabas, “A new high-efficiency single-phase transformerless
PV inverter topology,” IEEE Trans. Ind. Electron., vol. 58, no.
1, pp. 184–191, Jan. 2011.
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