A Direct Maximum Power Point Tracking Method for Single-Phase Grid Connected PV Inverters

ABSTRACT:

A direct maximum power point tracking (MPPT) strategy for PV frameworks has been proposed in this work. This strategy unravels two of the primary disadvantages of the Perturb and Observe (P&O) MPPT, in particular: I) the tradeoff between the speed and the motions in relentless state, ii) the poor viability in unique conditions, particularly in low irradiance when the estimation of signs turns out to be progressively touchy to clamor. The proposed MPPT is intended for single-stage single-arrange matrix associated PV inverters and depends on evaluating the swell of the quick PV power and voltage, utilizing a second-arrange summed up integrator-based quadrature flag generator (SOGI-QSG). We broke down the worldwide soundness of the shut circle control framework and approved the proposed calculation through reenactment and analyses on an inverter test stage as per the EN 50530 standard. The test results affirm the execution of the proposed technique as far as both speed and following effectiveness.

 

 BLOCK DIAGRAM:

Fig. 1. System configuration of single-stage single-phase grid-connected PV system.

 

EXPECTED SIMULATION RESULTS:

 

Fig. 2. Experimental PV voltage waveforms after startup showing the convergence to MPP with different 𝐾 values.

 

Fig. 3. Start waveforms comparison for DC link voltage.

Fig. 4. The output PV power under trapezoidal irradiance profile.

Fig. 5. DC link voltage under trapezoidal irradiance profile

Fig. 6. Instantanous efficiency under trapezoidal irradiance profile.

Fig. 7. Experimental start waveforms of PV power for both methods.

Fig. 8. Experimental start waveforms comparison of DC link voltage.

Fig. 9. Experimental results of PV power under trapezoidal irradiance profile.

Fig. 10. Experimental results for DC link voltage under trapezoidal irradiance profile.

Fig. 11. Efficiency under static irradiance for both methods.

Fig. 12. PV power for P&O under dynamic irradiance profile according to EN 50530.

Fig. 13. PV power for the proposed method under dynamic irradiance profile according to EN 50503.

Fig. 14. Efficiency comparison for the both methods from low-to-medium irradiance

Fig. 15. Efficiency comparison for the both methods from medium-to-high irradiance.

 

CONCLUSION:

This paper has depicted the structure of a successful controller for direct achieving the most extreme power point for a solitary stage single-stage lattice associated PV inverter. The proposed technique has been structured dependent on the steadiness examination utilizing the Lyapunov quadratic capacity that is framed from the variety of vitality put away in the DC connect capacitor. From the reproductions and trial results on a propelled test stage and as indicated by the EN 50530 standard, it was affirmed that the proposed technique accomplishes high productivity in both static and dynamic conditions. Moreover, the proposed strategy is quick to achieve the MPP.

 

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