Grid Interactive PV System with Harmonic and Reactive Power Compensation Features using a Novel Fuzzy Logic Based MPPT

ABSTRACT:

Photovoltaic (PV) cell characteristics are highly nonlinear that gives single Maximum Power Point (MPP) on P-V curve under uniform insolation condition. The characteristics and hence MPP point changes with the variation in insolation and temperature. In order to extract a maximum power from PV array, a fuzzy based MPP tracking algorithm is proposed. The algorithm accepts single input that is slope of P-V curve and generates the duty ratio as an output that operates the boost converter to track MPP. The algorithm gives faster convergence by applying variable step in duty ratio and gives accurate MPP. The two stage grid interactive PV system described in this paper supplies active power as well as provides harmonic and reactive power compensation. This additional feature increases the effective utilization of PV inverter and increases the overall efficiency of the system. The simulation results validate the performance and stability of the grid interactive PV system using the proposed algorithm for active current injection as well as harmonics and reactive power compensation.

KEYWORDS:

1.     Photovoltaic system

2.     Maximum power point tracking

3.     Fuzzy logic controller

4.     Harmonic elimination

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

EXPECTED SIMULATION RESULTS:

 CONCLUSION:

In this paper, multi functional grid interactive PV system is presented using a novel fuzzy logic based MPPT. The proposed MPPT controller is able to track the MPP accurately under uniformly varying as well as rapidly changing insolation and gives faster convergence as a variable step size in duty ratio is applied inherently by the algorithm. The proposed fuzzy controller maintains the dc link voltage within the limit for injecting the power into the grid. Apart from injecting active power during day time, the PV inverter also compensates the harmonics and reactive power during day time as well as at night. The current drawn from the grid is sinusoidal and the total harmonic distortion is well below the specified limit in the IEEE-519 standard. The simulation results validate the performance of grid interactive PV system for both active power injection as well as shunt active power filter functionality to mitigate the power quality issues thus increases the utilization factor of the system.

REFERENCES:

 [1] T. Esram and P. Chapman, “Comparision of photovoltaic array maximum power point tracking techniques”, IEEE Trans. on Energy Conversion, vol. 22, No. 2, June 2007.

[2] S. Jain and V. Agarwal , “Comparison of the performance of maximum power point tracking schemes applied to single-stage grid-connected photovoltaic systems”, IET Electr. Power Appl., vol. 1, no. 756(5), pp. 753-762, September 2007.

[3] P. Takun, S. Kaitwanidvilai and C. Jettanasen, “Maximum Power Point Tracking using Fuzzy Logic Control for Photovoltaic Systems”, International conference of engineers and computer scientists (IMECS), Vol.-II, pp. 986-990, March-2011.