**ABSTRACT:**** **

This paper being an adaptive proportional resonant (PR) controller for single phase grid connected inverter that adapts its control parameters to grid impedance change. Forth order band bass filter is method and then merge with the adaptive system for on-line detection of any variations in the resonance frequency. The estimated frequency is then prepared by statistical signal processing operation to identify the variations in the grid impedance. For the on–line tuning of the PR parameters, a look-up table technique is utilized and its parameters are linked with the measure impedance values. Simulation results based on MATLAB environment clearly verify the effectiveness of the proposed control scheme for 2 kW grid connected inverter system.

** **

**KEYWORDS:**

- Adaptive Proportional Resonant Controller
- Grid Impedance Estimation
- LCL Filter
- Look-up Table

** ****SOFTWARE:** MATLAB/SIMULINK

** ****BLOCK DIAGRAM:**

** **

Fig. 1. Block diagram of the proposed adaptive PR controller.

** ****EXPECTED SIMULATION RESULTS:**

** **

Fig. 2. Simulation result of emulated grid voltage.

Fig.3. FFT analysis of grid current. (a) APR controller. (b).PR controller.

Fig. 4. Online adaptation of the APR control parameters.

Fig. 5. Grid voltage and current waveforms under changeable grid

impedance with the proposed control strategy.

** ****CONCLUSION:**

** **A new control strategy based on an adaptive proportional resonant (APR) controller has been grown and successfully proved on a simulated 2 kW single phase grid tide PV inverter. A fourth order Sallen-Key band pass filter tailored to the system to taking the harmonic components around the resonant frequency has been execute. data signal processing metthod was employed in order to provide the controller with signals compare to the variable grid impedance. A large low level of current total harmonic distortion (THD) is reach in comparison with conventional PR controller and submission with IEEE929-Standard has been show.

**REFERENCES:**

[1] S. Kouro, J. I. Leon, D. Vinnikov, and L. G. Franquelo, “Grid-Connected Photovoltaic Systems: An Overview of Recent Research and Emerging PV Converter Technology,” *IEEE Industrial Electronics Magazine, *vol. 9, pp. 47-61, 2015.

[2] “IEEE Recommended Practice for Utility Interface of Photovoltaic (PV) Systems,” in *IEEE Std 929-2000*, ed, 2000.

[3] “IEEE Draft Application Guide for IEEE Standard 1547, Interconnecting Distributed Resources With Electric Power Systems,” in *IEEE Unapproved Draft Std P1547.2/D11, Sept 2008*, ed, 2008, p. 1.

[4] H. M. El-Deeb, A. Elserougi, A. S. Abdel-Khalik, S. Ahmed, and A. M. Massoud, “An adaptive PR controller for inverter-based distribution generation with active damped LCL filter,” in *2013 7th IEEE GCC Conference and Exhibition (GCC)*, 2013, pp. 462-467.

[5] W. L. Chen and J. S. Lin, “One-Dimensional Optimization for Proportional-Resonant Controller Design Against the Change in Source Impedance and Solar Irradiation in PV Systems,” *IEEE Transactions on Industrial Electronics, *vol. 61, pp. 1845-1854, 2014.