Harmonic Reduction in grid-connected PV system with double tuned filter
This article discusses a MATLAB-based approach to modeling and simulating a grid-connected photovoltaic (PV) system. The system includes a PV panel, boost converter, inverter, grid, nonlinear load, and a double-tuned filter. The focus is on the control strategy implemented for the boost converter using the Maximum Power Point Tracking (MPPT) algorithm and the integration of a double-tuned filter to enhance grid current quality.
Boost Converter Control with MPPT Algorithm:
The boost converter is crucial for efficiently transferring power from the PV panel to the grid. The MPPT algorithm, specifically Perturb and Observe (P&O), is employed. The algorithm adjusts the duty cycle of the boost converter based on the PV voltage and current to maximize power extraction. The simulation demonstrates the effective tracking of the maximum power point.
Double-Tuned Filter Design:
The article delves into the design of the double-tuned filter, which is essential for mitigating harmonic distortions in the grid current caused by nonlinear loads. Design parameters, such as inductor and capacitor values, are calculated based on the PV power, output voltage, and input voltage of the boost converter. The simulation results indicate the successful reduction of total harmonic distortion (THD) in the grid current.
Grid-Connected PV System Performance:
The simulation results are presented with and without the presence of a nonlinear load. Without the nonlinear load, the grid current exhibits nearly sinusoidal behavior, achieving a THD below 5%. However, when introducing a nonlinear load, the THD increases significantly. The implementation of the double-tuned filter successfully reduces the THD to an acceptable level.
Conclusion:
In conclusion, the MATLAB-based approach outlined in this article provides a comprehensive understanding of modeling and controlling a grid-connected PV system. The incorporation of the MPPT algorithm for boost converter control and the integration of a double-tuned filter for harmonic mitigation showcase effective strategies to optimize the system's performance. The presented results highlight the significance of these control measures in ensuring efficient power transfer and maintaining grid current quality in the presence of nonlinear loads.