Harmonic Mitigation in Grid-connected PV Using Shunt Active Filter
Introduction:
We delve into the realm of harmonic mitigation in grid-connected photovoltaic (PV) systems, focusing on the implementation of Shunt Active Power Filters. This blog post explores a simulation model developed for effectively addressing harmonic distortions in grid currents, ensuring grid stability and power quality.
System Overview:
The simulation model comprises a PV array connected to an inverter via a boost converter, with the inverter linked to the point of common coupling through an LCL filter. Additionally, the system includes a grid, a non-linear load, and a Shunt Active Power Filter aimed at mitigating harmonic distortions. The PV array's rating is specified at 100.2 kilowatts, with 47 power strings, each consisting of 10 series-connected modules.
Control Logic Implementation:
Control logic is crucial for regulating the boost converter and the inverter to optimize power generation and mitigate harmonics. The boost converter is controlled using Perturb and Observe Maximum Power Point Tracking (P&O MPPT) to extract maximum power from the PV array. The inverter is controlled using voltage and current controllers, employing a feedforward decoupling control concept for efficient power delivery.
Simulation Model Details:
The simulation model incorporates transfer functions, PLL controllers, and control algorithms to accurately simulate the behavior of the PV system and the Shunt Active Power Filter. Various parameters such as PV power, grid voltage, grid current, and DC link voltage are monitored to assess the system's performance under different conditions.
Performance Analysis:
The simulation model is subjected to different scenarios, including changes in load conditions and the addition of non-linear loads. Results show that harmonic distortions in the grid current are effectively mitigated after integrating the Syntactive Power Filter. The Total Harmonic Distortion (THD) of the grid current is reduced to below 5%, ensuring compliance with power quality standards.
Conclusion:
The simulation model demonstrates the effectiveness of Shunt Active Power Filters in mitigating harmonic distortions in grid-connected PV systems. By integrating advanced control strategies and filter technologies, it is possible to enhance grid stability and ensure power quality. This approach holds significant promise for improving the performance and reliability of renewable energy systems in real-world applications.