Behavioral modeling of grid-connected photovoltaic inverters: Development and assessment

• A behavioral model for grid-connected PV inverters is proposed and assessed.
• Inverter parameters and DC-measurements are not needed to fit the model parameters.
• The proposed model provides suitable results under power dynamics or voltage dips.
• Real data from different PV power plant configurations are used to assess the model.
• Comparison results with previous approaches are also included in the paper.

This paper describes and assesses a behavioral model for grid-connected photovoltaic inverters. The model allows us to simulate the electrical behavior of commercial single-phase and three-phase inverters in accordance with the limits of EN50160 power quality. Regarding power strategies for current inverters, both voltage and current control loops have been explicitly modeled, providing suitable simulations of the injected AC-current waveform under either power dynamics or grid voltage disturbances. Additionally, irradiance oscillations and dynamic Maximum Power Point Tracking performance have been also considered in the proposed solution. Internal inverter variables are not needed to fit the model parameters, being estimated from basic data-sheet information provided by manufacturers and simple AC-collected values from the PV power plants. This characteristic avoids any additional DC-side measurement, being a significant contribution in comparison with previous approaches.The proposed model is assessed using real data collected in Spanish photovoltaic power plants along several years. The obtained results are compared with previous behavioral model approaches and also included in the paper.