Modeling of a PV plant for integration studies
An important building company was preparing a photovoltaic farm project in Central America. Hence, they contacted our consulting service to model their solar farm in CYME Software.
Model
We began by reviewing the farm data to identify which data were lacking. This allowed ensuring a realistic model could be created even if experience-based assumptions on data were made.
The first step was to choose the range of the model. It included all the farm’s power system from inverters to connection point to the grid. To optimize simulation time while preserving accuracy, each inverter was agglomerated with its upstream panels.
Fig1. Solar panels agglomerated model
For most of cables, we used their geometry to accurately estimate their impedances and admittances.
Panels main characteristics describing their V-I curve were implemented.
All inverters static parameters were implemented, including their efficiency, their power limits, and their Volt-Watt control. Dynamic characteristics were not available. However, we made sure the farm model was functioning for transient stability and long-term dynamic analyses. We gave specific explanations to clients about how they could improve their model if any additional data becomes available.
Fig2. Solar panel power limits
Conclusion
Finally, we integrated inverters harmonics profile to panels model. Before delivering the model to client, we validated it with the following tests:
- A Load-Flow analysis to confirm the solar panels production is of desired amount
- A load increase to check panels power production varies on voltage drop as expected
- A harmonic analysis to check current harmonics were as desired