Design and Performance Analysis of a Hybrid Grid-connected PV System: A Case Study of Wakanda Estate's 1.5MWh Solar Installation

Due to technological advancements, there are efforts globally to lessen the generation of carbon dioxide, one of the gases responsible for the greenhouse effect. Renewable energy has seen tremendous growth in recent years. In order to protect the environment from pollution and provide electricity from an endless source for future generations, renewable energy sources, particularly solar energy via photovoltaic systems have come to stay.

This paper simplified the process, control mechanism and cost benefit of connecting solar farm (Wakanda estate as case study) for hybrid applications, directly connected to the grid with an inverter during high power demand or as standalone off grid system using batteries for energy storage when supply to the grid is not needed. Due to the intermittent nature of solar irradiance, an MPPT (Maximum Power Point Tracking) is applied to the topology. The MPPT algorithm must strike a compromise between maximizing power extraction and power quality issues, especially harmonic distortion brought on by switching elements, when interacting with the grid to dynamically modify the operating voltage to harness the most power possible under a variety of environmental conditions. The control mechanism commonly adopts a cascaded structure where the MPPT determines appropriate voltage references while an inner current control loop manages grid synchronization.

Filters play a dual role in the management of harmonics in solar PV system. Despite its usefulness in removing chopped signals, filter dynamics (usually LCL configurations) must be taken into consideration since they can present resonance issues that have the potential to also destabilize the system if not well managed, particularly when irradiance changes quickly. In order to preserve stability during grid disruptions and guarantee that power quality criteria are fulfilled by adaptive filtering, advanced MPPT implementations and include anti-islanding protection, low-voltage ride-through capabilities, and dynamic impedance matching.

The process was investigated by modeling and simulating photovoltaic arrays in MATLAB-Simulink using solar cell block from SimElectronics where influence of variable elements such as solar radiation was checked against performance of photovoltaic cells.