Modelling and control of photovoltaic panels utilising the incremental conductance method for maximum power point tracking

For photovoltaic panels, maximum power point tracking (MPPT) is a crucial process to ensure energy capture is maximised. Various tracking algorithms are available for this purpose. Of these, one of the more common presently implemented is the incremental conductance method. However, no linearised small signal model incorporating an incremental conductance-based MPPT process exists. As will be demonstrated, this is attributed to the formation of a degenerate model when conventional linearisation techniques are applied. In this study, a modelling approach is developed that overcomes this deficiency and permits linearisation of the incremental conductance MPPT algorithm. As a case study adopting this developed approach, a complete small signal dynamic model of the incremental conductance method utilising a boost converter is derived. The model is validated against simulations in PSCAD/EMTDC. This study also presents some applications of the model, such as controller design and stability testing. The results demonstrate that the system is highly robust to variations in the lighting condition.