MPP control of a photovoltaic energy system

Photovoltaic (PV) power converters are used to convert the electrical energy from the PV modules to a stable and reliable power source. The object of this paper is to analyse and design a DC/DC converter with current regulation for PV energy systems. An on-line tracking method with a discrete time control and a PI compensator is used to track the maximum power points (MPPs) of the PV modules. With the temperature-loop and insolation-loop control, the proposed MPPT control features accurate MPPT and fast transient response. The large- and small-signal model and transfer function for the system are developed by using the principle of energy conservation. The T1320C25 digital signal processor (DSP) was used to implement the proposed online MPPT control. Simulations and experimental results show excellent performance.