Influence of a high precision current sensor for improving the efficiency of PV power systems

Maximum power point tracking (MPPT) techniques are employed in photovoltaic (PV) systems to maximize the PV array output power which depends on solar irradiance and temperature. Most of these techniques depend on the measurement of the current sensor which needs to be simulated on the design phase. Simulation tools like Matlab/SIMULINK, PSpice, Multisim. etc, don´t simulate the practical behaviour of measurement devices and only deal with ideal characteristics which make it difficult to understand the exact response of such system on the operation mode. Current sensor model is implemented to enhance the design and the implementation of the proposed modified P&O algorithm. The algorithm is designed in order to overcome the drawbacks in traditional P&O MPPT algorithm. Varying the step size value and the sampling time reduces the oscillations around the MPP and leads to a faster response. When a step change in the solar irradiance occurs, the step size and sampling time are automatically tuned according to the operating point. If the operating point is far from the MPP, it increases the step size and decreases the sampling time which enables a fast tracking ability with smaller oscillation steps around the MPP.