DOUBLE INTEGRAL SLIDING MODE CONTROL APPROACH FOR A THREE-PHASE GRID -TIED PHOTOVOLTAIC SYSTEMS

This paper presents modelling and control of maximum power point tracking (MPPT) for a three phase grid–tied photovoltaic (PV) system by using a non-linear controller namely double integrated sliding mode controller (DISMC) to enhance MPPT and to stabilize the output power of PV system. The non-linear I-V, P-V characteristics of PV systems depends upon irradiation and temperature; causes difficulty in tracking maximum power. The PV system consists of a PV panel, DC/DC boost converter and a MPPT controller to generate pulses which are fed to converter for tracking maximum power. In this paper, the performance of DISMC-MPPT shown to be effective when compared to other controllers like perturb & observe (P&O)- MPPT, adaptive P&O-MPPT, sliding mode controller (SMC)-MPPT and integral SMC (ISMC)-MPPT. The presented DISMC-MPPT method is robust, provides quicker and steady tracking maximum power with respect to the other discussed methods and also performs well during any change in weather conditions. To validate the effectiveness, the mathematical modelling of all the above mentioned non-linear controller MPPT methods and their simulations are carried on Matlab/SIMULINK