On determinig the control techniques embedded in a commercial single-phase grid-tied PV inverter

Grid-tied photovoltaic inverter manufacturers rarely reveal the type of power electronic circuit topology and the type of technique used to track maximum power, control of power injected into the grid, and method used to avoid islanding operation. In this paper, an attempt is made to gain such information on a commercial 2.5 kW inverter by measuring the voltage and current waveforms under normal operation and during utility outages, analyzing such waveforms, and replicating these through computer simulations. The experience gained from such an academic exercise is found to be very valuable to students.