Three-phase single-stage grid tied solar PV ECS using PLL-less fast CTF control technique

The main intent of this study is to integrate a solar photovoltaic (SPV) generating system to three-phase grid and to provide a clean and uninterrupted flow of power at abnormal and peak load conditions. To establish such an interface, a reliable, secure and high-performance control algorithm is the necessity. This study presents a three-phase single-stage grid tied SPV energy conversion system (SPECS) using phase locked loop-less (PLL-less) fast character of triangle function (CTF) control technique. This system configures an SPV array, voltage-source inverter (VSI), ripple filters and three-phase grid with connected linear and non-linear loads. Apart from supplying active power to the grid and connected loads, SPECS also provides functionalities of an active shunt filter such as reactive power compensation, harmonics attenuation, power factor correction, load balancing and zero voltage regulation. This system uses a single-stage perturb & observe approach for maximum power point tracking. Moreover, the VSI control is based on PLL-less fast CTF technique which enhances the functioning of SPECS. The presented system is modelled, designed and simulated on MATLAB/Simulink platform as well as its functioning is validated experimentally on a developed laboratory prototype.