Norm combination constrained set-membership function-based approach with limit cycle oscillator control of grid-interactive photovoltaic system

This study presents a norm combination constrained set-membership function (CCSMF)-based approach for two-stage photovoltaic (PV) array to be used in the three-phase three-wire system. Here, the norm is introduced in the control technique to improve the response of existing approaches. The norm is the addition of the magnitudes of the load current components in a space. It is the most natural way of evaluating the various magnitude of harmonic components. In addition, the CCSMF technique furnishes harmonics disturbance rejection, current compensation, grid currents stabilisation and correction of power factor performances in order to allocate system integrated with residential non-linear loads. Further, it is used to extract the fundamental component of load currents for generating the reference currents. The range of the amplitude and frequency of the grid voltages are continuously monitored by the limit cycle oscillator-based algorithm. Under the outage of PV insolation, the voltage source converter (VSC) is switched to the compensator unit, and grid feeds power to the emergency load, which improves the utilisation factor of VSC. The presented system along with the proposed technique is tested in the laboratory and grid current total harmonic distortion is brought down within the limit of the IEEE-519 standard.