Abstract
This work present semi quasi source inverter (SQSI) that operate on two active state without the application of shoot through mode. An H∞ (H infinity) controller was developed using a generalized plant obtained from SQSI for PV grid connected system. The SQSI reduces the stresses on circuit component, provides ample and also limit the start-up in rush current for power quality and reliability. A salp swarm-based Maximum Power Point Tracking (MPPT) algorithm was used to track the maximum power from the PV (photovoltaic) and closed loop system was obtained to monitor the entire network. The simulation results obtained from MATLAB/Simulink environment guaranteed the system performance. The results obtained were compared with the results obtained when quasi- admittance source inverter (QYSI) were used. The Fast Fourier Transform (FFT) analysis showed that the THD was reduced from 0.67% to 0.61%. This shows that the SQSI is a transfomerless kind of inverter and outperformed the THD value obtained from the QYSI a transformer based. Due to low level of harmonics in the current waveform. The tracking efficiency of the system also improve from 97.1% to 99.68% using the salp swarm algorithm. The frequency deviation as result of sudden load variation was monitored which kept the output voltage and current almost in phase with an improve power factor from 0.90 to 0.96 as compared with robust controller for grid connected quasi admittance source inverter (QYSI) for PV system.

Key words: Semi Quasi Source Inverter; H Infinity Controller; Fast Fourier Transform; Harmonics; Frequency