A Second Order-Second Order Generalized Integrator for Three - Phase Single – Stage Multifunctional Grid-Connected SPV System

This study presents a multifunctional inverter for a three - phase single - stage grid - connected SPV system with SO-SOGI based control algorithm. The SOSOGI based quadrature signal generation (QSG) estimates the magnitude of source voltage and load current signal and phase - locked loop (PLL) estimates phase angle of the grid voltage. This estimation is used to design the proper control algorithm which improves the power quality such as reactive power compensation, harmonic rejection; DC offset rejection and in addition to feed the SPV energy to load and grid. Perturb and Observe (P&O) based maximum power point tracking (MPPT) is used for estimating reference PV voltage signal and power. The SO-SOGI based controller tracks the signal even under distorted grid supply conditions such as voltage sag / swell, harmonics to improve the dynamic response. These multifunctional capabilities of the inverter make the system more efficient for feeding the SPV energy to grid. Various operating conditions are shown to validate the proposed control algorithm using MATLAB / Simulink.