GNLMP Control for Solar PV-Battery Based Microgrid with Ms-EPLL Synchronization

This paper deals with an adaptive graph signal processing (GSP) normalized least mean pth (GNLMP) current control algorithm for renewable energy integrated system. Conventional algorithms for current control in micro grid system suffers from stability margin issue. This algorithm filters the existing signal corrupted by non-Gaussian noise. The steady-state response becomes more stable due to its fast convergence and robust behaviour. Voltage control is generally preferred for islanded conditions to set voltage and frequency for connected local consumer loads. In reconnection with the utility grid, synchronization with the utility phase is necessary because the phase angle mismatch causes transient current spikes, which are detrimental to the lifespan of the power electronic interface. For the issue of synchronization, more-stable enhanced PLL (Ms- EPLL), having a better stability margin, is used and compared to conventional enhanced PLL. This system integrates double stage solar PV array with a battery associated directly at DC link. The focus of this work is mainly two-fold, i.e., grid-integrated control to improve power quality (PQ) and synchronization technique to reduce the current spikes that can damage the semiconductor switches in the power converters of the micro grid (MG) system. The obtained results show acceptable dynamic and steady-state behaviour in MATLAB/Simulink R2020b. The power quality of the grid current waveform is shown to have satisfactory THD (Total Harmonic Distortion) less than 5%.