RPNLMMES Control for Double-Stage SECS-BES Based Three-Phase Microgrid with MSCLO-FLL Synchronization

This paper deals with the synchronization and improved power quality capabilities of solar energy conversion systems (SECS) at distorted three phase distribution grid, common to developing and under-developed nations. The configuration consists of double-stage three phase SECS with on- grid and off-grid operating modes. A robust proportionate normalized least mean M-estimate square (RPNLMMS) based control is utilized for grid power injection mode of operation, which has impulse noise rejection ability. Synchronization is implemented through multi-stage circular limit oscillator (MSCLO) frequency locked loop (FLL) structure. These multiple CLO structures are employed to reject the dominant 5
^th
and 7th harmonic orders components from the frequency and phase angle estimates. The SECS along with its controls are designed in MATLAB/Simulink R2020b platform and is subjected to various dynamic variations, which yield satisfactory dynamic and steady-state behaviours. The total harmonic distortion (THD) of the grid current waveform is found to be less than 5%.