Robust Control for PMBLDCG Based WEC System and Seamless Grid Synchronization

Abstract

A three phase three wire based microgrid (MG) consisting of permanent magnet brushless DC generator (PMBLDC) based wind energy conversion system (WECS) is demonstrated in this paper. This paper presents the performance enhancement of a non conventional energy system (NCE) based microgrid for the seamless grid synchronization. This paper presents dynamic controls for grid connected and islanded modes of operation. For grid connected mode (GCM), a quadrature third order generalized integrator and frequency locked loop and multilayer harmonic decoupling network (QTOGI-FLL-MHDN) based control algorithm is used. The problems like voltage imbalance, DC offset, swell/sag, fluctuation in power produced by WECS, are successfully taken care by QTOGI-FLL-MHDN. The quadrature component of load fundamental is extracted with QTOGI-FLL-MHDN. For standalone mode (SAM), a resonant and proportional resonant (R+PR) control is presented. For the synchronization technique to perfectly track the phase and frequency, a dual TOGI (DTOGI) is combining with the phase locked loop (PLL). This improves the system response under frequency deviation. During frequency variation, it effectively follows the voltages of the grid and the load and it is adjustable to different conditions of grid. Total harmonic distortions (THDs) of are in the boundaries of the IEEE-519 standard.