Reliable voltage monitoring system for synchronization of distributed power generation systems to utility grid

摘要

The unceasing progression of DPGS (Distributed Power Generation Systems) gives an effective and inexpensive approach, for electricity generation near by the consumer. Though for better performance, the distributed power generating stations are being allied to the utility network, there is an emergent necessity for the DPGS to work properly and uninterruptedly in case small grid instabilities. This needs developments to be made forthe control arrangement of DPGSs at the grid-side converter. As a consequence, grid interlinking necessities applied to distributed generations, are need to be continuously updated for maintaining the stability and the quality of the grid voltage. In the realm of grid interconnection, grid synchronization system is the main part of the control scheme of grid connected inverter. This is liable for extracting the phase angle of the grid voltage. One best technique, which is used today are phase-locked loops. From the beginning of the thesis a brief introduction about the distributed power generating stations is given. Later, voltage monitoring systems based on zero crossing detection (ZCD) to Phase Locked Loop (PLL) are given.A comprehensive survey aboutquadrature-signal generation, which is essential for three-phase and single-phase phase-locked-loop, is given. These QSG techniques are investigated and simulated in MATLAB-2010. Finally, thesis covers an advance synchronization approach in both three-phase and single-phasePLL with the inclusion of Second Order Generalized Integrator (SOGI). Both PLLs are experimentally verified by the use of LABVIEW-2010 with coalition with NI USB 6341