Grid-Voltage Synchronization Algorithms based on
Phase-locked Loop for Power Converter under
Balanced and Unbalanced Conditions
Journal:
GRENZE International Journal of Engineering and Technology
Authors:
S.K.Das, J.K.Moharana, P Syam
Volume:
6
Issue:
2
Grenze ID:
01.GIJET.6.2.513
Pages:
327-335
Abstract
Rapid integration of non-conventional energy sources connected to grid and
distribution systems with electronic power circuits has altered the planned grid
specifications to ensure adequate grid failure efficiency. One of the essential control unit’s
components is phase locked loop(PLL),where power converter grid is connected it. A
synchronous reference frame (SRF) PLL approach is proposed in this research for
obtaining correct phase knowledge for unbalanced grid voltages. The PLL efficiency was
tested for abnormal grid conditions like unbalance, voltage sag, phase jump etc. This paper
presents SRF PLL's analysis for the non-ideal grid conditions, where SRF-PLLs are
implemented with pre-filters. Exact measurement of grid’s fundamental frequency and
phase angle is important for grid connected power converter circuit’s control algorithm.
The pre-filters which are used with SRF-PLL are band pass filter and low pass filter, in
which band pass filters can be used to minimize input harmonics and low pass filter can
reduce input noise. The implementation has been done through MATLAB software.