Synchronization method and frequency tracking applied on voltage converters

Abstract

This paper proposes a new closed-loop synchronization method for single-phase voltage converters. It presents a good performance under highly distorted grid voltages. Moreover, it has a good performance in terms of distortions in the synchronization signals and it has a good transient performance due amplitude, frequency and angle disturbances. In addition, a frequency adaptation algorithm is proposed for applications where large frequency variations are expected, such as in weak grids. This method can be extended for three-phase systems, applied in three-phase PWM converters. Experimental results using a DSP are given to demonstrate the good performance of the proposed synchronization method.