Comparison of synchronization techniques to the grid applied to single-phase inverters

Abstract

This paper presents the comparison of synchronization techniques to the grid applied to single-phase inverters. The synchronizer is used in a single-phase inverter, which is applied in an environment of microgrids. The inverter converts the energy that comes from renewable energy sources (photovoltaic, wind, fuel cell, etc.). The main objective of obtaining the phase of the grid is to achieve a power factor close to unity in the inverter. For this reason it is vital that the phase difference between the synchronizer and the grid zero. To obtain synchronizer algorithm using Linear Kalman Filter is necessary to know the Extended Kalman Filter. This allows to analyze the operation of the filter, which allows to reach reduce Linear Kalman Filter or also known as Simplified Kalman Filter. Due to the system is single phase is required orthogonal signal because the Linear Kalman Filter works with a stationary reference frame. Orthogonal signal is created with an all-pass filter. To compare the results is implemented a synchronizer using PLL, because it is the most used.