Use of Kalman filters for renewable energy sources isolation transformers current harmonics compensation

This paper is focused on the analysis of a Kalman filter performance when introduced in the current control loop of a distributed generator connection inverter. The goal is to use this kind of filter to reduce the harmonic content of the currents injected by this equipment in their point of common coupling. The study has been performed by means of simulation, using Matlab-Simulink, and by implementing the filter on a DSP in our lab. Both, simulation and experimental results, clearly demonstrate that this kind of control system can improve the response produced by the inverters. The elimination of certain well-known noisy harmonics introduced by an element such as the isolation low voltage transformer has been in this way accomplished.