The paper reports the power quality improvement of a grid-connected three-phase voltage source converter (VSC) aimed at interfacing electrochemical energy storage to the power system. Two control algorithms have been synthesized and experimentally validated, considering an LCL-filter VSC that implements a current feedback control on a synchronous reference frame. The comparison between a proportional-integral (PI) controller with a hybrid one, characterised by the joining of PI and resonant (R) controllers, specifically designed for reducing the effects of fifth and seventh voltage harmonics, has been performed. The PI-R controller outcomes show a significant improvement concerning PI one regarding the total harmonic distortion of the injected converter current for output power values lower than the 30% of rated one. This solution permits the extension of the lower power limit for which the current total harmonic distortion is lower than 5%, till to 18%. Therefore, the hybrid PI-R controller results are suitable for those applications, such as the energy storage system, requiring power quality in an ample range of working operative conditions.
Attenuation of Voltage Distortion Effects on a Three-Phase Grid-Connected Converter
Mauro Boi;Andrea Floris;Alessandro Serpi;Alfonso Damiano
2023-01-01
Abstract
The paper reports the power quality improvement of a grid-connected three-phase voltage source converter (VSC) aimed at interfacing electrochemical energy storage to the power system. Two control algorithms have been synthesized and experimentally validated, considering an LCL-filter VSC that implements a current feedback control on a synchronous reference frame. The comparison between a proportional-integral (PI) controller with a hybrid one, characterised by the joining of PI and resonant (R) controllers, specifically designed for reducing the effects of fifth and seventh voltage harmonics, has been performed. The PI-R controller outcomes show a significant improvement concerning PI one regarding the total harmonic distortion of the injected converter current for output power values lower than the 30% of rated one. This solution permits the extension of the lower power limit for which the current total harmonic distortion is lower than 5%, till to 18%. Therefore, the hybrid PI-R controller results are suitable for those applications, such as the energy storage system, requiring power quality in an ample range of working operative conditions.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.