Abstract
Solar photovoltaics in Malta have increased substantially over the years, both at large scale and residential scale. The present installed capacity is already having a negative impact on Malta’s grid infrastructure, causing problems due to the reverse power flows (resulting from oversupply) and related issues such as voltage rise. This paper considers the integration of the »LVRSys® Low-Voltage Regulation System« in a low voltage grid in a semi-rural area in Malta.
A thyristor-controlled transformer-based Low Voltage Regulator was modelled and simulated in MATLAB/Simulink using the PLECS blockset. Experimental results were also obtained via measurements of the voltage profiles at 70% of the actual low voltage feeder that showed several instances of over and under voltage events. The outputs obtained from the simulation model strongly agreed with those obtained from the field testing thereby validating the simulation models that were developed in this study. Results show that the voltage in the low-voltage grid was successfully regulated to around the nominal voltage of 240 V.
Click here to read the full application report and to download the report for free:

LVRSys®
The »LVRSys® – Low-Voltage Regulation System« was developed to solve voltage stability problems due to the integration of electromobility, photovoltaics and heat pumps in the low-voltage grid. It represents an economical and flexible alternative to costly and time-consuming line extensions.
Authors
John Licari: Conceptualization; data curation; formal analysis; investigation; methodology; resources; software; validation; visualization; writing—original draft.
Cyril Spiteri Staines: Conceptualization; data curation; formal analysis; investigation; methodology; resources; software; validation; visualization; writing—original draft.
Alexander Micallef: Conceptualization; data curation; formal analysis; investigation; methodology; resources; software; validation; visualization; writing—original draft.
Stefan Hoppert: Conceptualization; writing—review and editing
Acknowledgements
This research was funded by the Energy and Water Agency under the National Strategy for Research and Innovation in Energy and Water (2021-2030), grant agreement number REVOLT EWA 65/22. The authors would also like to thank the Maltese Distribution System Operator (DSO/VNB) “Enemalta plc” (DSO) for providing access to the »LVRSys®« and the data required to conduct this study.