Selectivity Studies in São Vincente Island


Selectivity Studies in São Vincente Island


Cape Verde – Mindelo (São Vicente Island)



Cape Verde’s Water and Energy Utility (ELECTRA)








This project was a part of the project “Energy Losses Reduction and Power Quality Improvement Program”, which consisted of 8 projects, each targeting a different area with the objective to reduce energy losses and to improve its quality.

This particular Project objective was to review existing protection systems settings in order to improve safety, quality of energy and service continuity.




This Project was developed for ELECTRA (national Utility of Cape Verde) under the Losses reduction and Quality Improvement Program. It has begun in May 2013 and comprised the grid modeling of the three major islands (Santiago, São Vicente and Sal) and selectivity studies in order to define the optimized settings for the protection systems to ensure safety and energy quality.




This selectivity study was part of the enhancement measures included in the “Programa de Redução de Perdas e melhoria da Qualidade da Energia Eléctrica” project, where an array of activities intended to strengthen and improve the stability, the reliability and the quality of the Cabo Verde electrical system are being carried out by ELECTRA S.A.R.L. and Gesto Energia.

The purpose of this selectivity study was to provide robust tools on which to base a part of the future actions and works that would improve the quality and the continuity of the electric energy supply of Santiago, São Vicente and Sal islands.

In this study, a power system analysis comprising electrical network modeling, load flow and short-circuit calculations, dynamic stability analysis and a complete protection system assessment has been performed. The objective of these analyses is to identify system weaknesses in order to achieve an improvement of the electrical network in terms of stability, protection and reliability.

For each one of the three islands a different document has been submitted. The present report covers the analyses, conclusions and the opportunities of improvement of the Santiago, Sal and São Vicente electrical Networks. The more relevant aspects included in this document are:

  • Low flow and short-circuit calculation results.
  • Dynamic stability analysis
  • Protection system analysis.
  • Current problems and weaknesses identification.
  • Recommendations to improve the protection system.
  • Coordination curves.


Calculations and simulations have been performed using Siemens PSS®Sincal 11.5 software.



  • High voltage and medium voltage grids modeling and  simulation
  • Grid and selectivity studies
  • Supply and installation of grid simulation software PSS Sincal®
  • Grid studies and simulation training
  • Existing protection settings review and list of recommendations preparation