Voltage support control of unbalanced distribution systems by reactive power regulation

The high penetration of distributed generation (DG) into distribution networks (DN) has highlighted the necessity to develop proper control techniques to supply customers with high power quality levels and to offer ancillary services to the distribution system operators (DSOs). This paper supposes an unbalanced DN in which the importance of applying voltage control strategies is largely justified in literature. In particular, we present a strategy that offers the mandatory voltage control ancillary service, able to avoid active power production curtailments, using the minimum reactive power for the regulation. Validation of the proposed control has been conducted on the IEEE 13-bus distribution system and the obtained results are encouraging.