Local penetration-free control approach against numerous changes in PV generation level in MAS-based protection schemes

Abstract

Despite the increasing attention paid to multi-agent systems (MASs), their applications in protection schemes of distribution networks would face serious challenges when the generation level of photovoltaic (PV) systems is significantly increased, i.e. the inherent variable generation of PV systems would not only increase the communication burden, but it can also cause protection miscoordination. To solve this problem, this study first classifies the protection tasks into two hierarchical categories as the ‘first-control-level’ and ‘second-control-level’ functions, where the first group is responsible for the urgent task of fault clearing, and the second group updates protection settings in the event of network/generation changes. Given clearing the fault should be accomplished as soon as possible, the first-control-level functions are designed to require the least possible data communication. Presenting a penetration-free approach, the study next describes the mechanism of managing the various generation-change events through a first-control-level function. Therefore, communication failure, as well as protection miscoordination risks, would be mitigated. Finally, the effectiveness of the proposed method is demonstrated using a practical PV-integrated distribution network. This study tackles an important challenge in the protection of distribution systems with a high level of distributed generation penetration where MAS-based schemes are applied.