Influência de malhas de controle de velocidade no desempenho de funções de proteção anti-ilhamento de um gerador síncrono distribuído

Abstract

The integration of distributed energy resources into power systems brings concerns related to islanding operation. In the case of loss of the main grid supply, the failure of islanding detection leads to potential risks to operational safety. In this aspect, passive detection techniques such as frequency-based relays and voltage-based relays, usually associated with anti-islanding protection, are part of technical requirements for distributed generation established by utilities. Based on the literature survey, the anti-islanding protection performance is mainly affected by power system factors. However, the influence of control systems of distributed synchronous gene rators, especially the governor control, has not investigated from the perspective of islanding detection capability. In this context, this research evaluates the influence of governor control to pologies on anti-islanding protection performance, such as under/over frequency, rate of change of frequency, and under/overvoltage relays. The analyses are focused on a diesel generator set applied as a distributed energy resource into a distribution system. Islanding simulations have performed under different operational conditions, and comparative cases also include different load models, relays settings, different primer mover models, and variation of governor control gains. The additional analyses cover the representativeness of governor control into islanding studies. The relays performance evaluation has held through analysis of frequency, rate of change of frequency and voltage signal, and implementation of performance curves method referred to those relays. The results have shown some critical factors on frequency relays performance, associated with conservative cases when a particular governor control structure of a diesel generator has implemented.