Impact of midpoint STATCOM on the coordination between generator distance phase backup protection and generator capability curves

In this paper, investigations are carried out to explore the impact of a midpoint STATCOM on the coordination between the generator distance phase backup protection (function 21) and the generator capability curve. The results of these investigations have shown that the midpoint STATCOM has an adverse effect on such coordination. Such an impact varies according to the fault type, the fault location and the generator loading. The dynamic simulations of a test benchmark have been conducted using the PSCAD/EMTDC software.