Impact of Using Current Limiting Reactor on the Existing Circuit Breakers in Micro-Grids

Recently, distributed generations (DGs) have been widely used in distribution networks. Using DGs in the grid-connected mode leads to increase of the fault current level. This increase can affect the existing equipment especially circuit breakers (CBs) and operation of overcurrent relays. Current limiting reactor (CLR) has been proposed to reduce the effect of micro-grids (MGs) on the existing protection scheme during fault conditions by many researchers. However, there are some factors for interrupting the current by CBs which do not only depend on the fault current magnitude. Transient recovery voltage (TRV) and rate of rise recovery voltage (RRRV) can also affect the operation of CBs. This paper presents the equivalent analysis of the TRV and RRRV across a CB connected with a CLR. The transient stability is studied through simulation of a practical network, which shows the impact of using CLRs on the burden of CBs. In addition, some possible solutions are studied in this paper.