Fault current profile on a PV dominated distribution feeder is rather different than a conventional feeder. To estimate the fault current profile on such a feeder, the paper proposes a new method which extends the capability of conventional short-circuit analysis method. The paper also shows that this time varying fault current profile makes it also more difficult to estimate the time it will take for an overcurrent relay/device to interrupt such a fault current. The paper proposes a method for estimation of this operating time also. Performance of the proposed methods has been assessed by simulations on a sample distribution feeder.

This paper investigates the spread of the high frequency current emission between devices of different size and the grid. The impact of the EMC filter, either LCL or CLC configuration, has been considered from a simplified model. The high frequency current emission, produced by a large device, can potentially cause a relatively large current flowing through a nearby small device. An important conclusion from the study is that current amplification can occur due to harmonic resonances between different types of filters.