Synchronous generator protection in the context of microgrids

The power generation connected in parallel to the distribution network has been increasing significantly, being this procedure defined as distributed generation. Therefore, it is necessary to evaluate the behavior of this generation in the face of contingencies that may somehow reflect on damages to the equipment, focusing specifically on the associated protection functions. In this regard, this paper analyses the protection functions of overcurrent and current unbalance applied to a synchronous generator operating in parallel with the utility and also in isolated mode. According to the results obtained, it is evident that, in addition to the overcurrent relay, the current unbalance function is also required for the generator protection to operate correctly in all analyzed cases.