Investigating the response of synchronous machines loss-of-field protection in power systems supporting dynamic reactive power compensation as ancillary service

This paper aims to demonstrate that generation stations providing dynamic reactive power compensation services to support voltage according to grid code requirements, affect the performance of the conventional synchronous generator loss-of field protection. In this context, investigations are conducted on a power station connected to the grid through a transmission line. During a complete loss-of field fault in a generator, voltage supporting ancillary services are provided by a large-scale aggregated wind park, which is tapped to the transmission line. The simulation results show that the wind park has an impact on the loss-of-field relay, mainly by delaying or accelerating the tripping time. Several critical factors, such as the generators pre-fault loading, the rated power output of the wind park, the connection point of the wind park, as well as the controller parameters of the synchronous and wind turbine generators have been investigated in the simulation analysis conducted.