Real-Time hardware-in-the-loop grid simulator to test generating units’ speed governors under islanding operating conditions

Abstract: This paper describes a hardware-in-the-loop simulator for the real-time testing of on-field speed governors within generating units. The simulator is designed to be inserted within the speed measurement loop of speed governors and to emulate a speed signal which represents the generating unit’s speed as if the unit were operating on a small and weak network. The equipment is used for testing the behavior of generating units during large frequency transients while taking account of possible non-linearity of actuators, which can drastically affect this transient. This system also provides power plant simulation, which can be used for Factory Acceptance Testing of speed governors in order to assess their functionality and to confirm parameter settings. The whole system has been rigorously tested in the field on hydro and thermal power plants and some of the more significant results are presented in this paper.