Design of a power plant emulator for the dynamic frequency stability studies

Increasing renewable energy integration to grid requires inertial support to improve frequency stability of the power system. Inertial support of renewable energy systems requires hardware verification in order to test practical limitations and absence of dynamical grid simulators makes verification studies more challenging. In this study, a test rig which is composed of a DC motor, an AC synchronous generator and an external flywheel, is developed in order to provide a platform in which dynamic properties of an actual power plant can be simulated in the laboratory conditions. A 4 kVA power plant simulator with a field exciter and a speed governor is developed with 1kVA buck converters. The frequency response of the test bench is controlled in parallel with the computer simulations in Digsilent Powerfactory environment. The developed test rig is a low cost and simple solution aimed for experimental studies regarding inertial support of renewable energy systems or power system frequency studies.