Synchronverter small-signal modelling and eigenvalue analysis for battery systems integration

The high penetration of renewable energy sources in electrical distribution networks is giving rise to new challenges in the low voltage network operation. Power electronics converters are widely used to connect these energy resources to the grid, and the control technique that emulates the operation of synchronous generators is attracting the attention of researchers in recent years. Such converters are referred to as synchronverters and they have been recently studied in the literature. This paper presents the modelling and analysis of a battery-supported synchronverter connected to the grid. Each dynamic element of the system is modelled in detail and all of them are then joined together forming a state-space model. The eigenvalue analysis was then used to evaluate the synchronverter robustness against variations in the grid inductance and resistance. The theoretical developments were validated experimentally on a 15 kVA prototype of a synchronverter connected to the grid. The small signal modelling procedure showed to be an accurate approach to represent synchronverters dynamics.