Simulation of decentralised multi-terminal power-electronic systems adequate for solar farms

From many practical problems the need for simulating complex grids including the connected devices with independent control and switching frequency arises. This paper presents a simulation tool which satisfies these requirements. A relevant case for such a simulation tool is a solar farm in which many grid-interconnected independently controlled and independently switching inverters have to be simulated down to each switching event. Otherwise the various interactions of converters, filters and cables with their resonances cannot be judged sensibly. The advanced simulation concept which combines the simulation of individually controlled power electronics with the interaction of energy-storing elements like capacitors and inductors linked by cables is introduced. The capability of the presented approach is proven by simulation results of a multiterminal system containing four three-phase two-level inverters connected to one DC grid.