An open-source platform for modelling, simulation, and performance analysis of multi-converter, mixed-generation power systems

Abstract

Existing power system modelling and simulation tools are chiefly developed for analysing conventional grids that operate close to nominal frequency during disturbances; as such they are inadequately suited to analyse modern renewable generation sources, which may transiently operate in off-nominal frequencies and over much broader timescales. This warrants development of improved analytical tools for emerging converter-dominated systems. Existing simulation platforms, such as electromagnetic transient (EMT) and transient stability (TS) simulators, provide accuracy and computational efficiency, but are also limited in terms of analytical tools required for drawing broader general conclusions. This paper presents a systematic method to develop and expand positive-sequence, average-value analytical models of converter-based generation systems. The paper develops a new open-source platform for converter-dominated grids, which enables additional analyses including small-signal stability assessment, state trajectory analysis, and controller optimization. Using the proposed method, performance and stability matrices can be readily obtained to assess multi-converter, multi-machine systems. Due to its implementation in decoupled phasor domain, the developed method provides faster performance than existing time-domain simulators, whilst retaining its accuracy in off-nominal frequencies. The developed platform and its capabilities are exemplified using an IEEE benchmark system.