Design and Modelling of Microgrids Operated at Constant Frequency and with a Power Level of Megawatts

Hardware prototyping of large-scale autonomous microgrids is costly and dangerous. To reduce such risks, this chapter adopts a fixed-time-step multi-rate modelling in Matlab/Simulink to reduce the differences between modelling and hardware implementation. For a comparison purpose, single-rate modelling has also been conducted. Furthermore, phasor-domain analytical solutions of the voltages at each bus in the microgrid have also been sought and are compared with results from both single-rate and multi-rate modelling. The chapter will demonstrate that the results from multi-rate modelling are closer to those from phasor-domain analysis. Moreover, the influence of DC link voltage on the real and reactive power tracing for each inverter will be demonstrated.