The core questions
A microgrid combines diesel generation, PV, storage converters and local load, and the controller has to manage transfer between grid-connected and islanded operation, frequency and voltage support and power redistribution within a few hundred milliseconds. That behaviour can only be verified with real controllable load; simulation results are not a substitute.
Test items
Typical items: voltage and frequency transients on planned and unplanned islanding; load-step response while islanded; power-sharing accuracy between storage and generation; the ability to pick up load in stages during a black start; and stability across a range of load power factors.
Load equipment configuration
Microgrid work needs load banks that step quickly, resolve finely and support inductive and capacitive loading, driven by a test control system that runs the load profile from a script and records all electrical quantities. On site, containerised and mobile banks are the practical choice for transport and for paralleling to reach the required capacity.