Modeling and stability analysis of multi-time scale DC microgrid

- A comprehensive dynamic model of multi-time scale DC microgrid is constructed.
- A reduced 2nd-order model is deduced by using arithmetic mean values.
- A reduced-order multi-scale model is proposed to reduce order and conserve dynamics.

The diverse dynamic characteristics of distributed generators (DGs) make the DC microgrid to be a multi-time scale system. This paper investigates the dynamic modeling of multi-time scale DC microgrid, and a reduced-order multi-scale model (RMM) is proposed to reduce the system model complexity as well as to conserve major time scale information. The DGs with similar time constants are grouped together to form an equivalent DG, the equivalent DGs are then combined to construct RMM. The effectiveness of the proposed RMM is verified by stability analysis, numerical simulations and experimental tests.