Background: Microgrid is an effective integration mode of distributed generation (DG).
It can eliminate the negative effect caused by the intermittent DG and consume the energy locally.
Methods: For a public distribution network, a microgrid performs as a controllable and flexible unit.
However, when the public distribution network has the demand of flexible regulation, there is no
reasonable quantitative indexes to evaluate the flexibility of microgrid for dispatching decision. For
this problem, the operational flexibility indexes of a microgrid are defined in this paper.
Results: The indexes are quantified according to the maximum energy and active power regulation
margin of each flexible equipment in the microgrid. The operational flexibility of microgrid is closely
related to the scheduling strategy. Therefore, the corresponding dispatching model of a microgrid
is also provided in this paper.
Conclusion: A case study shows how to calculate and use these flexibility indexes in an operation
cycle of a microgrid system with energy storage (ES) facility and demonstrates the availability and
practicability of the evaluation indexes and the method.