A micro-energy system contains a variety of energy conversion and storage equipment. The energy consumption characteristics of energy conversion equipment usually strongly depends on the operation conditions. Based on the improved coupling model of micro energy system under different working conditions which describes characteristics of the system more accurately. Firstly

the optimal planning problem is modeled with an aim of system economy. Then

considering the uncertainties of renewable energy input

load and environmental factors

scenarios under variable off-design conditions are introduced. In order to reduce the complexity of the solution

the optimal problem is divided into master problem of equipment capacity configuration and primal problem of multistage power allocation by decomposition method. Finally

a micro-energy system which involves electricity

natural gas

and heat is configured under the proposed model and the linear model respectively. The result shows that the off-design conditions of the equipment has a significant effect on the system planning result

and it needs to be considered in the planning and design of the microgrid in order to achieve reasonable configuration and improve economic efficiency.