Maintenance reserve capacity is defined as a capacity to assure all units’ maintenance on time.In order to evaluate the impact of uncertainty of unit maintenance demand（UMD） and the stochastic of wind power to maintenance reserve capacity evaluation

this paper establishes a model

which considers UMD uncertainty and the impact of stochastic of wind power

and proposes an index

which is maintenance reserve not enough probability considering wind（MNEPCW）

to evaluate the maintenance reserve. In the aspect of application

this paper proposes the definition of maintenance probability and uses it to modify the forced outage rate

which can be used to conduct probabilistic production simulation

generation system and composite system evaluation

and system risk analysis. Case study uses real data of one province to evaluate the maintenance reserve and analyses the impact of speed cross-correlation and wind farm capacity to maintenance reserve evaluation

which shows that maintenance reserve increases with the cross correlation increases

maintenance reserve decreases with the wind farm capacity increases.