Compressed air energy storage（CAES） is one of the effective means to achieve peak-shaving target and promote wind power utilization. However

the efficiency of CAES mainly depends on its operating conditions. Its off-design characteristics have direct impact on the secure and efficient operation of wind-storage hybrid system. Consequently

aiming at maximizing profit of the hybrid system

we established a coordinated optimization model in which the off-design characteristics of CAES are taken into account. The proposed model accurately describes the dynamics of the compressor and turbine

and the piecewise linearization method is used to linearize off-design characteristics curve so as to formulate a mixed integer linear programming problem. Case study results indicate that the profit estimations are more realistic compared to constant efficiency model. By considering the operational constraints and dynamic efficiency

the actual operation state of CAES can be more accurately investigated

which can provide a basis for the operational decision of wind-storage hybrid system.