Diversified frequency regulation resources are an effective and inevitable approach for addressing frequency safety issues in new power system. With the differentiated frequency regulation strategy, an optimization configuration method for battery storage is proposed, coupling long-term planning with short-term unit combination in multiple scenarios. This method constructs joint frequency regulation strategies for thermal-storage, wind-storage, and solar-storage respectively, refining the various functions of battery storage to significantly enhance its flexibility in the frequency regulation process. The model aims to minimize investment and operation costs of the wind-solar-thermal-storage system. The model incorporates constraints of system frequency response power and high-order multi-machine system frequency response time-domain simulation for frequency safety. The effectiveness of the proposed method is validated through an improved IEEE 24 node system. It is demonstrated that battery storage can flexibly choose among various functions, such as smoothing fluctuations, reducing renewable energy curtailment, and participating in frequency regulation. The optimal frequency safety-economy solution is achieved.