Abstract: Against the backdrop of the rapid development of the new energy industry, electrochemical energy storage has emerged as a critical means to enhance grid flexibility and stability, making the importance of system selection and integration design increasingly prominent. This paper takes the energy storage project at the Teda Power 110 kV substation as a case study to systematically investigate the technical selection, integration solution, and battery management system (BMS) design of a lithium iron phosphate (LFP) battery energy storage system. By comparing the performance differences of various energy storage technologies, it demonstrates the comprehensive advantages of LFP batteries in terms of cycle life, safety, and economic efficiency. Combined with the engineering case, it elaborates on the integration logic and parameter configuration of battery cells, modules, and clusters. The research indicates that the LFP battery-based energy storage system can meet the requirements of power storage for high reliability, long lifespan, and operation across a wide temperature range. Furthermore, an intelligent BMS is identified as the core support for ensuring the system's safe and efficient operation.