Establishment of second-order equivalent circuit model for bidirectional voltage regulator converter: 48 V-aluminum-ion battery pack

Abstract

The establishment of an equivalent circuit model for new-generation battery packs is an important issue related to the safety of future energy storage systems. In this study, an aluminum-ion battery pack model is accurately built by performing a hybrid pulse power characterization (HPPC) experiment, along with a synchronous regulator converter electric-circuit model of the resistor–capacitor (RC) equivalent circuit. This approach proves the feasibility of the proposed model via field testing and simulation, thereby underscoring its capability to precisely depict the exterior features of the battery discharging behavior and its advantages and disadvantages, as well as suggestions for improvement. From the analysis results, the convergent efficiency is found to exceed 90%. The simulation error was smaller than 0.08 V. The system can be incorporated with the function of current feedback to suppress current surge and stabilize battery output as well as to prevent voltage surges and damage to components caused by impulses when a load is applied.

Keywords

• Aluminum-ion battery
• Circuit equivalent model
• Bidirectional power system
• Voltage regulator converter