Research on Frequency Conversion Control Strategy Based on Self-Heating Series Resonant Topology of Lithium-Ion Battery

Lithium-ion batteries are an important part of new energy storage systems due to their high energy density, long life and lightweight characteristics. However, Lithium-ion batteries can experience significant performance degradation at low temperatures, potentially leading to issues such as lithium-ion metal deposition and battery short-circuiting. These conditions can trigger thermal runaway, spontaneous combustion, explosions, and other safety hazards. In this paper, according to the relationship between the switching frequency and the heating performance, a finite-time control strategy combined with an variable frequency control approach is employed to achieve rapid heating of lithium-ion batteries to suitable temperatures in cold environments, based on the topology of the discharge self-heating circuit in a series resonant configuration. Simultaneously, when the temperature is slightly elevated, the control system can lower the switching frequency to enable soft-switching operation. This ensures heating efficiency while simultaneously reducing switching losses, thereby enhancing the safe and stable operation of the lithium-ion battery.