ACTIVE EQUALIZATION CIRCUIT ANALYSIS.pptx

This inconsistency in the battery pack can be handled through equalization. after getting the equalization parameters like OCV and SOC. Active equalization can then be carried out

1. ACTIVE EQUALIZATION CIRCUIT TOPOLOGY OF LITHIUM-ION BATTERY PACK: A REVIEW Presented At Hybrid International Conference of the Department of Mechatronic Engineering, University of Nigeria, Nsukka.  

2. Introduction The global energy crisis has increased the focus on sustainable energy solutions. Lithium-ion batteries (LIBs) are crucial in electric vehicles (EVs) and energy storage systems. Their advantages include high energy density, low cost, and rechargeability. Inconsistencies in the internal and exterior environments of lithium-ion cells once they are connected as a battery pack can significantly limit the pack's capacity

3. Cell Balancing

4. Overview of Active Equalization Circuits Various active equalization methods: Cell-to-Cell Energy Transfer Cell-to-Pack Energy Transfer Pack-to-Cell Energy Transfer Uses DC/DC converters and selection switches.

5. Cell-to-cell energy flow technique Uses a DC/DC converter with an array of selection switches. Advantage: Faster balancing speed compared to other methods. Challenge: Requires many switching elements, leading to low equalizing efficiency. Optimization efforts focus on improving efficiency and reducing complexity.

6. Cell to pack energy flow technique Uses a single DC/DC converter to transfer energy from an overcharged cell to the entire battery pack. Advantage: High equalization speed due to significant voltage difference. Challenge: Low balancing efficiency caused by transformer losses. Research focuses on improving efficiency while maintaining high speed.

7. Pack to cell energy flow technique Transfers charge from the battery pack to an undercharged cell. The DC/DC converter connects the pack to the identified cell. Similar to the cell-to-pack technique, but in reverse direction. Focus on optimizing efficiency and minimizing energy losses.

8. Switched Capacitor Topology Title:  Switched Capacitor (Flying Capacitor) Content: Principle: Uses capacitors to transfer energy between adjacent cells. Advantages: Simple design, low cost. Disadvantages: Slow balancing, limited to adjacent cells. Visual: Circuit diagram of a switched capacitor topology.

9. Inductive Topology Title:  Inductive (Transformer-Based) Content: Principle: Uses inductors or transformers to transfer energy. Advantages: High efficiency, fast balancing. Disadvantages: Complex design, higher cost. Visual: Circuit diagram of an inductive topology.

10. DC-DC Converter Topology Title:  DC-DC Converter (Buck-Boost) Content: Principle: Uses bidirectional DC-DC converters to transfer energy. Advantages: High flexibility, fast and efficient balancing. Disadvantages: Complex control circuitry, higher cost. Visual: Circuit diagram of a DC-DC converter topology.

11. Multi-Winding Transformer Topology Title:  Multi-Winding Transformer Content: Principle: Uses a single transformer with multiple windings. Advantages: High efficiency, simultaneous balancing. Disadvantages: Complex design, large transformer size. Visual: Circuit diagram of a multi-winding transformer topology.

12. Modular Multilevel Converter Topology Title:  Modular Multilevel Converter (MMC) Content: Principle: Uses a modular approach with multiple sub-converters. Advantages: Scalable for large packs, high efficiency. Disadvantages: High cost and complexity. Visual: Circuit diagram of an MMC topology.

13. Conclusion Battery equalization is vital for LIB efficiency and longevity. Active equalization offers superior performance over passive methods. Ongoing research aims to optimize equalization topologies for improved energy management.