Bidirectional Converter Control for Multi-Battery SOC Imbalance
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Solution Overview
Problem
Electric mobility vehicles equipped with multiple batteries face challenges in maintaining balanced state of charge (SOC) levels, leading to reduced driving distance and motor output due to uneven battery conditions.
Innovation Solution
A method and system for battery management that involves receiving SOC information from multiple batteries, determining the difference between the highest and lowest SOC levels, and controlling the charging or discharging of batteries using bidirectional converters to balance the SOC levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If multiple batteries are used to drive the electric mobility, then energy efficiency and driving distance are improved, but SOC imbalance occurs leading to reduced driving performance
Solution Approach 1:
The control unit continuously monitors SOC information from multiple batteries and dynamically adjusts power flow control signals to converters based on real-time SOC differences. This feedback mechanism detects SOC imbalance and automatically initiates balancing operations, ensuring driving performance is maintained while utilizing multiple batteries for extended range
Solution Approach 2:
The system uses the existing converter infrastructure and battery resources to perform self-balancing without external intervention. The control unit orchestrates power transfer between batteries using the converters, allowing the battery system to self-correct SOC imbalances and maintain optimal operating conditions
2Device complexity
If batteries with different SOCs are used, then system complexity is reduced, but motor torque and output are reduced
Solution Approach 1:
The control unit performs preliminary balancing actions by detecting SOC differences before they significantly impact motor performance. By proactively transferring charge between batteries when imbalances are detected, the system prevents torque reduction while maintaining simple operational protocols
Solution Approach 2:
The converters serve multiple functions: power conversion for motor operation and inter-battery charge transfer for SOC balancing. This multi-functionality allows the system to maintain motor output by using the same power conversion infrastructure for both propulsion and battery management, avoiding additional complex balancing hardware
Data Source
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AI summary
A method and system for battery management of an electric mobility are provided. The method for battery management of the electric mobility may comprise: receiving information related to states of charge (SOCs) of a plurality of batteries installed in the electric mobility; determining whether a difference between a SOC of a first battery having a highest SOC and a SOC of a second battery having a lowest SOC among the plurality of batteries exceeds a predetermined threshold value; and controlling charge and/or discharge of at least one of the plurality of batteries by controlling power flow of at least one of a plurality of converters connected to the plurality of batteries.