Battery Stack Balancing via Resonant Circuit
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Solution Overview
Problem
Conventional battery balancing technologies either waste power through passive balancing or require extensive time for active balancing due to the need for repeated switching operations to generate voltage differences between battery cells.
Innovation Solution
A battery stack balancing apparatus utilizing a series resonant circuit with a capacitor and inductor, along with a polarity change circuit and control unit, performs zero current or zero voltage switching during resonance periods to efficiently balance battery voltages without power wastage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If passive balancing is performed by connecting a resistor to battery cells, then voltage imbalance is corrected, but power is wasted due to energy dissipation in the resistor
Solution Approach 1:
The patent introduces a resonant circuit as an intermediary component between battery cells to enable power transfer without direct resistive connection. The resonant circuit acts as a mediator that facilitates energy exchange through electromagnetic resonance, avoiding the energy dissipation inherent in direct resistor-based balancing approaches.
Solution Approach 2:
The patent replaces the traditional electrical resistive balancing mechanism with a resonant electromagnetic field-based mechanism. By using LC resonance to transfer energy between cells, the system substitutes the mechanical/electrical resistive process with a field-based energy transfer process that minimizes energy loss.
2Loss of energy
If active balancing is performed by transmitting power via capacitor between battery cells, then power wastage is avoided, but extensive time is required due to repeated switching operations
Solution Approach 1:
The patent applies resonant oscillation principles to the electrical circuit, creating a vibrating energy transfer mechanism. The LC resonant circuit generates oscillating current that rapidly transfers energy between battery cells, analogous to mechanical vibration, thereby accelerating the balancing process without requiring slow repeated switching operations.
Solution Approach 2:
The patent utilizes periodic resonant oscillations to transfer power between battery cells. Instead of relying on slow sequential switching, the system employs rapid periodic energy exchange through resonant cycles, significantly reducing the total time required for balancing while maintaining efficient power transfer.
3Power
If conventional active balancing uses repeated switching operations to generate voltage difference, then power transfer is achieved, but the number of switches and transmission lines increases
Solution Approach 1:
The patent merges multiple switching functions into a unified resonant circuit architecture. By combining the power transfer and voltage difference generation functions into the resonant circuit itself, the system reduces the number of discrete switches and transmission lines needed, simplifying the overall device structure while maintaining effective power transfer capability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for rapid and efficient balancing of battery stacks by maximizing voltage differences between cells, reducing the number of transmission lines and switches needed, and leveraging resonance to enhance balancing efficiency.
Implementation Method 1
a series resonant circuit including a first capacitor and a first inductor connected to the first capacitor in series
Data Source
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AI summary
Disclosed is a balancing apparatus capable of performing balancing without wasting power and of rapidly transmitting power. A battery stack balancing apparatus for balancing a battery stack including a plurality of battery modules connected to each other in series includes a series resonant circuit including a first capacitor and a first inductor connected to the first capacitor in series, a polarity change circuit including a second inductor and a polarity change switch connected to the second inductor in series so as to be selectively turned on or off, and connected to the first capacitor in parallel, a plurality of transmission lines having ends, respectively, electrically connected to a plurality of nodes provided at a low-potential end of the battery stack, at a high-potential end of the battery stack, and between the plurality of battery modules connected to each other in series, and other ends connected to the series resonant circuit, a plurality of transmission switches provided on the plurality of transmission lines so as to be selectively turned on or off, and a control unit configured to control the plurality of transmission switches and the polarity change switch.