Battery Charge Balancing via DC/DC Converters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing load balancing devices for power batteries with multiple series-connected electrochemical accumulators face inefficiencies in energy transfer, leading to excessive energy dissipation and reduced service life due to complex structures and high operational costs, as well as vulnerabilities in control circuit malfunctions.
Innovation Solution
A load balancing device comprising converters connected to each stage of the battery, with a transformation law that regulates output voltage based on current delivery, allowing for efficient distribution of current between stages and minimizing unnecessary losses by prioritizing discharge of the most charged stages, thus optimizing charge balancing without complex interdependent regulation loops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If energy-dissipating balancing systems are used to equalize voltage across battery stages, then charge balancing is achieved, but excessive energy is consumed and dissipated as heat
Solution Approach 1:
The patent introduces an intermediary energy transfer mechanism using capacitive coupling between battery stages. Instead of directly dissipating energy from overcharged stages, the invention uses coupling capacitors to transfer excess energy to undercharged stages, acting as a mediator that enables energy redistribution without direct dissipation.
Solution Approach 2:
The invention changes the operating parameters of the balancing system by using AC coupling signals superimposed on the DC battery voltage. This allows energy transfer through capacitive coupling at specific frequencies, transforming the balancing approach from DC resistance-based dissipation to AC capacitance-based transfer, thereby reducing energy loss.
2Measurement precision
If complex interdependent regulation loops are implemented in balancing devices, then precise voltage control is achieved, but system complexity and cost increase
Solution Approach 1:
The patent implements a self-service balancing mechanism where the system automatically detects voltage imbalances and initiates energy transfer without complex external control. The coupling capacitors and associated circuitry automatically respond to voltage differences between stages, eliminating the need for sophisticated regulation loops while maintaining precision through passive component characteristics.
Solution Approach 2:
The invention divides the balancing function into independent modular units, each handling a specific battery stage with its own coupling capacitor. This segmentation allows each module to operate independently with simple control logic, reducing overall system complexity while achieving precise control through the combined effect of multiple simple modules.
3Power
If multiple battery stages are connected in series to achieve high voltage, then power output is increased, but voltage differences between stages cause incomplete charging/discharging
Solution Approach 1:
The patent uses coupling capacitors as intermediaries between series-connected battery stages to enable energy transfer. These capacitors facilitate the redistribution of energy among stages with different charge levels, allowing the high-voltage series configuration to maintain high productivity by ensuring all stages reach optimal charge states.
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 solution enhances the efficiency of charge balancing, reduces energy dissipation, and simplifies the system architecture, improving the service life and cost-effectiveness of the battery management system while maintaining robustness against control circuit malfunctions.
Implementation Method 1
converters, for example, one per stage of battery (2), respectively applying output voltages (vs1 to vsk) and providing output currents (i1 to ik), the outputs of which are connected to an auxiliary network (6)
Data Source
Figure 1~2
Figure 3~5
Figure 6~7
AI summary
The invention concerns a device (3) for balancing the charge of an electric power storage device (2) including a plurality of electrical storage elements (Et1,... Etk) connected in series, comprising: -at least two current limiting DC/DC converters (30i) each having: -an input intended to be connected to the terminals of a respective storage element (Eti); -an output intended to be connected to an electrical network (6) having a voltage controlled at a lower level than the voltage at the terminals of the storage device (2); -a transformation law of the following type: Vout=K1 *Ve-f(l) for l≤llim, in which Vout is the potential difference at said output, K1 is a constant, Ve is the potential difference at said input, f(l) is an affine function of current I delivered at said output and llim is the current limitation of the converter.