Capacitor Module Balancing via Relative Capacitance Feedback
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Solution Overview
Problem
Existing capacitor module systems face challenges in balancing voltages across multiple modules due to capacitance differences, leading to inefficiencies and potential damage from excessive cell voltage, especially at high voltages, as current methods fail to fully discharge individual cells across multiple modules to zero volts.
Innovation Solution
A system comprising a processing unit and communication circuit that determines relative capacitance across modules and balances cells by adjusting voltages based on average cell voltage values, allowing for coordinated balancing across multiple modules, including active and passive dissipation components to efficiently manage voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If capacitor modules are connected in series configuration, then the system voltage increases, but voltage imbalance between individual cells worsens due to capacitance differences
Solution Approach 1:
The system continuously monitors the voltage of each individual cell in the series configuration and uses this feedback information to activate balancing circuits that dissipate excess voltage from cells that are above the average voltage, thereby maintaining voltage balance across all cells while operating at high system voltages
Solution Approach 2:
The system dynamically adjusts the resistance values of the balancing circuits based on the measured voltage differences between cells, changing the dissipation rate to optimize the balancing process while maintaining the high voltage series configuration
2Reliability
If prior balancing systems are used, then some voltage balancing is achieved, but they cannot fully discharge individual cells to zero volts when the series configuration is discharged
Solution Approach 1:
Each cell in the series configuration has its own dedicated balancing circuit that can independently dissipate voltage from that specific cell, allowing the system to fully discharge each cell to zero volts regardless of the overall series configuration voltage state, thereby achieving complete discharge efficiency
3Adaptability or versatility
If capacitance differences between capacitors exist, then production variations and aging occur, but no balancing system can handle high voltage series configurations across multiple modules
Solution Approach 1:
The system divides the high voltage series configuration into individual cell-level control units, with each cell having its own balancing circuit that can independently manage voltage dissipation, allowing the system to handle high voltages while preventing excessive voltage in any single cell due to capacitance variations or aging
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 ensures balanced cell voltages across all modules, preventing premature aging and damage by dynamically adjusting system voltage, allowing all cells to reach their failure points simultaneously, thereby maintaining optimal performance and extending the lifespan of capacitor modules.
Implementation Method 1
A capacitor's charge and voltage is proportional to its capacitance value. Accordingly, any energy storage system using multiple capacitors in a series configuration may encounter voltage imbalance problems caused, at least in part, by capacitance differences between the multiple capacitors.
Data Source
AI summary
In one aspect, the invention comprises an apparatus for balancing cells in a series string of modules having cells. The apparatus comprises a processing system and a communication circuit. The processing circuit is configured to receive an average cell voltage value from each module. The processing circuit is further configured to determine an overall average cell voltage for all the cells. The processing circuit is also configured to cause each the modules to determine a relative capacitance for each of its cells and cause each of the modules to balance its cells based on the respective relative capacitances. The communication circuit is configured to receive the average cell voltage value from the modules.