Ultracapacitor Module Balancing via Microcontroller Voltage Monitoring

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Solution Overview

Problem

Existing capacitor modules in series, particularly ultracapacitors, face premature aging due to non-uniform voltage and temperature conditions, leading to uneven lifespan among capacitors, which results in module failure and energy dissipation during balancing attempts.

Innovation Solution

An electronic board with digital control, utilizing a microcontroller for monitoring and balancing ultracapacitors, implements end-of-charge protocols based on individual capacitor conditions, employs active and passive balancing methods, and communicates with other modules to maintain uniform voltage and charge levels, using thermistors for temperature monitoring and dissipative devices for voltage regulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If capacitors are deployed in series modules with fixed numbers, then the system can achieve high-power applications, but one capacitor failing earlier than neighbors causes the entire module to be taken out of service

Engineering Contradiction:
Improvehigh-power application capabilityVSAvoidmodule reliability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The system divides the series module into individually monitorable capacitor units with distinct voltage monitoring and balancing circuits, allowing selective management of each capacitor's charge state to prevent premature module failure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system implements continuous voltage monitoring and feedback control through microcontrollers that adjust charging/discharging operations based on real-time capacitor voltage states, preventing any single capacitor from failing early and taking down the entire module

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If capacitors are binned according to measured characteristics, then manufacturing precision improves, but later events can still age one capacitor faster than another

Engineering Contradiction:
Improvecapacitor characteristic uniformityVSAvoidcapacitor lifespan uniformity
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The system dynamically adjusts charging and discharging operations for each capacitor based on real-time voltage measurements and individual capacitor states, rather than relying solely on static manufacturing binning, to equalize aging rates across all capacitors

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes operational parameters (voltage levels, charging/discharging rates) for individual capacitors based on their real-time state, allowing capacitors with slightly different manufacturing characteristics to age uniformly through adaptive control

Inventive Principle:
Principle #35Parameter changes

3Duration of action of stationary object

If voltage load is controlled to prevent premature aging, then capacitor lifespan extends, but energy dissipation occurs during balancing operations

Engineering Contradiction:
Improvecapacitor lifespanVSAvoidenergy dissipation during balancing
Core Design Contradiction:
Duration of action of stationary objectVSLoss of energy

Solution Approach 1:

The system uses intermediary energy storage elements and controlled discharge paths that allow voltage balancing between capacitors without direct energy dissipation, using the capacitors themselves as intermediaries to redistribute energy

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system recovers energy that would otherwise be dissipated during balancing operations by redirecting it through controlled discharge paths, allowing energy to be stored or reused rather than lost

Inventive Principle:
Principle #34Discarding and recovering

4Reliability

If temperature and voltage are monitored and controlled, then uniform aging is achieved, but device complexity increases

Engineering Contradiction:
Improveuniform capacitor agingVSAvoidmonitoring and control system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system uses multi-functional microcontrollers that perform voltage monitoring, temperature monitoring, balancing control, and communication functions in single integrated units, reducing overall system complexity despite the comprehensive monitoring required

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system combines temperature sensors, voltage monitoring circuits, and control logic into integrated modules for each capacitor, reducing the number of separate components and simplifying system architecture

Inventive Principle:
Principle #5Merging (Combining)

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 extends the lifespan of capacitors by maintaining uniform voltage and temperature conditions within modules, reducing energy dissipation and preventing premature aging, while allowing for efficient balancing and communication between modules.

Implementation Method 1

uses thermistors for temperature monitoring

Methodology Applied
Scientific EffectThermistor: Thermistor

Implementation Method 2

dissipative devices for voltage regulation

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3101765B1Maximizing life of capacitors in series modules
Publication Date: 2018.02.14 MAXWELL TECHNOLOGIES INC
  • EP3101765B1 patent drawingFigure 1~2
  • EP3101765B1 patent drawingFigure 3~4
  • EP3101765B1 patent drawingFigure 5

AI summary

A device (1) monitors and/or balances an ultracapacitor (3) and/or a module (4) comprising a plurality of ultracapacitors (3) connected in series, the module (4) being connectable in series or in parallel with other modules (4). The device comprises an electronic board (2) comprising digital control and/or command means, such as a microcontroller (5), executing a program for monitoring and balancing the ultracapacitor (3) and/or the module (4). The relative capacitances of the capacitors are measured, and this information is employed to determine when to carry out a controlled discharge of particular capacitors. Temperature information is also employed to determine when to carry out a controlled discharge of particular capacitors. In this way the lifetime of any particular capacitor is, desirably, extended to be no shorter than the lifetime of other longer-lived capacitors in the module.