Battery Pack Voltage Equalization with Ripple Filtering

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Solution Overview

Problem

Existing battery equalization devices generate ripple waves that destabilize battery voltage, reducing the effectiveness and lifespan of battery packs.

Innovation Solution

A device comprising a sampling unit, an analog-to-digital converting unit, a control unit, an equalization unit, and a filter unit that samples and converts voltage signals, generates driving signals for equalization, and filters out ripple waves to stabilize battery voltages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the energy dissipation circuit works constantly to equalize battery voltages, then the voltage equalization effect is improved, but the batteries remain in charging or discharging state which influences their capacity and generates ripple causing voltage instability

Engineering Contradiction:
Improvevoltage equalization effectivenessVSAvoidbattery voltage stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent implements periodic sampling of battery voltages at predetermined intervals rather than continuous monitoring. The control unit activates the energy dissipation circuit only when voltage differences exceed a threshold, creating a periodic rather than continuous operation mode. This reduces ripple generation while maintaining effective equalization over time.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent extracts and removes the harmful ripple waves generated during equalization using a filter circuit. The filter is specifically designed to eliminate ripple components from the battery voltage, separating the useful equalization function from the harmful ripple effect.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If continuous voltage monitoring and equalization is implemented, then voltage equalization is improved, but energy consumption increases and battery capacity is influenced

Engineering Contradiction:
Improvevoltage equalizationVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system performs voltage sampling at predetermined periodic intervals rather than continuously. The control unit compares sampled voltages and activates equalization only when necessary (when voltage differences exceed thresholds), significantly reducing energy consumption while maintaining effective equalization.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The control unit activates the energy dissipation circuit only when voltage differences exceed a predetermined threshold, rather than continuously. This partial action approach reduces energy consumption by engaging equalization only when actually needed, while still achieving effective voltage balancing.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP2342795B1A device for equalizing voltage of a battery pack
Publication Date: 2016.09.14 BYD CO LTD
  • EP2342795B1 patent drawingFigure 1~2
  • EP2342795B1 patent drawingFigure 3
  • EP2342795B1 patent drawingFigure 4

AI summary

The present invention provides a battery pack voltage equalization device comprising: a sampling unit which samples the battery voltage signals of the battery pack according to a sampling control signal; an analog-to-digital converting 5 unit which converts the sampled voltage signals into a digital voltage signal; a control unit which generates the sampling control signal and a driving signal based on the digital voltage signal; an equalization unit which equalizes the voltage signals of the battery pack based on the driving signal; a filter unit which is connected to the equalization unit and the battery pack. The present invention 10 applies the filter unit to filter out the ripple signal generated during equalization.