Battery Rack Voltage Balancing Without External Power Supply

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Solution Overview

Problem

Existing methods for balancing voltages between battery racks in electric vehicles and energy storage systems require a separate power supply device, leading to increased operational costs.

Innovation Solution

An apparatus comprising a voltage measuring unit, a collecting unit, and a control unit that measures and balances voltages between battery racks without a separate power supply, by selectively discharging and charging racks with the highest and lowest voltages to maintain uniform voltage levels, and repeatedly performing balancing operations based on State of Charging (SOC).

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a separate power supply device is used for voltage balancing between battery racks, then voltage balancing can be achieved, but operational costs increase

Engineering Contradiction:
Improvevoltage balancing capabilityVSAvoidoperational cost
Core Design Contradiction:
ReliabilityVSUse of energy by stationary object

Solution Approach 1:

The patent implements self-service by enabling battery racks to balance their own voltages through mutual energy exchange. The control unit identifies voltage differences between racks and directs energy flow from high-voltage racks to low-voltage racks, eliminating the need for external power supply devices and reducing operational costs while maintaining voltage balancing capability

Inventive Principle:
Principle #25Self-service

2Stability of the object's composition

If voltage balancing is performed between all battery racks, then uniform voltage levels are achieved, but system complexity increases

Engineering Contradiction:
Improvevoltage uniformityVSAvoidbalancing system complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the battery system into multiple racks that independently participate in voltage balancing. Instead of treating the entire battery system as a single unit requiring centralized control, each rack is monitored individually and can exchange energy with other racks based on voltage differences, simplifying the overall control architecture while achieving voltage uniformity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control unit dynamically adjusts balancing operations based on real-time voltage parameters. By continuously monitoring voltage levels and adjusting energy flow directions and magnitudes according to measured voltage differences, the system achieves adaptive voltage uniformity without requiring complex predetermined control schemes

Inventive Principle:
Principle #35Parameter changes

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

Enables voltage balancing between battery racks without the need for a separate power supply device, reducing operational costs while maintaining optimal SOC levels.

Implementation Method 1

discharge the battery rack having the second lowest voltage and charge the battery rack having the lowest voltage by using a discharged current

Methodology Applied
Scientific EffectBattery discharge and charge: Battery (electricity)

Implementation Method 2

discharge the battery rack having the highest voltage and charge the battery rack having the second highest voltage by using a discharged current

Methodology Applied
Scientific EffectBattery discharge and charge: Battery (electricity)

Data Source

PatentEP3223387B1Apparatus and method for voltage balancing between battery racks
Publication Date: 2019.04.03 LG CHEM LTD
  • EP3223387B1 patent drawingFigure 1
  • EP3223387B1 patent drawingFigure 2
  • EP3223387B1 patent drawingFigure 3

AI summary

The present invention relates to an apparatus and a method of balancing voltages between battery racks, and the apparatus includes: a voltage measuring unit configured to measure a voltage of a plurality of battery racks; a collecting unit configured to collect the measured voltage of the plurality of battery racks; and a control unit configured to control voltage balancing to be performed between two battery racks among the plurality of battery racks based on the collected voltage of the plurality of battery racks, and control the voltage balancing to be repeatedly performed between the battery racks, on which the voltage balancing is performed, and the battery rack, on which the voltage balancing is not performed.