Frequency Gating Battery Equalization Current Control

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Solution Overview

Problem

Conventional equalization current adjustment methods are limited in flexibility, allowing adjustments only within a narrow range, which affects the accuracy of State Of Charge (SOC) calculation in battery packs with equalization functions.

Innovation Solution

The method involves determining the actual equalization current value of a battery unit by obtaining the fundamental amplitude of the alternating current power supply and voltage gain, and adjusting these parameters to ensure the current falls within a preset threshold, using a frequency gating battery pack active equalization apparatus.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If driver pulse width is adjusted to control equalization current, then equalization current can be regulated, but the adjustment range is limited and flexibility is low

Engineering Contradiction:
Improveequalization current adjustment flexibilityVSAvoidadjustment range
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent changes the control parameter from driver pulse width to alternating current frequency. By adjusting the frequency of the alternating current power supply, the equalization current can be controlled over a wide range with high flexibility, resolving the limitation of narrow adjustment range associated with pulse width modulation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces a dynamic control mechanism where the alternating current frequency can be continuously adjusted based on the energy differences between battery units. This dynamic adjustment capability enables the system to adapt to different equalization requirements, achieving both wide adjustment range and high flexibility

Inventive Principle:
Principle #15Dynamics

2Productivity

If equalization current is increased to equalize battery units with large energy differences, then equalization speed improves, but SOC calculation accuracy decreases due to current sensor measurement errors

Engineering Contradiction:
Improveequalization speedVSAvoidSOC calculation accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent introduces alternating current frequency as an intermediary control parameter between the equalization requirement and the actual equalization current. By controlling the frequency of the alternating current power supply, the system can achieve precise control of equalization current magnitude, enabling both high equalization speed and accurate SOC calculation

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements a feedback mechanism where the control unit continuously monitors the energy differences between battery units and adjusts the alternating current frequency accordingly. This closed-loop control ensures that the equalization current is precisely controlled at each stage, maintaining both fast equalization and accurate SOC measurement

Inventive Principle:
Principle #23Feedback

3Ease of operation

If frequency gating active equalization apparatus is used, then equalization current can be controlled, but device complexity increases compared to conventional equalization circuits

Engineering Contradiction:
Improveequalization current control capabilityVSAvoidcircuit structure complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent makes the alternating current power supply serve multiple functions: it provides power to the battery unit while simultaneously serving as the equalization current source. The frequency gating circuit controls both the power delivery and equalization current magnitude through a single control mechanism, reducing overall system complexity despite the advanced control capability

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

Data Source

PatentEP4054050B1Equalization current adjustment method and related apparatus
Publication Date: 2023.08.02 HUAWEI TECH CO LTD
  • EP4054050B1 patent drawingFigure 1
  • EP4054050B1 patent drawingFigure 2
  • EP4054050B1 patent drawingFigure 3-a

AI summary

An equalization current adjustment method and a related apparatus are provided, so as to resolve a prior-art problem that an equalization current may be adjusted only in a narrow range with low flexibility. The method includes: determining a to-be-equalized battery unit in a battery pack, and obtaining a current actual equalization current value of the to-be-equalized battery unit; and when it is determined that a difference between the current actual equalization current value of the to-be-equalized battery unit and a target equalization current value does not fall within a range of a preset threshold, adjusting a fundamental amplitude of an alternating current power supply of a target circuit on which the to-be-equalized battery unit is located and/or a voltage gain of the target circuit, so that the difference between the current actual equalization current value of the to-be-equalized battery unit and the target equalization current value falls within the range of the preset threshold.