Current Sensor Diagnosis via Voltage-Current Charge Comparison

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Solution Overview

Problem

Current sensors in battery packs face challenges in accurately diagnosing their functionality, leading to potential overcharging or overdischarging issues due to the complexity of diagnosing circuits.

Innovation Solution

An apparatus and method that calculate change values of voltage-based and current-based charged charge amounts using a processor, comparing these values to diagnose the current sensor's accuracy and adjust the normal range based on temperature measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a diagnosing circuit is added to diagnose current sensor accuracy, then the diagnostic capability is improved, but the device complexity increases

Engineering Contradiction:
Improvecurrent sensor accuracyVSAvoiddiagnosing circuit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The current sensor diagnosing apparatus utilizes existing components (voltage measuring unit, current measuring unit, and processor) that are already part of the battery management system to perform self-diagnosis of the current sensor. The processor compares change values of voltage-based charged charge amount and current-based charged charge amount to determine sensor accuracy, eliminating the need for separate dedicated diagnosing circuits.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The voltage measuring unit and current measuring unit serve dual purposes: they monitor battery parameters for normal operation and simultaneously provide data for current sensor diagnosis. The processor performs both battery management functions and sensor diagnostic functions using the same hardware resources, making the system multi-functional without increasing component count.

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

2Measurement precision

If temperature compensation is implemented to improve diagnosis accuracy, then the measurement precision is improved, but the device complexity increases

Engineering Contradiction:
Improvediagnosis accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The processor adjusts the normal range for current sensor diagnosis based on temperature parameters. When temperature changes are detected, the system dynamically modifies the acceptable error range between voltage-based and current-based charged charge amount comparisons, allowing accurate diagnosis across varying temperature conditions without adding physical compensation components.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3748388B1Apparatus and method for diagnosing current sensor
Publication Date: 2023.12.27 LG ENERGY SOLUTION LTD
  • EP3748388B1 patent drawingFigure 1
  • EP3748388B1 patent drawingFigure 2
  • EP3748388B1 patent drawingFigure 3~4

AI summary

The present disclosure relates to an apparatus and method for diagnosing a current sensor, which may effectively diagnose whether a current sensor provided to a battery pack is normal. The apparatus for diagnosing a current sensor includes: a voltage measuring unit configured to measure a both-end voltage of the cell assembly; a current measuring unit configured to measure a current flowing through the charging and discharging path; and a processor configured to diagnose the current sensor based on a change value of a voltage-based charged charge amount and a change value of a current-based charged charge amount.