Battery Management System Using Total Amount of Charge Determination

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Solution Overview

Problem

Current battery management systems lack an accurate method for determining the state of charge (SOC) of batteries in electric vehicles, which is crucial for efficient charging and discharging operations.

Innovation Solution

A battery management system that includes sensors to measure pack current and voltage, a state of health (SOH) measurer, a total amount of charge (TAC) determiner, and an output unit, using a look-up table (LUT) to calculate and deliver the SOC value to the engine control unit (ECU), enabling accurate SOC measurement by determining the total amount of discharge accumulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional battery management systems are used, then the system structure is simple, but the SOC measurement accuracy is insufficient

Engineering Contradiction:
ImproveSOC measurement accuracyVSAvoidsystem structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The battery management system is divided into multiple functional modules: sensor module for detecting pack current and voltage, SOH measurer for determining state of health, TAC determiner for calculating total amount of charge, and SOC measurer for computing state of charge. This segmentation allows each module to perform its specific function with high precision while maintaining clear system architecture.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces intermediate calculation steps and components: the TAC determiner acts as an intermediary between the sensor inputs and the final SOC calculation, using look-up tables and cumulative discharge tracking to bridge raw measurements with accurate SOC determination. This intermediary processing enhances measurement accuracy without requiring direct complex hardware modifications.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If SOC measurement methods are not implemented, then the system is simple, but charging and discharging operations cannot be efficiently managed

Engineering Contradiction:
Improvecharging/discharging operation efficiencyVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system continuously monitors pack current and voltage through sensors, calculates SOH and TAC based on cumulative discharge data, and determines SOC in real-time. This feedback loop provides the ECU with accurate battery status information, enabling efficient charging and discharging operations while managing battery health and performance.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The TAC determiner performs preliminary calculations by accumulating discharge amounts over time and maintaining look-up tables of charge-discharge relationships before the final SOC measurement is needed. This preliminary processing of discharge data prepares the system for rapid and accurate SOC determination when required for operational decisions.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP1777794B1Battery management system and method of determining a state of charge of a battery
Publication Date: 2018.05.02 SAMSUNG SDI CO LTD
  • EP1777794B1 patent drawingFigure 1
  • EP1777794B1 patent drawingFigure 2
  • EP1777794B1 patent drawingFigure 3

AI summary

The battery management system (BMS) measures a state of charge (SOC) of a battery by using a total amount of charge corresponding to a total amount of discharge accumulation. The BMS, outputting a SOC of a battery to an engine control unit (ECU), includes a sensor, state of health (SOH) and SOC measurers, a total amount of charge (TAC) determiner, and an output unit. The sensor detects a pack current and a pack voltage of the battery. The SOH measurer outputs a SOH of the battery by using the pack current and voltage. The SOC measurer measures a SOC of the battery by using the pack current and a TAC of the battery. The TAC determiner accumulates a total amount of discharge accumulation by using the pack current, determines a TAC corresponding to the total amount of discharge accumulation, and delivers the determined TAC to the SOC measurer. The output unit outputs the SOC and SOH to the ECU.