Precharge Circuit Switch Fusion Diagnosis in Battery Management

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Solution Overview

Problem

Existing battery management systems struggle to reliably diagnose fusion failures in both the main switch and precharge switch, which can lead to inrush currents and continuous battery discharge, and existing methods are not accurate for diagnosing precharge switch failures.

Innovation Solution

A battery managing apparatus with a precharge circuit and a diagnosing switch, along with current and voltage measuring units, is used to determine the magnitude of current flow to diagnose switch failures by comparing battery and load voltages and current values against preset thresholds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If voltage difference measurement method is used to diagnose main switch failure, then main switch fusion failure can be diagnosed, but precharge switch fusion failure cannot be diagnosed

Engineering Contradiction:

Improvemain switch failure diagnosis accuracyVSAvoidcomprehensive switch failure diagnosis capability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent divides the diagnosis process into two distinct measurement stages: first measuring voltage difference across the main switch to diagnose main switch failures, then measuring current through the precharge circuit to diagnose precharge switch failures. This segmentation allows each measurement method to be optimized for its specific diagnostic target, resolving the limitation where only main switch failures could be detected.

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If current magnitude measurement method is used to diagnose main switch failure, then main switch fusion failure can be diagnosed, but precharge switch fusion failure diagnosis becomes inaccurate

Engineering Contradiction:

Improvemain switch failure diagnosis accuracyVSAvoidswitch failure diagnosis accuracy

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent implements dynamic measurement methodology where the measurement approach changes based on the diagnostic stage: voltage difference measurement is performed first to check main switch status, then current magnitude measurement is performed to check precharge switch status. This dynamic adaptation of measurement methods ensures accurate diagnosis for each specific switch type, preventing misdiagnosis that would occur with a static single-method approach.

Inventive Principle:

Principle #15Dynamics

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

Accurately diagnoses fusion failures in both the main and precharge switches, preventing inrush currents and continuous discharge, enhancing safety and reliability in battery management systems.

Implementation Method 1

measuring a magnitude of current flowing through a power line

Methodology Applied

Scientific EffectOhm's Law: Ohm's Law

Implementation Method 2

current flows from the battery through the precharge resistor to the capacitor included in the input terminal of the load

Methodology Applied

Scientific EffectElectrical Conduction: Conduction (electrical)

Implementation Method 3

the capacitor is charged as current flows from the battery through the precharge resistor to the capacitor

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentEP4636415A1Battery management apparatus having switch failure diagnosis function, and system and method comprising same

Publication Date: 2025.10.22 LG ENERGY SOLUTION LTD

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AI summary

Disclosed is a battery managing apparatus having a switch failure diagnosing function, and a system and method including the same. The battery managing apparatus includes a main switch installed on a first line connected to one terminal of a battery; a precharge circuit including a first precharge resistor, a precharge switch, and a second precharge resistor sequentially connected in series, and connected in parallel with both ends of the main switch; a current measuring unit configured to measure current flowing through a second line connected to the other terminal of the battery; a diagnosing switch installed on a branch line that connects one end of the precharge switch and the second line; and a control unit operably coupled with the main switch, the precharge switch, the diagnosing switch and the current measuring unit. The control unit may be configured to receive a diagnosing current value from the current measuring unit when the diagnosing switch is turned on or off, and diagnose whether at least one of the main switch and the precharge switch has a fusion failure depending on the magnitude of the diagnosing current value.