High-Voltage Loop Signal Filtering for Accurate Battery Current Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for detecting current in high-voltage loops of vehicle power batteries are inaccurate due to electromagnetic interference, leading to potential safety issues and increased costs with larger detection devices requiring higher power consumption.

Innovation Solution

An apparatus comprising a filter circuit and differential amplification circuit, connected to a processor, which filters electromagnetic interference and amplifies signals to improve current detection accuracy, using a common-mode suppression element and optional electrostatic protection capacitors to enhance signal fidelity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If electromagnetic interference filtering is enhanced to improve detection accuracy, then measurement precision improves, but device complexity increases

Engineering Contradiction:
Improvecurrent detection accuracyVSAvoidcircuit structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces an intermediary signal processing system between the high-voltage loop and the detection device. This includes a voltage division circuit that steps down high-voltage signals, followed by differential amplification circuits that amplify the divided signals, and finally subtraction circuits that compute the difference to obtain the current value. This multi-stage intermediary processing effectively filters electromagnetic interference while maintaining detection accuracy without requiring direct high-voltage connection.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct magnetic field sensing (which is susceptible to electromagnetic interference) with an electrical voltage division and differential amplification system. By converting the current measurement problem into a voltage measurement problem through ohm's law (V=IR), the system uses electrical circuit elements rather than magnetic sensors, thereby avoiding electromagnetic interference while achieving accurate current detection.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If voltage division ratio is increased to extend current measurement range, then adaptability improves, but measurement precision deteriorates

Engineering Contradiction:
Improvecurrent measurement rangeVSAvoiddetection accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent implements a dynamic voltage division ratio adjustment mechanism that allows the system to adapt to different current measurement ranges. The voltage division circuit can switch between different division ratios based on the expected current magnitude, enabling the system to maintain high measurement precision across a wide range of current values. This dynamic adjustment resolves the contradiction between measurement range and precision by optimizing the division ratio for each specific measurement scenario.

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

The solution significantly improves the accuracy of current detection in high-voltage loops, enhancing the reliability and performance of vehicle power batteries by reducing the impact of electromagnetic interference.

Implementation Method 1

a filter circuit configured to filter a signal from an element to be detected

Methodology Applied
Scientific EffectElectromagnetic interference filtering: Filter (electronic)

Implementation Method 2

a differential amplification circuit configured to amplify the filtered signal

Methodology Applied
Scientific EffectDifferential amplification: Magnetic Amplifier

Implementation Method 3

The differential amplification circuit includes a first transistor, a second transistor, and a common-mode suppression element

Methodology Applied
Scientific EffectCommon-mode suppression: Filter (electronic)

Data Source

PatentEP3477320B1Apparatus for processing signals of a high-voltage loop, detector, battery device, and vehicle
Publication Date: 2021.07.21 CONTEMPORARY AMPEREX TECHNOLOGY CO LTD
  • EP3477320B1 patent drawingFigure 1A~1B
  • EP3477320B1 patent drawingFigure 2~3
  • EP3477320B1 patent drawingFigure 4~5

AI summary

The present application provides an apparatus for processing signals of a high-voltage loop, a detector, a battery device, and a vehicle. The apparatus includes a filter circuit connected to an element to be detected and configured to filter signals from the element to be detected; a differential amplification circuit connected to the filter circuit and configured to amplify the filtered signals; and a processor connected to the differential amplification circuit and configured to process the amplified signals.