Battery Detection Circuit Common Ground Isolation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing battery detection circuits face accuracy issues due to interference from isolation units, which are necessary to isolate high voltage ground signals from sampling units, leading to increased complexity and cost.

Innovation Solution

A battery detection circuit with a simplified structure where all sampling units are connected to a common low voltage ground, eliminating the need for additional isolation units and improving signal accuracy by using relays and resistor networks for voltage sampling and insulation detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an isolation unit is added to isolate high voltage ground signal from sampling unit, then high voltage isolation is improved, but device complexity and cost increase

Engineering Contradiction:
Improvehigh voltage isolationVSAvoidcircuit structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the isolation function with existing circuit components (relays and resistor networks) rather than adding a separate isolation unit. The relays serve dual purposes: signal switching and electrical isolation, while resistor networks provide both voltage division and isolation functionality. This merging approach achieves high voltage isolation without increasing device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The relays in the circuit perform multiple functions simultaneously: they act as switches for signal acquisition, provide electrical isolation between high voltage and low voltage circuits, and enable insulation detection. This multi-functionality eliminates the need for dedicated isolation components, reducing overall circuit complexity while maintaining isolation effectiveness.

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

2Reliability

If an isolation unit is added to isolate high voltage ground signal from sampling unit, then high voltage isolation is improved, but manufacturing cost increases

Engineering Contradiction:
Improvehigh voltage isolationVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges isolation functionality into existing relays and resistor networks that are already part of the battery detection circuit. By utilizing components that are already necessary for signal sampling and insulation detection, the design avoids additional isolation components, thereby reducing manufacturing cost while maintaining high voltage isolation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The relays serve multiple purposes including signal switching, electrical isolation, and insulation detection. This multi-functionality reduces the total component count and eliminates the need for separate isolation units, directly reducing manufacturing cost while achieving the required high voltage isolation performance.

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

3Reliability

If isolation unit is used to separate high voltage and low voltage grounds, then high voltage protection is improved, but measurement precision deteriorates due to introduced interference

Engineering Contradiction:
Improvehigh voltage protectionVSAvoidsampled signal accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent introduces resistor networks as intermediary elements between high voltage and low voltage circuits. These resistor networks provide galvanic isolation while maintaining signal integrity, acting as mediators that transfer measurement information without introducing the interference problems associated with traditional isolation units. The relays also serve as intermediaries, providing clean switching without ground loop interference.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3451003B1Battery detection circuit and battery management system
Publication Date: 2021.03.10 CONTEMPORARY AMPEREX TECHNOLOGY CO LTD
  • EP3451003B1 patent drawingFigure 1
  • EP3451003B1 patent drawingFigure 2
  • EP3451003B1 patent drawingFigure 3

AI summary

The present disclosure provides a battery detection circuit and a battery management system. The battery detection circuit includes a positive relay (Gl), a negative relay (G2), a first positive sampling unit (F1), a first negative sampling unit (F2), a second positive sampling unit (F3), a second negative sampling unit (F4), and a reference voltage terminal (GND), wherein: all of the first positive sampling unit (F1), the first negative sampling unit (F2), the second positive sampling unit (F3), the second negative sampling unit (F4) and a power battery pack to be detected are connected to the reference voltage terminal (GND). With the battery detection circuit and the battery management system of the present disclosure, both the cost of the battery detection circuit and the complexity of the structure of the battery detection circuit can be reduced. [Fig. 1]