High-Voltage Interlock Device Isolation Circuit

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Solution Overview

Problem

Existing high-voltage interlock devices face safety issues due to direct connection of high-voltage components to fault detection devices, which can lead to damage from large external voltages, compromising the safety of the system.

Innovation Solution

The implementation of a high-voltage interlock device with isolated signal detection circuits that convert original electric signals into sampled signals, ensuring the high-voltage interlock component is isolated from the fault diagnosis module, preventing direct connection and potential damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If high-voltage components are directly connected to fault detection devices, then fault detection capability is improved, but safety is worsened due to potential damage from large external voltages

Engineering Contradiction:
Improvefault detection capabilityVSAvoiddamage from large external voltages
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an isolation circuit as an intermediary component between the high-voltage interlock component and the fault diagnosis module. This isolation circuit includes galvanically isolated relay circuits that transfer signal states without direct electrical connection, allowing fault detection while blocking harmful high voltages from reaching the detection device.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent divides the detection system into separate galvanically isolated segments. The high-voltage side (interlock component) and low-voltage side (fault diagnosis module) are segmented into independent electrical domains, with signal transmission achieved through isolated relay circuits rather than direct connection.

Inventive Principle:
Principle #1Segmentation

2Object-affected harmful factors

If isolation circuits are introduced to protect against high voltage, then safety is improved, but device complexity increases

Engineering Contradiction:
Improveprotection from high voltageVSAvoidcircuit structure complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The isolation circuit uses galvanically isolated relay circuits as intermediary components that provide protection while maintaining a relatively simple structure. The relay circuits transfer binary signal states (connected/disconnected) without requiring complex isolation hardware, thus balancing protection with simplicity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3943956B1High-voltage interlock device and fault detection method thereof
Publication Date: 2023.03.29 CONTEMPORARY AMPEREX TECHNOLOGY CO LTD
  • EP3943956B1 patent drawingFigure 1~2
  • EP3943956B1 patent drawingFigure 3~5A
  • EP3943956B1 patent drawingFigure 5B~5D

AI summary

The embodiments of the application provide a high-voltage interlock device and a fault detection method thereof. The circuit includes: a first signal detection circuit, configured to collect a first original electric signal from a high-voltage interlock component under detection and convert the first original electric signal into a first sampled signal while ensuring that the high-voltage interlock component under detection is isolated from a fault diagnosis module; a second signal detection circuit, configured to collect a second original electric signal from the high-voltage interlock component under detection and convert the second original electric signal into a second sampled signal while ensuring that the high-voltage interlock component under detection is isolated from the fault diagnosis module; the fault diagnosis module, configured to determine a fault of the high-voltage interlock component under detection according to the first sampled signal and/or the second sampled signal, under a condition that at least one of the first switch module and the second switch module is in an OFF state. The solution provided by the embodiments of the application avoids damage to the controller caused by a large external voltage, and can improve safety of the high-voltage interlock device.