Battery Pack HVIL Monitoring for Internal vs External Defect Detection
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Solution Overview
Problem
Current HVIL state monitoring methods in battery systems cannot accurately differentiate between defects inside or outside the battery pack, leading to potential hazardous situations by incorrectly identifying high voltage exposure, which may result in unnecessary power supply blockage to vehicles.
Innovation Solution
Incorporating an HVIL state monitoring apparatus with an HVIL auxiliary power supply that generates an auxiliary power signal and applies it to the HVIL signal line when the main power is stopped, using input and output switches to detect the connection state of high voltage connectors based on voltage and current measurements, and transmitting this information to an external controller for accurate defect identification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If power is provided to the HVIL from the ECU of the vehicle and returned through the HVIL of each battery pack, then the connection status of high voltage connectors can be monitored, but it cannot accurately determine whether a defect has occurred inside or outside the battery pack
Solution Approach 1:
The patent divides the HVIL monitoring function into two independent power supply modes: main power supply (from ECU) and auxiliary power supply (from battery pack). By segmenting the power supply sources and using switches to control which power source is active, the system can perform different types of measurements. The auxiliary power supply enables local battery pack testing independent of the vehicle ECU, allowing distinction between internal and external defects.
Solution Approach 2:
The patent introduces an auxiliary power supply as an intermediary device within the battery pack that can provide power to the HVIL independently of the ECU. This intermediary power source enables the battery pack to perform self-diagnosis by controlling switches to create specific circuit configurations, allowing the system to determine whether defects are internal or external to the battery pack.
2Reliability
If the ECU determines a hazardous state based on HVIL monitoring, then high voltage exposure can be prevented, but power supply may be unnecessarily blocked to the vehicle
Solution Approach 1:
The patent segments the monitoring function into two distinct modes: one for detecting external defects (using main power supply) and another for detecting internal battery pack defects (using auxiliary power supply). This segmentation allows the system to differentiate between defects that should trigger protection functions and those that do not, preventing unnecessary power supply blockage and ensuring vehicle operation continuity when appropriate.
Solution Approach 2:
The patent implements a feedback mechanism where the battery pack's auxiliary power supply and switch control system provide detailed information about the location and nature of HVIL defects. This feedback enables the ECU to make informed decisions about whether to activate protection functions, ensuring that power supply is only blocked when truly necessary for safety.
3Measurement precision
If an HVIL state monitoring apparatus is added to each battery pack, then defect location can be determined, but device complexity increases
Solution Approach 1:
The patent designs the auxiliary power supply and switch control system to perform multiple functions: it can supply power to the HVIL for normal operation monitoring, perform self-diagnosis of the battery pack, and provide detailed defect location information. By making this single subsystem multi-functional, the patent avoids the need for multiple separate monitoring devices, thereby reducing overall system complexity while maintaining high measurement precision.
Data Source
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AI summary
A battery pack is provided, the battery pack includes: a high voltage interlock loop (HVIL) signal line; and an HVIL state monitoring apparatus comprising an HVIL auxiliary power supply that generates an HVIL auxiliary power signal, and applying the HVIL auxiliary power signal to an input terminal of the at least one high voltage connector while an external controller stops applying an HVIL main power signal to the HVIL signal line.