Vehicle Isolation Testing via Simulated Leakage Path
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The development of hybrid and electric vehicles faces challenges in testing the isolation between high and low voltage electrical systems, particularly due to the unavailability of suitable testing environments and the difficulty in managing hardware or software changes during the development cycle with limited resources.
Innovation Solution
A test system comprising a communication interface, impedances, and a controller that electrically connects a selected impedance between a traction battery and a vehicle subsystem to create a leakage path, allowing for diagnostic status output based on leakage current and signal feedback, enabling early validation and testing of isolation monitoring features.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If isolation testing is performed using prototype traction battery packs or prototype vehicles, then testing accuracy and reliability are improved, but device complexity and resource requirements increase
Solution Approach 1:
The patent creates a simplified test environment that copies only the essential elements needed for isolation testing. Instead of requiring complete prototype battery packs or vehicles, the system uses a controller that simulates the high-voltage system and subsystem interactions, allowing accurate isolation monitoring validation without the complexity of full prototypes.
Solution Approach 2:
The invention extracts the critical testing function from the complex prototype system. By isolating just the controller and creating a minimal test environment with simulated high-voltage connections and subsystems, the system removes unnecessary complexity while retaining the core capability to validate isolation monitoring functionality.
2Device complexity
If testing is delayed until prototype battery packs or vehicles are available, then device complexity is reduced, but loss of time in the development cycle increases
Solution Approach 1:
The patent enables preliminary isolation testing to be performed before prototype battery packs or vehicles are available. The test environment is set up in advance using a controller that can simulate high-voltage system behavior, allowing development teams to validate isolation monitoring functionality early in the development cycle and proceed with hardware/software changes without waiting for physical prototypes.
3Adaptability or versatility
If hardware or software changes are made during vehicle development, then adaptability is improved, but the difficulty of detecting and measuring isolation faults increases
Solution Approach 1:
The patent implements a feedback mechanism where the controller continuously monitors the simulated high-voltage system and subsystem interactions. When hardware or software changes are made to the isolation monitoring system, the controller can immediately test these changes by simulating various isolation fault conditions and observing the diagnostic responses, providing real-time feedback on whether the changes work as intended.
Solution Approach 2:
The test environment is designed to be self-contained and easily reconfigurable. The controller automatically manages the simulation of high-voltage systems and subsystems, allowing rapid iteration of hardware and software changes without requiring external testing infrastructure. This self-service capability maintains adaptability while simplifying fault detection through automated testing protocols.
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
Enables effective evaluation and validation of isolation monitoring in vehicle electrical systems without the need for prototype traction battery packs or vehicles, facilitating early detection and management of isolation faults during development.
Implementation Method 1
The controller is programmed to electrically connect a selected one of the impedances between a traction battery of the vehicle and a subsystem of the vehicle. The connection creates a leakage path between the traction battery and the subsystem.
Implementation Method 2
A test system for a vehicle includes a current sensor, a plurality of impedances, a communication interface and a controller. The controller is programmed respond to isolation fault feedback from the communication interface.
Data Source
AI summary
An isolation test system for a vehicle includes a communication interface, a current sensor, a plurality of impedances and a controller. The controller is programmed to electrically connect a selected one of the impedances between a traction battery of the vehicle and a low voltage subsystem of the vehicle. The connection creates a leakage path between the traction battery and the subsystem. The controller is further programmed to output a diagnostic status based on a current associated with the leakage path and a signal received via a communication interface indicative of an isolation fault between the battery and subsystem.