Segmented HVIL Circuit for Selective Traction Machine Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing high-voltage systems in vehicles with multiple electrical machines face challenges in safely disconnecting individual machines without shutting down the entire system due to a single fault, posing risks to maintenance personnel and system functionality.
Innovation Solution
A safety circuit with a primary and secondary high voltage interlock loop (HVIL) system, where each machine has a secondary HVIL circuit controlled by a switch unit that can break the connection and trigger the primary HVIL to ensure safe disconnection, allowing selective machine shutdown.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single high-voltage interlock loop is used to protect the entire system, then system safety is improved, but system availability deteriorates because a single fault shuts down all electrical machines
Solution Approach 1:
The high-voltage interlock loop system is segmented into a primary HVIL circuit connected to the battery and multiple secondary HVIL circuits, each associated with a specific electrical machine. This segmentation allows individual machines to be isolated without affecting the entire system, resolving the contradiction between safety and availability.
2Object-affected harmful factors
If the entire power system is shut down due to a fault in one electrical machine, then safety is improved, but system functionality deteriorates because critical machines cannot operate
Solution Approach 1:
The system uses separate secondary HVIL circuits for each electrical machine, enabling selective disconnection of faulty machines while maintaining operation of critical machines. This resolves the contradiction between hazard protection and system functionality.
Solution Approach 2:
The secondary HVIL circuits act as intermediaries between the primary HVIL circuit and individual electrical machines. They enable selective fault isolation without requiring complete system shutdown, maintaining both safety and functionality.
3Ease of operation
If manual shutdown procedures are used for high-voltage systems, then ease of operation is improved, but safety deteriorates due to potential hazards during maintenance
Solution Approach 1:
The HVIL system provides automatic safety functions that complement manual operations. The interlock circuits automatically detect faults and disconnect machines, providing self-service safety protection while maintaining ease of manual control for normal operations.
Data Source
AI summary
A safety circuit for a high-voltage electrical traction system comprising a plurality of electric machines. The safety circuit comprises a primary high voltage interlock loop (HVIL) circuit configured to be connected to a battery and for each of the plurality of electric machines, a secondary high voltage interlock loop (HVIL) circuit, wherein each secondary HVIL-circuit is controlled by a corresponding switch unit configured to break the secondary HVIL-circuit if a fault in a corresponding electric machine is detected, and wherein the switch unit comprises a trigger device configured to break the primary HVIL-circuit if the switch unit is opened.