Battery BMS Node Isolation for Arc Fault Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional battery management systems are unable to identify and extinguish arc faults, and existing isolation switches do not protect good batteries from failed ones, leading to potential fires and the need to safely discharge unsafe batteries.
Innovation Solution
A hierarchical arc fault detection method and safe battery management system that can identify electrical arcs, operate in multiple modes for safety and maintenance, and prevent short circuit current flow, including using bidirectional DC-DC converters and isolation switches to safely isolate batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional isolation switches are used to isolate failed batteries, then battery isolation can be achieved, but good batteries cannot be protected from failed ones and arc faults cannot be detected
Solution Approach 1:
The system divides the battery management function into multiple independent BMS nodes, each capable of detecting arc faults and controlling isolation switches for its associated battery. This segmentation allows individual batteries to be isolated without affecting the entire system, and enables distributed arc detection across all batteries simultaneously.
Solution Approach 2:
The patent introduces bidirectional DC-DC converters as intermediary devices between batteries and the load. These converters include isolation switches that can disconnect failed batteries from the system while maintaining system operation. The converters act as mediators that protect both good batteries from failed ones and prevent arc faults from propagating.
2Object-affected harmful factors
If batteries are isolated to prevent fires, then safety is improved, but system productivity decreases due to loss of battery capacity
Solution Approach 1:
The system dynamically adjusts the number of active batteries based on their health status and the system's power requirements. When a battery fails, only that specific battery is isolated while others continue operating. The bidirectional DC-DC converters dynamically control isolation switches to maintain optimal system performance while ensuring safety.
Solution Approach 2:
The patent changes the operational parameters of batteries from all-or-nothing operation to selective operation. By monitoring individual battery parameters (voltage, current, temperature) and using bidirectional DC-DC converters, the system can adjust which batteries are active and which are isolated, optimizing both safety and productivity continuously.
3Object-affected harmful factors
If arc fault detection is implemented, then system safety is improved, but device complexity increases due to additional monitoring requirements
Solution Approach 1:
Each BMS node performs self-diagnosis by monitoring its own battery and communicating with neighboring nodes. The distributed architecture allows each node to detect arc faults in its associated battery independently, eliminating the need for a complex centralized monitoring system. The system serves itself through decentralized intelligence.
Solution Approach 2:
The bidirectional DC-DC converters serve multiple functions: power conversion, battery isolation, and arc fault detection. By combining these functions into a single device, the patent reduces overall system complexity compared to having separate dedicated components for each function. The converters are universal devices that handle multiple tasks simultaneously.
Data Source
AI summary
A battery stack includes a plurality of battery management system (BMS) nodes and a controller. Each BMS node includes a battery, an isolation switch configured to selectably isolate the battery of the BMS node from the batteries of the other BMS nodes, and a bypass switch configured to selectably provide a path for electrical current flowing through the battery stack to bypass the battery of the BMS node. The batteries of the BMS nodes are electrically coupled in series. The controller is configured to control the isolation switch and the bypass switch of each BMS node such that the battery of each BMS node can be individually connected to and disconnected from an electrical power source/sink.