Battery Management Device AC-Coupling for Service Disconnect Switch
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In assembled batteries, the service disconnect switch interrupts communication between adjacent integrated circuits, preventing them from performing cell voltage measurement and balancing operations when opened, due to insulation of their grounds.
Innovation Solution
A battery management device with a signal transmission path and a connection circuit that AC-couples the integrated circuits through capacitors, allowing communication and operation even when the service disconnect switch is opened.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the service disconnect switch is opened to interrupt the current path and ensure operator safety, then operator safety is improved, but communication between adjacent integrated circuits is interrupted and they cannot perform cell voltage measurement and balancing operations
Solution Approach 1:
The battery system is divided into first and second battery cell groups separated by the service disconnect switch, with each group having its own integrated circuit. The communication path is segmented to allow independent operation of each integrated circuit while maintaining safety isolation through the switch.
Solution Approach 2:
A capacitor is introduced as an intermediary component in the communication path between the first and second integrated circuits. This capacitor enables AC coupling that allows signal transmission while blocking DC current, maintaining ground insulation when the service disconnect switch is open, thus enabling communication without compromising safety isolation.
2Object-affected harmful factors
If grounds of adjacent integrated circuits are insulated from each other when the service disconnect switch is opened, then safety isolation is improved, but signal transmission between integrated circuits is blocked
Solution Approach 1:
The communication signal parameters are changed from DC to AC coupling through the capacitor. This parameter change allows the signal to pass through the capacitor while maintaining ground insulation, enabling communication without requiring a direct DC connection that would compromise safety isolation.
Solution Approach 2:
The capacitor serves as an intermediary that transfers AC communication signals between the two integrated circuits while maintaining electrical isolation of the grounds. This intermediary component enables signal transmission without creating a direct electrical connection that would defeat the purpose of ground insulation for safety.
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 integrated circuits to operate and perform cell voltage measurement and balancing even when the service disconnect switch is opened, ensuring safe and effective battery management.
Implementation Method 1
a connection circuit that AC-couples a coupling target terminal of the first integrated circuit, which is electrically connected to any of the battery cells of the first battery cell group, to a coupling target terminal of the second integrated circuit, which is electrically connected to any of the battery cells of the second battery cell group, through a capacitor
Data Source
AI summary
Even when a service disconnect switch is opened, an integrated circuit connected to single battery cells are operated. The cell controller is provided with: the integrated circuits; a signal transmission path through which a signal is transmitted between the integrated circuits via the capacitors; and the connection circuit. The first integrated circuit is provided corresponding to the first cell group electrically connected to one side of the SD-SW, and the second integrated circuit is provided corresponding to the second cell group electrically connected to one side of the SD-SW. The connection circuit AC-couples the ground terminal GND of the first integrated circuit to the ground terminal GND of the second integrated circuit through the capacitor.