Power Supply Device Voltage Detection Line Disconnection
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Solution Overview
Problem
In power supply devices with serially connected battery cells, detecting disconnection of voltage detection lines is challenging due to unbalanced consumption currents, leading to potential over-charging or over-discharging of battery cells, which can cause deterioration and safety issues.
Innovation Solution
Incorporating an unbalance resistor in at least one battery block to increase power consumption, ensuring currents flow in all voltage detection lines, and using a disconnection detecting circuit to identify voltage deviations, allowing for reliable detection of voltage detection line disconnections and cell voltage monitoring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If voltage detection lines are used to monitor battery cell voltages in series-connected battery packs, then battery cell over-charging and over-discharging can be prevented, but disconnection of voltage detection lines cannot be reliably detected when consumption currents are unbalanced
Solution Approach 1:
The patent introduces an unbalance resistor as an intermediary component connected in parallel to one of the battery blocks. This resistor creates a controlled current imbalance that ensures current always flows through all voltage detection lines, enabling reliable disconnection detection without requiring complex additional detection circuits. The resistor acts as a mediator that transforms the unbalanced consumption current issue into a beneficial condition for detection.
Solution Approach 2:
The patent changes the electrical parameter (current flow) in the voltage detection lines by introducing the unbalance resistor. This parameter change ensures that current flows through all detection lines regardless of the natural current imbalances caused by unequal power consumption of voltage detecting circuits, thereby enabling reliable disconnection detection.
2Reliability
If unbalance resistors are added to battery blocks to ensure current flow in voltage detection lines, then disconnection detection reliability is improved, but power consumption of the battery block increases
Solution Approach 1:
The patent applies partial action by introducing the unbalance resistor only in specific battery blocks where voltage detection line disconnection cannot be detected, rather than in all battery blocks. This selective application minimizes the overall power consumption impact while achieving the detection reliability improvement where it is most needed.
Solution Approach 2:
The unbalance resistor creates a copied or simulated current flow path that mimics the behavior of a properly functioning voltage detection line. By creating this artificial current path, the system can detect actual disconnections without requiring significant additional power consumption, as the resistor value can be optimized to draw minimal current.
3Productivity
If DC-DC converters with unbalanced consumption currents are used to power voltage detecting circuits, then device efficiency is improved, but voltage detection line disconnection cannot be detected
Solution Approach 1:
The patent converts the harmful effect of unbalanced consumption currents into a beneficial condition for detection. By intentionally introducing an unbalance resistor that creates a known current imbalance, the system transforms the problematic current unbalance into a reliable indicator for detecting voltage detection line disconnections. The natural current differences caused by efficient but unbalanced DC-DC converters are harnessed rather than eliminated.
Data Source
AI summary
A power supply device includes battery units. Each unit includes a battery block, a voltage detector, a power supply circuit, and a disconnection detector. The block includes serially-connected battery cells. The voltage detector detects the cell voltages through voltage detection lines. The power supply circuit supplies power from the block to the voltage detector. The voltage detector is powered by electric power from the block. The disconnection detector detects disconnection of the lines based on the detected cell voltages. An unbalance resistor is connected to one of the blocks to increase power consumption of this block. Thus, a current flows in the line that is connected to a node between this block and an adjacent block connected next to this block.