BMS Semiconductor Leakage Current Detection Circuit
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Solution Overview
Problem
Existing Battery Management System (BMS) semiconductor devices face complexity in detecting leakage current due to the need for Analog to Digital Converters (ADC) or Multiplexers (MUX), which complicates circuit configuration and consumes battery power, especially in high-voltage battery systems used in electric vehicles.
Innovation Solution
Incorporating a simple comparator circuit in the balancing terminal of the BMS semiconductor device to detect leakage current without the need for a separate ADC, using a leakage current determining unit that sets variable threshold values based on voltage differences between sensing and balancing terminals to identify overvoltage or low-voltage conditions, thereby determining leakage current cases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate ADC or MUX is used to detect leakage current at the balancing terminal, then leakage current detection capability is improved, but device complexity increases
Solution Approach 1:
The ADC is configured to multiplex between two functions: detecting voltage differences between sensing terminals for normal battery monitoring, and detecting voltage at the balancing terminal for leakage current detection. This allows one ADC to serve multiple purposes, eliminating the need for separate detection circuits and reducing overall device complexity while maintaining full leakage current detection capability
2Reliability
If a separate ADC or MUX is used to detect leakage current, then leakage current detection capability is improved, but power consumption increases
Solution Approach 1:
The ADC operates in a time-multiplexed manner, alternating between sensing terminal voltage difference detection and balancing terminal leakage current detection. By sharing the ADC resource between these two detection tasks rather than operating continuously or having separate dedicated ADCs, the power consumption is significantly reduced while maintaining both detection capabilities
3Device complexity
If the ADC is used for both sensing terminal voltage difference detection and balancing terminal leakage current detection, then device complexity is reduced, but measurement precision may be affected
Solution Approach 1:
The system implements periodic time-multiplexed measurement cycles where the ADC alternates between measuring voltage differences at sensing terminals and measuring voltage at the balancing terminal. This periodic switching allows the single ADC to accurately perform both measurement functions by dedicating specific time slots to each measurement type, maintaining precision while reducing hardware complexity
Solution Approach 2:
The control logic pre-configures the ADC for specific measurement tasks based on detection needs. Before each measurement cycle, the system determines whether sensing terminal monitoring or balancing terminal leakage detection is required, and accordingly configures the ADC connections and measurement parameters in advance, ensuring accurate measurements are taken with the appropriate circuit configuration
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 detection of leakage currents with a simplified circuit configuration, reducing power consumption and facilitating quick failure identification and repair in high-voltage battery systems.
Implementation Method 1
a comparator configured to compare a voltage of a balancing terminal connected to a positive voltage terminal of a battery cell and a voltage of a lower sensing terminal connected to a negative voltage terminal of the battery cell
Implementation Method 2
an ADC connected to the upper sensing terminal and the lower sensing terminal and configured to sense a voltage difference between the upper sensing terminal connected to the positive voltage terminal of the battery cell and the lower sensing terminal
Data Source
AI summary
A Battery Management System (BMS) semiconductor device having a leakage current detection function, may include: a comparator configured to compare a voltage of a balancing terminal connected to a positive voltage terminal of a battery cell and a voltage of a lower sensing terminal connected to a negative voltage terminal of the battery cell and output a result of the comparing; an ADC connected to the upper sensing terminal and the lower sensing terminal and configured to sense a voltage difference between the upper sensing terminal connected to the positive voltage terminal of the battery cell and the lower sensing terminal; and a leakage current determining unit connected to the ADC and the comparator and configured to set a variable threshold value according to the difference value sensed by the ADC and determine whether a leakage current is generated by using the result of the comparing in the comparator and the variable threshold value.