Battery Management Device Voltage Fluctuation Diagnosis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing battery managing devices face challenges in immediately measuring cell voltage after diagnosis due to the presence of RC filters, which require a waiting time corresponding to the time constant for the input voltage to match the cell voltage.
Innovation Solution
A battery managing device with a voltage fluctuating unit that causes electrical status variations on the voltage detecting lines, allowing the microcomputer to diagnose the voltage detecting unit's functionality without being constrained by the RC filter's time constant, and a control system that outputs abnormality information to limit power supply based on the diagnosis results.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If an RC filter is connected to the voltage detecting line to remove noise, then noise removal capability is improved, but measurement speed deteriorates due to the time constant delay
Solution Approach 1:
The patent segments the voltage detection system into two independent paths: one path with RC filter for noise removal during normal operation, and another path without RC filter for rapid measurement during diagnosis. This allows both noise filtering and fast measurement capabilities to coexist without interfering with each other.
Solution Approach 2:
The system dynamically switches between different measurement modes based on operational requirements. During normal operation, the filtered voltage is used for accurate capacity calculation. During diagnosis mode, the system switches to unfiltered voltage measurement for immediate response, eliminating the time constant delay.
2Reliability
If pseudo-voltage information is input to diagnose the battery status detection circuit, then diagnostic capability is improved, but immediate cell voltage measurement becomes difficult due to RC filter waiting time
Solution Approach 1:
The system performs preliminary diagnosis by inputting pseudo-voltage information to test the voltage detecting unit before actual cell voltage measurement. This preliminary action validates the detection circuit functionality, ensuring reliable subsequent measurements without requiring waiting time for RC filter discharge.
Solution Approach 2:
The patent extracts the voltage detection function into a separate, independently controllable unit that can be switched between filtered and unfiltered measurement modes. This allows the diagnostic function to operate independently from the normal voltage measurement path, enabling immediate post-diagnosis measurement.
3Reliability
If the voltage detecting unit is diagnosed as abnormal, then system reliability is improved through early detection, but power supply limitation reduces system productivity
Solution Approach 1:
When voltage detecting unit abnormality is detected, the system applies partial power supply limitation rather than complete shutdown. The power management ECU restricts charging current to a safe level that prevents battery damage while maintaining limited vehicle operation capability, thus balancing reliability and productivity.
Solution Approach 2:
The system implements continuous feedback monitoring of voltage detecting unit status through pseudo-voltage input tests. When abnormality is detected, the feedback loop triggers appropriate power supply control actions, dynamically adjusting power supply levels based on the severity and type of abnormality to maintain optimal system performance.
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 immediate cell voltage measurement post-diagnosis and effective power management by mitigating limitations on power supply based on abnormality diagnoses, enhancing the reliability and efficiency of battery management.
Implementation Method 1
an RC filter, which is a nose filter for removal of noise, is connected to a voltage detecting line that is connected between the battery cell and the battery managing device
Data Source
Figure 1
Figure 2
Figure 3(a)~3(b)
AI summary
Cell voltage measurement is executed immediately after termination of diagnosis on a cell voltage detection function. In a battery managing device 10, a voltage detecting unit 140 detects a terminal voltage of each of battery cells 21 and 22. An RC filter 110 is electrically connected to voltage detecting lines L1, L2, and L3, and a status variation causing unit 130 causes an electrical status variation with respect to the voltage detecting lines L1, L2, and L3. A voltage fluctuating unit 120 fluctuates the terminal voltage of the battery cells 21 and 22 in response to the electrical status variation that is caused by the status variation causing unit 130. A microcomputer 150 diagnoses the voltage detecting unit 140 on the basis of a detection result of the terminal voltage of the battery cells 21 and 22 by the voltage detecting unit 140 when the terminal voltage of the battery cells 21 and 22 is fluctuated by the voltage fluctuating unit 120.