Battery Current Measurement Using Shunt and Test Pattern Verification
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Solution Overview
Problem
Current electric current measurement systems in battery systems face challenges such as high costs, sensitivity to magnetic fields, and complexity in wiring harnesses, particularly due to the use of Hall sensors and the need for multiple control components, which complicates safety integrity levels and increases development efforts.
Innovation Solution
An electric current measuring arrangement that utilizes a first control unit with a high-safety-level microcontroller to generate and verify a test pattern signal, transmitted through a communication line to a second control unit, which receives and amplifies the signal, allowing for verification of current measurements without relying on expensive Hall sensors and reducing the safety level requirements for the second microcontroller, thereby reducing costs and complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If Hall sensors are used for current measurement, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the current measurement function from the complex Hall sensor system and implements it using a simple shunt resistor. The shunt resistor is integrated into the existing battery management system architecture, eliminating the need for separate Hall sensor modules and their associated complex wiring harnesses, while maintaining adequate measurement precision for battery management applications.
Solution Approach 2:
The patent replaces expensive Hall sensors with inexpensive shunt resistors. The shunt resistor is a simple, low-cost component that can be easily integrated into the battery management system, significantly reducing both component cost and wiring complexity while providing sufficient measurement capability for the application.
2Reliability
If multiple control components are used, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent merges the current measurement and verification functions into a unified control component architecture. The first microcontroller generates test patterns and the second microcontroller verifies them, but both are integrated into the existing battery management control structure, reducing the need for separate safety components while maintaining high reliability through functional distribution.
Solution Approach 2:
The patent implements a feedback mechanism where test patterns generated by the first microcontroller are verified by the second microcontroller, and the verification results are used to confirm the operational status of the shunt resistor and amplifier. This closed-loop feedback system ensures high reliability without requiring additional complex safety components.
3Device complexity
If shunt resistor with amplifier is used, then device complexity is reduced, but sensitivity to magnetic fields increases
Solution Approach 1:
The patent uses a test pattern copying approach where the first microcontroller generates a known test signal pattern that is copied through the shunt resistor and amplifier to the second microcontroller for verification. This allows the system to characterize and compensate for any magnetic field interference by comparing the expected test pattern with the actual received pattern, thereby reducing the impact of magnetic sensitivity.
4Reliability
If verification system is implemented, then reliability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent implements verification using test patterns that use only partial signal ranges and tolerate certain levels of transmission imperfection. The verification system checks for the presence and basic characteristics of the test signal rather than requiring perfect signal fidelity, thereby reducing manufacturing precision requirements while still providing reliable verification of the measurement system's operational status.
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
This solution provides a cost-effective and safe method for verifying current measurements, reducing magnetic interference and wiring complexity, while maintaining a high safety level through the use of a high-safety-level microcontroller for critical tasks, thus addressing the limitations of existing systems.
Implementation Method 1
an amplifier electrically interconnected between the second microcontroller and terminals of the shunt resistor for current measurement
Data Source
AI summary
An electric current measuring arrangement includes: a first control unit including a first microcontroller; a second control unit including: a second microcontroller; an amplifier electrically interconnected between the second microcontroller and terminals of a shunt resistor for current measurement; and a node interconnected between one of the terminals of the shunt resistor and the amplifier; a communication line communicatively connecting the first control unit and the second control unit. The first microcontroller is configured to generate a test pattern signal, and to transmit the test pattern signal to the second control unit through the communication line, the second control unit is configured to transmit the test pattern signal to the node, the second microcontroller is configured to receive a measuring signal through the amplifier, and the first microcontroller is configured to receive the measuring signal, compare the measuring signal with the test pattern signal, and verify the current measurement.