Battery Management Charge Transfer Measurement with Unsynchronized Clocks
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Solution Overview
Problem
Existing battery management systems face challenges in accurately determining charge transfer due to clock signal drift, clock accuracy differences between components, and inefficient communication protocols, which affect the precision and reliability of charge transfer measurements.
Innovation Solution
The system employs an analog front end (AFE) circuit with an unsynchronized clock signal to measure average current values, offloading timing calculations to a host microcontroller with a more accurate clock, and using message-based communication to enhance robustness, while incorporating programmable gain amplifiers and automatic gain control to improve measurement accuracy and handle clock drift.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the AFE circuit uses its own unsynchronized clock signal for timing, then the device complexity and power consumption are reduced, but the measurement precision and reliability of charge transfer calculations deteriorate due to clock drift
Solution Approach 1:
The patent introduces a time value determination mechanism as an intermediary that bridges the unsynchronized AFE clock and the synchronized host microcontroller clock. The AFE circuit determines time values based on its unsynchronized clock for controlling current measurement operations, while the host microcontroller determines time values based on its synchronized clock for accurate charge transfer calculations. This intermediary approach allows each component to operate independently with its own clock while maintaining overall system accuracy through coordinated time value determination.
2Ease of operation
If the AFE circuit operates independently with its own clock signal, then the ease of operation and modularity are improved, but the reliability of charge transfer determination deteriorates due to clock accuracy differences
Solution Approach 1:
The patent segments the timing functions between two independent components: the AFE circuit handles local timing for current measurement operations using its own unsynchronized clock, while the host microcontroller handles system-level timing for charge transfer calculations using its synchronized clock. This segmentation allows each component to operate independently with its own clock signal, improving modularity and ease of operation, while the host microcontroller ensures overall system reliability by coordinating time values from both clocks.
3Device complexity
If the host microcontroller determines both time values and average current values, then the device complexity is reduced, but the productivity and processing efficiency deteriorate
Solution Approach 1:
The patent segments the processing tasks between the AFE circuit and the host microcontroller. The AFE circuit determines average current values by processing current measurements from its unsynchronized clock perspective, while the host microcontroller determines time values based on its synchronized clock and performs the final charge transfer calculations. This segmentation improves productivity by distributing computational workload, allowing each component to focus on specific tasks optimized for its capabilities.
Solution Approach 2:
The patent introduces time value determination as an intermediary function that facilitates efficient collaboration between the AFE circuit and host microcontroller. The AFE circuit provides average current values with its unsynchronized timing, while the host microcontroller provides synchronized time values. This intermediary time value determination mechanism enables efficient data exchange and processing, improving overall system productivity without requiring both components to perform all calculations.
Data Source
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AI summary
A battery management system can include a host microcontroller, which can be operated in accordance with a first clock signal, and an analog front end (AFE) circuit, where the AFE circuit can be operated in accordance with a second clock signal that can be unsynchronized with the first clock signal. The AFE circuit can include an input which can be configured to receive a representation of a battery current associated with one or more cells in a battery system. The AFE circuit can also include current measurement circuitry, included in or coupled to the AFE circuit, which can be configured to generate an average current value representative of an average of the battery current for a specified time period. The host microcontroller can be configured to determine a time value representative of a duration of the specified time period, and determine, based on the indication of the average current value, a current transfer value of the battery current during the specified time period.