Battery Current Sensing Across Mixed-Voltage Packs for Accurate SOC
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing battery management systems face challenges in accurately measuring current values for batteries with different voltage ratings and in communicating current values between sensors and microcontrollers, especially when multiple batteries with varying voltages are used in vehicles.
Innovation Solution
The proposed solution involves a battery management apparatus with a power converter that reduces a first voltage to a second voltage, using first and second current sensors with shunt resistors and interfaces to measure currents in batteries with different voltages, and a processor that estimates state of charge (SOC) values based on these measurements, eliminating the need for complex communication protocols.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single current sensor is used to measure battery current, then the device complexity is reduced, but it becomes impossible to accurately measure currents for batteries with different voltage ratings
Solution Approach 1:
The patent divides the battery system into multiple voltage domains (first voltage domain and second voltage domain) with separate current measurement circuits for each domain. Each battery or group of batteries with similar voltage ratings is assigned to a specific domain with dedicated current sensors and measurement circuits, enabling accurate current measurement for each voltage level while maintaining manageable system complexity through structured segmentation.
2Adaptability or versatility
If batteries with different voltage ratings are used to provide different voltages to electric devices, then the adaptability of the power system is improved, but the difficulty of measuring current values increases
Solution Approach 1:
The patent segments the battery management system into multiple voltage domains, where each domain handles batteries with specific voltage ratings. This segmentation allows the system to maintain high adaptability by supporting multiple voltage levels while reducing measurement difficulty within each domain, as each domain can use measurement circuits optimized for its specific voltage range.
Solution Approach 2:
The patent introduces voltage conversion circuits and domain interface circuits as intermediaries between different voltage domains. These intermediary components enable accurate current measurement in each domain by providing appropriate voltage level adaptation and isolation, allowing the system to handle batteries with different voltage ratings without directly complicating the measurement process in each domain.
3Measurement precision
If battery sensors are simply added to the battery system, then the measurement capability is improved, but communication difficulties arise between sensors and microcontroller unit
Solution Approach 1:
The patent merges the current measurement function and communication function into an integrated battery management module. The current sensors are combined with communication interfaces that can directly communicate with the microcontroller unit through a unified communication bus, eliminating the need for separate communication protocols for each sensor and simplifying the overall system architecture while maintaining accurate current detection capability.
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 approach allows for accurate SOC measurement of batteries with different rated voltages and prevents communication difficulties, enabling efficient battery management and state of health estimation without relying on communication protocols.
Implementation Method 1
a power converter that generates a second voltage by reducing a first voltage output from a power supply
Implementation Method 2
the first current sensor may include a first shunt resistor connected between the first electrode of the first battery and the ground, a first current interface which is configured for measuring the first voltage across the first shunt resistor
Implementation Method 3
the second current sensor may include a second shunt resistor connected between the first electrode of the second battery and the second electrode of the first battery, a second current interface which is configured for measuring the second voltage across the second shunt resistor
Data Source
AI summary
An apparatus for managing a battery and a method thereof includes a power converter that generates a second voltage by reducing a first voltage output from a power supply and output the second voltage, a first current sensor that detects a current of a first battery receiving the second voltage output from the power converter, and a second current sensor that detects a current of a second battery connected in series with the first battery.