Battery Cell Voltage Balancing Across Isolated AFEs
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Solution Overview
Problem
In battery packs with multiple cells connected in series, voltage imbalance occurs due to inconsistent power consumption of independent isolated power supplies, leading to inefficiencies in recycling and management.
Innovation Solution
A voltage balancing system with a balancing module that adjusts the connection of constant value balancing resistors or switch tubes based on current and voltage differences between high-side and low-side analog front ends, using a microcontroller to manage equalization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If two independent AFEs are used to monitor battery cells, then the number of battery cells that can be managed is increased, but voltage imbalance occurs due to inconsistent power consumption of isolated power supplies
Solution Approach 1:
The patent combines the isolated power supply functions of two independent AFEs into a single shared isolated power supply. This merging eliminates the power consumption inconsistency between separate power supplies, thereby resolving the voltage imbalance issue while maintaining the capability to manage multiple battery cells through the coordinated operation of multiple AFEs.
Solution Approach 2:
The isolated power supply is designed to serve multiple AFEs simultaneously, making it a universal power source for the entire battery management system. This multi-functional design allows a single power supply to support multiple monitoring channels, eliminating the need for separate isolated power supplies for each AFE and ensuring consistent voltage levels across all battery cell groups.
2Reliability
If a common isolated power supply is shared by multiple AFEs, then voltage balance is maintained, but the complexity of power supply management increases
Solution Approach 1:
The system implements self-service mechanisms where each AFE autonomously manages its own power consumption and operational state. The microcontroller monitors the operational states of all AFEs and dynamically adjusts the isolated power supply's output, eliminating the need for complex external power supply management circuitry and reducing overall system complexity.
Solution Approach 2:
The system incorporates feedback mechanisms where the microcontroller continuously monitors the operational states of multiple AFEs and the voltage levels of battery cell groups. Based on this feedback, the microcontroller dynamically adjusts the isolated power supply's output to maintain voltage balance, providing intelligent and adaptive power management without increasing hardware complexity.
3Use of energy by moving object
If isolated power supply voltage is reduced to save energy, then power consumption is decreased, but the working current of AFEs increases
Solution Approach 1:
The isolated power supply operates dynamically with adjustable voltage and current output levels. Instead of using a fixed high voltage that wastes energy or a fixed low voltage that increases current, the system dynamically adjusts the power supply parameters based on the real-time operational states of AFEs and battery cell requirements, optimizing the balance between power consumption and working current.
Solution Approach 2:
The system changes the electrical parameters (voltage and current) of the isolated power supply based on operational conditions. By dynamically adjusting these parameters, the system can reduce power consumption during low-activity periods while ensuring sufficient current delivery when AFEs are actively monitoring battery cells, thereby resolving the trade-off between energy savings and current requirements.
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
The system effectively balances voltage across battery cells, reducing power consumption discrepancies and maintaining consistent cell performance.
Implementation Method 1
the balancing module is a constant value balancing resistor connecting with the high-side analog front end or the low-side analog front end
Implementation Method 2
the balancing module connects to the microcontroller and consists of a balancing switch tube and a balancing resistor when a voltage difference between the first voltage and the second voltage is a non-constant value
Data Source
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AI summary
The invention provides a voltage balancing system for balancing controlling of voltage of battery cells including a first set of battery cells and a second set of battery cells connected in series. The system includes a high-side analog front end (AFE) connected to the first set of battery cells, a low-side analog front end (AFE) connected to the second set of battery cells, a microcontroller communicating with the high-side AFE and the low-side AFE, and a communication isolating module interconnecting between the high-side AFE and the microcontroller. The system further includes a balancing module arranged at a back end of the low-side AFE or the high-side AFE to equalize voltages output by the low-side AFE and the high-side AFE. Compared with the prior arts, the system employs a balancing module to balance the voltages of the two sets of battery cells, which can shorten the voltage difference therebetween.