Floating Capacitor Voltage Measurement Circuit
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Solution Overview
Problem
Conventional battery cell voltage measuring apparatuses require complex circuit structures due to the need for differential amplifiers and polarity inversion circuits when measuring the voltage of multiple cells, increasing component count and complexity.
Innovation Solution
A battery cell voltage measuring apparatus using multiple floating capacitors and switching units that can be switched between charge, hold, and measurement modes, eliminating the need for differential amplifiers and polarity inversion circuits by applying cell voltages between a reference potential and a common cell voltage measuring line.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single differential amplifier is used to measure the voltage of multiple cells, then the measurement function is achieved, but the circuit structure becomes complicated due to the need for polarity inversion circuits
Solution Approach 1:
The patent divides the voltage measurement function into multiple independent measurement paths, with each path having its own differential amplifier. This segmentation eliminates the need for a single complex amplifier to handle multiple cells with different polarities, as each amplifier only needs to handle one cell's voltage measurement independently.
Solution Approach 2:
Instead of using a single differential amplifier with polarity inversion circuits to handle multiple cells, the patent inverts the approach by using multiple differential amplifiers without polarity inversion circuits. Each amplifier directly measures one cell's voltage, reversing the conventional architecture to simplify the overall circuit.
2Device complexity
If extra switches per cell are used to avoid polarity inversion circuits, then the circuit structure is simplified, but the component count increases
Solution Approach 1:
The patent merges the functions of multiple differential amplifiers into a unified measurement system where all amplifiers share common reference voltage lines and are coordinated by a single controller. This combining approach reduces the need for excessive individual components while maintaining the simplified circuit structure.
Solution Approach 2:
Each differential amplifier is designed as a universal measurement unit that can measure any cell's voltage when properly configured. The amplifiers share common reference voltage generation circuits and control logic, making them multi-functional components that reduce the overall component count compared to having completely separate measurement circuits for each cell.
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 simplifies the circuit configuration, reduces the number of switch devices required, and enables direct voltage measurement of multiple cells without differential amplifiers or polarity inversion circuits, enhancing the efficiency and reliability of battery management systems.
Implementation Method 1
a plurality of floating capacitors provided corresponding to a plurality of cells contained in a battery pack
Data Source
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AI summary
Disclosed is a battery cell voltage measuring apparatus and method. The battery cell voltage measuring apparatus comprises a plurality of floating capacitors provided corresponding to a plurality of cells contained in a battery pack; a plurality of switching units provided corresponding to each cell of the battery pack and switchable into a charge mode or a measurement mode; and a cell voltage detector for measuring the voltage of each cell by switching each switching unit into a charge mode to charge the voltage of each cell on each corresponding floating capacitor and time-differentially switching each switching unit into a measurement mode to apply the cell voltage charged on the floating capacitor between a reference potential and a common cell voltage measuring line.