Battery Assembly Controller Voltage Equalization
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Solution Overview
Problem
Battery assemblies with series-connected secondary batteries face inefficiencies due to manufacturing and temperature differences, leading to unequal terminal voltages, which existing controllers fail to accurately measure and equalize.
Innovation Solution
A battery assembly controller with a monitoring circuit directly connected to the positive and negative electrodes of secondary batteries, using a discharge circuit to selectively reduce terminal voltages and a low-pass filter for accurate voltage measurement, allowing for precise equalization of secondary battery voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a resistor is placed on a path shared by discharge circuit and monitoring circuit, then discharge current can flow through the circuit, but voltage drop at the resistor causes inaccurate voltage measurement by the monitoring circuit
Solution Approach 1:
The patent divides the circuit into separate paths: one for discharge current and another for voltage monitoring. The monitoring circuit has its own dedicated path from the battery terminals that does not include the discharge resistor, while the discharge circuit has a separate path through the resistor. This segmentation allows both functions to operate simultaneously without interference.
Solution Approach 2:
The patent introduces switching elements (transistors) as intermediaries to control the flow paths. These switches can selectively connect or disconnect the monitoring circuit from the battery terminals independently of the discharge circuit, allowing the monitoring function to operate without being affected by the discharge resistor's voltage drop.
2Productivity
If existing battery assembly controllers are used, then discharge function is provided, but accurate voltage measurement and equalization of secondary batteries cannot be achieved
Solution Approach 1:
The monitoring circuit is segmented into independent measurement paths for each battery cell, with each path having its own switching element. This allows individual voltage measurement of each cell without interference from discharge operations, enabling accurate voltage equalization control.
Solution Approach 2:
The patent implements a feedback mechanism where the monitoring circuit continuously measures individual battery voltages, and this information is used to control the discharge circuit's switching elements. The system adjusts which cells are discharged based on their voltage levels, creating a closed-loop control system that achieves accurate voltage equalization across all cells.
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
Ensures accurate measurement and equalization of secondary battery voltages, reducing costs by minimizing the number of voltage detection components and preventing breakdown of cell balancing switches.
Implementation Method 1
a low-pass filter for accurate voltage measurement
Data Source
AI summary
A battery assembly controller controls terminal voltages of a plurality of series-connected secondary batteries to be equal. The controller includes a discharge circuit selectively reducing the terminal voltages of the secondary batteries; and a monitoring circuit directly connected to positive and negative electrodes of the secondary batteries to monitor the terminal voltages of the secondary batteries.