Electricity Storage Device Testing via Current Convergence
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Solution Overview
Problem
Existing methods for determining the defectiveness of electricity storage devices are time-consuming and lack accuracy due to reliance on voltage measurement, which is affected by contact variations and poor accuracy.
Innovation Solution
A testing method that measures current through a closed circuit formed by connecting an external power source to the electricity storage device, with feedback-controlled output voltage adjustments to accelerate convergence and reduce divergence, allowing for quick and accurate determination of self-discharge levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If voltage measurement is used to determine battery defectiveness, then measurement can be performed with existing equipment, but the measurement time is long and accuracy is poor due to contact position variations
Solution Approach 1:
The patent replaces voltage measurement with current measurement. Instead of measuring voltage at battery terminals (which suffers from contact resistance and position variations), the invention measures current flowing through the battery using a closed circuit with a power source. This substitution of measurement method eliminates the harmful effects of contact variations while providing more accurate and faster defectiveness determination.
2Measurement precision
If let-stand time is extended to achieve significant voltage decrease for defect determination, then measurement accuracy improves, but processing time increases significantly
Solution Approach 1:
The patent replaces the time-consuming voltage-based let-stand method with a current-based measurement method. By measuring current in a closed circuit formed by connecting a power source to the battery, the system can determine defectiveness immediately without requiring extended stand times. This substitution enables both high accuracy and fast processing, resolving the contradiction between measurement precision and productivity.
3Measurement precision
If current measurement is used instead of voltage measurement, then measurement accuracy improves and time is reduced, but additional circuit components and control mechanisms are required
Solution Approach 1:
The patent introduces a power source and closed circuit as intermediary elements to enable current measurement. The power source connects to the battery terminals to form a closed circuit, allowing current flow that can be measured accurately. This intermediary setup provides a controlled environment for measurement that simplifies the overall system while improving accuracy, as the current measurement is不受接触位置影响 (not affected by contact position).
Solution Approach 2:
The patent implements feedback control by monitoring the current measurement results and using them to determine battery defectiveness. The system measures current, compares it against threshold values, and automatically determines whether the battery is defective or normal. This feedback mechanism streamlines the testing process and reduces the need for complex manual evaluation procedures.
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 method enables rapid and precise identification of defective or non-defective electricity storage devices by measuring current convergence, reducing processing time and minimizing errors associated with voltage measurement.
Implementation Method 1
applying to the closed circuit a voltage in the opposite direction from the direction of voltage of the electricity storage device by the external power source
Implementation Method 2
measuring the value of the current flowing through the closed circuit
Implementation Method 3
the output voltage of the external power source is changed according to the calculated voltage in the feedback computing step
Data Source
AI summary
Provided is an electricity storage device testing method including: building a closed circuit by connecting an external power source to a charged electricity storage device such that the direction of voltage of the external power source is opposite from that of the electricity storage device; measuring a circuit current while applying to the closed circuit a voltage in an opposite direction from a voltage of the electricity storage device by the external power source; calculating a voltage to be output by the external power source, based on the value of the circuit current measured and a resistance value of the closed circuit. The output voltage of the external power source is changed according to a result of the calculation. A time interval at which the calculation is set to be shorter at an early stage and longer at a late stage of the measuring.