Battery State Estimation Using Low Pass Filter Noise Removal
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Solution Overview
Problem
Existing battery state estimation methods suffer from insufficient accuracy due to observation noise in current and terminal voltage measurements, which affects the identification of secondary battery parameters.
Innovation Solution
A battery state estimation device and method that employs a low pass filter to treat terminal voltage measurements, removing observation noise and improving parameter identification accuracy by converging the difference between measured and estimated terminal voltages to zero.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current measured value and terminal voltage measured value are used directly for parameter identification, then the identification process is simple, but the accuracy of parameter identification is insufficient due to observation noise
Solution Approach 1:
A low pass filter is introduced as an intermediary component between the measurement devices and the parameter identification algorithm. The filter processes the raw current and voltage measurements to remove observation noise before the data is used for parameter identification, thereby improving accuracy without directly modifying the identification algorithm itself
Solution Approach 2:
The harmful observation noise is extracted and removed from the measurement signals through filter treatment. By separating the useful signal from the noise component, the patent applies only the clean, useful information to the parameter identification process, improving the reliability of the identification results
2Measurement precision
If filter treatment is applied to remove observation noise, then parameter identification accuracy is improved, but the device complexity and processing time increase
Solution Approach 1:
The patent optimizes the filter parameters (such as cutoff frequency and filter order) to achieve the best balance between noise removal effectiveness and processing speed. By carefully selecting filter parameters, the system removes sufficient observation noise while minimizing the computational time required for filtering operations
Data Source
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AI summary
An object of the present invention is to provide a battery state estimation device and a battery state estimation method which identify parameter of a secondary battery with high accuracy. A current and a terminal voltage of secondary battery are detected, then by using the current measured value and terminal voltage measured value thus detected, the terminal voltage of secondary battery based on predetermined battery model is estimated, and the parameter of the secondary battery is identified such that a difference between terminal voltage measured value and voltage estimated value is converged to zero. In the identifying of parameter of secondary battery, the terminal voltage measured value and terminal voltage estimated value are subjected to filter treatment by low pass filter having a common high frequency breaking characteristic and the terminal voltage measured value and terminal voltage estimated value subjected to the filter treatment are used.