Power Storage Apparatus Current Sensor Error Correction
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Solution Overview
Problem
Existing power storage systems in electric vehicles face challenges in accurately determining the state of charge and correcting current sensor errors, particularly due to differences in characteristics between high-capacity and high-output batteries, which affects the efficiency and accuracy of power distribution and charging processes.
Innovation Solution
A power storage apparatus comprising a first and second storage module with detection units, a charge-discharge circuit, and a control unit that determines the necessity of correction for the detection units based on input and output current values during charging and discharging, using a voltage-current characteristics correlation and step-up/down ratios to correct gain and offset errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If charging and discharging are performed between power storage apparatuses to estimate SOC, then the state of charge can be determined, but current sensor errors and detection inaccuracies occur due to differences in voltage-current characteristics between different battery types
Solution Approach 1:
The control unit performs feedback control by comparing the detected current values from both batteries during charge-discharge operations and correcting detection errors. The system uses the known charge-discharge current relationship as a reference to identify and correct sensor inaccuracies, thereby improving measurement precision while maintaining reliable power distribution.
Solution Approach 2:
The system changes the operating parameters by performing charge-discharge cycles between different battery types (high-capacity and high-output), allowing the control unit to observe voltage-current characteristics under varying conditions. This enables the identification and correction of detection unit errors through parameter comparison and analysis.
2Measurement precision
If multiple detection units are used to monitor current in both storage modules, then current monitoring capability is improved, but detection unit errors and inconsistencies arise
Solution Approach 1:
The control unit implements feedback control by continuously monitoring detection values from both detection units during charge-discharge operations and correcting inconsistencies. By comparing the detected currents against the known charge-discharge relationship, the system identifies and corrects detection errors, preserving accurate information from multiple sensors.
Solution Approach 2:
The system merges the detection capabilities of multiple detection units by using both to monitor the same charge-discharge current. The control unit combines the information from both sensors and applies correction based on the known relationship between battery currents, thereby improving overall monitoring capability while eliminating individual sensor errors.
3Measurement precision
If voltage-current characteristics are used to calculate OCV and estimate SOC, then state of charge estimation is achieved, but detection errors propagate through the calculation process
Solution Approach 1:
The control unit applies feedback control by using the detected current values and voltage-current characteristics to calculate OCV and SOC, then correcting detection errors based on the known charge-discharge current relationship. This feedback mechanism ensures that SOC estimation accuracy is maintained while preventing error propagation through the calculation process.
Solution Approach 2:
The system performs preliminary correction of detection unit errors by analyzing the charge-discharge current relationship before using the detected values for OCV calculation and SOC estimation. By correcting detection inaccuracies in advance, the system prevents error propagation through subsequent calculations, improving both SOC estimation accuracy and system reliability.
Data Source
AI summary
A power storage apparatus includes a first storage module, a second storage module, a charge-discharge circuit, and circuitry. The first storage module includes a first detector to detect first current input to and output from the first capacitor. The second storage module includes a second detector to detect second current input to and output from the second capacitor. The charge-discharge circuit is connected to the first capacitor and the second capacitor to charge and discharge the first capacitor and the second capacitor. The circuitry is configured to control the charge-discharge circuit to control charging and discharging between the first capacitor and the second capacitor. The circuitry is configured to determine whether or not at least one of the first detector and the second detector is to be corrected based on the first current and the second current during charging and discharging between the first capacitor and the second capacitor.