Battery SOC Detection Using Waiting Time Calibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for estimating the State of Charge (SOC) of hybrid vehicle batteries suffer from large errors and low accuracy, leading to potential safety risks due to overcharging or overdischarging, which is not suitable for long-term battery operation.
Innovation Solution
A method and device for detecting SOC that involves determining an initial SOC value based on waiting time, calculating a current SOC value using real-time current measurements, and calibrating the SOC value under specific conditions to reduce detection errors, utilizing a formula SOCn+1=Iw*t*100%/Cb+SOCn, where SOCn is the previous SOC value, Iw is the current, t is the sampling interval, and Cb is the battery capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the open-circuit Amper-Hour integration method is used to calculate SOC, then the calculation is simple, but the measurement precision deteriorates due to error accumulation over time
Solution Approach 1:
The patent introduces a feedback mechanism where the battery voltage is continuously monitored and fed back to correct the SOC value calculated by the Amper-Hour integration method. The correction amount is determined by comparing the calculated SOC with the actual SOC derived from voltage, thereby eliminating error accumulation and improving long-term accuracy without significantly increasing system complexity
Solution Approach 2:
The patent changes the parameter used for SOC calculation from current integration alone to a hybrid approach combining current integration with voltage-based correction. By introducing voltage as an additional parameter for correction, the system maintains the simplicity of the integration method while improving measurement precision through periodic parameter updates
2Measurement precision
If a model-based closed loop algorithm with Kalman filtering is used, then the measurement precision improves, but the device complexity increases due to complex model establishment and parameter calibration
Solution Approach 1:
The patent extracts only the essential correction function from complex Kalman filtering algorithms. Instead of implementing the full model-based closed loop system with state-space models and covariance matrices, it extracts the core idea of using voltage-based SOC as a reference to correct the integration-based SOC, thereby achieving improved accuracy with minimal algorithmic complexity
Solution Approach 2:
The patent uses a simple voltage-SOC correspondence table instead of complex mathematical models. This table can be pre-established through straightforward experiments and used directly for correction without requiring real-time model calculations, effectively replacing expensive and complex computational objects with simple, easy-to-implement alternatives
Data Source
AI summary
Embodiments of the present invention provide a method and a device for detecting SOC of a battery. The method for detecting SOC of a battery includes: determining an initial SOC value of the battery according to a waiting time of the battery; calculating a current SOC value of the battery based on the initial SOC value and a current working current of the battery, denoting as a first SOC value. In embodiments of the present invention, the current of the battery is real-time measured and the SOC value of the battery is calculated by accumulating the current of the battery, in addition, the initial SOC value is calibrated by the waiting time, so that the error of the SOC detection result is reduced, thereby increasing accuracy of the SOC detection result.