Battery SOC Estimation via Adaptive Gain Control
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Solution Overview
Problem
Existing pure voltage-type voltaic gauges for battery state of charge (SOC) estimation face inaccuracies during drastic current changes, under varying environmental conditions, and fail to effectively adapt to changes in load, temperature, and battery aging.
Innovation Solution
A method and system that adaptively adjusts the gain for SOC estimation using a gain control engine based on battery current and full charged capacity, combining this with voltage difference calculations to provide accurate SOC changes and next SOC values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If pure voltage-type voltaic gauges are used for SOC estimation, then the method is simple and achieves stable SOC convergence by referencing the OCV curve, but it provides incorrect SOC trends during drastic current changes and cannot adequately respond to changes in load, temperature, battery capacity, and aging degree
Solution Approach 1:
The patent combines voltage-type voltaic gauge methodology with current-type coulomb integrator approach. The system uses both battery voltage (VBAT) and battery current (IBAT) measurements, integrating their advantages: the voltage method provides stable convergence and OCV reference, while the current method provides accurate SOC change calculation during dynamic conditions. This hybrid approach resolves the contradiction by merging the simplicity of voltage-based methods with the precision of current-based methods.
Solution Approach 2:
The patent implements dynamic gain adjustment (K) that adapts to different operating conditions. The gain is not fixed but varies based on battery state, allowing the system to optimize SOC estimation accuracy under different loads, temperatures, and aging conditions. This dynamic adaptation enables the system to maintain high measurement precision while preserving the operational simplicity of the voltage-type approach.
2Stability of the object's composition
If pure voltage-type voltaic gauges are used, then stable SOC convergence is achieved by referencing the OCV curve, but inaccurate SOC rate of change occurs under varying loads, temperatures, battery capacities, or aging conditions
Solution Approach 1:
The system merges voltage-based stable convergence with current-based accurate SOC change calculation. By combining the OCV curve reference (which provides stability) with real-time current measurements (which provide accurate rate of change), the system achieves both stable convergence and accurate SOC rate estimation under varying conditions.
Solution Approach 2:
The patent incorporates feedback mechanisms where the system continuously monitors battery voltage and current, compares them against expected values based on OCV curves, and adjusts the gain parameter accordingly. This feedback loop enables the system to maintain stable convergence while correcting SOC rate of change estimates based on actual measured values, resolving the accuracy issue under varying conditions.
3Device complexity
If pure voltage-type voltaic gauges are used, then the method relies on correlation between battery voltage and SOC, but it fails to effectively cope with variable operating environments including load, temperature, battery capacity, and aging degree
Solution Approach 1:
The patent merges the simple voltage-type approach with the adaptive current-type approach. The system maintains the simplicity of voltage-based methods while adding current measurements and dynamic gain adjustment to provide adaptability to variable operating conditions such as load changes, temperature variations, battery capacity differences, and aging effects.
Solution Approach 2:
The patent dynamically changes the gain parameter (K) based on operating conditions. By adjusting the gain according to battery state, load conditions, and environmental factors, the system adapts to variable operating environments while maintaining the overall simplicity of the voltage-type methodology. This parameter adjustment enables the system to respond effectively to different conditions without complicating the basic algorithm structure.
Data Source
AI summary
The present invention discloses a method of estimating a state of charge (SOC) of a battery and a system thereof. The method of estimating the SOC of the battery includes following steps: calculating a voltage difference (ΔV) using a voltaic gauge based on a battery voltage (VBAT) and an open-circuit voltage (OCV); adaptively adjusting a gain (K) using a gain control engine based on a battery current (IBAT) and a full charged capacity (FCC), wherein the gain (K) is adjusted to generate an adjusted gain (K′); generating a present SOC change (ΔSOC_T) using the voltaic gauge based on the voltage difference (ΔV) and the adjusted gain (K′); and generating a next SOC (SOC_T+1) using an accumulator based on a present SOC (SOC_T) and the present SOC change (ΔSOC_T).