Energy Storage State Estimation via Probability Distribution Integration
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Solution Overview
Problem
Existing methods for estimating the state of health (SOH) of energy storage devices suffer from decreasing accuracy over time due to estimation errors and are challenging to implement in real-time, especially in complex charge-discharge patterns and when noise affects sensor measurements.
Innovation Solution
A state estimation method that treats the degradation of energy storage devices as a probability system, using both historical data and real-time characteristic values to derive a robust SOH estimation by integrating first and second probability distributions, allowing for real-time monitoring without relying solely on continuous sensor data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If SOH is estimated sequentially based on history data in real-time operation, then real-time monitoring is achieved, but estimation errors accumulate and accuracy decreases over time
Solution Approach 1:
The patent implements feedback by periodically measuring the actual SOH and using it to correct the estimated SOH values. The correction amount is calculated based on the difference between actual and estimated SOH, and this correction is applied to subsequent estimates to prevent error accumulation while maintaining real-time monitoring capability
Solution Approach 2:
The patent performs preliminary SOH estimation using history data before actual SOH measurement is available. This preliminary estimate provides continuous real-time monitoring, and when actual measurement becomes available, it serves to correct and refine the preliminary estimates, combining the benefits of continuous monitoring with periodic accuracy verification
2Measurement precision
If SOH is estimated based on characteristic value measurement, then estimation errors do not accumulate, but the energy storage system must stop normal operation and special operations are required
Solution Approach 1:
The patent creates a virtual model of SOH estimation based on history data that replicates the functionality of actual SOH measurement. This virtual estimate allows the system to continue normal operation while providing SOH information, and the virtual model is periodically refined using actual measurements to maintain accuracy without requiring system shutdown
3Loss of time
If SOH is estimated based on continuous sensor measurements, then real-time SOH is always available, but the system becomes vulnerable to noise and measurement loss
Solution Approach 1:
The patent introduces history data as an intermediary between direct sensor measurements and SOH estimation. Instead of relying solely on potentially noisy sensor readings, the system uses accumulated history data to derive SOH estimates, which are then refined by actual measurements. This intermediary approach filters out noise and maintains reliability even when sensor measurements are lost or corrupted
Data Source
AI summary
A state estimation method for an energy storage device includes: acquiring, by a first method, a first probability distribution that expresses the state of the energy storage device 61 in the form of a probability distribution; acquiring, by a second method, a second probability distribution that expresses the state of the energy storage device in the form of a probability distribution; and estimating the state of the energy storage device on the basis of the first probability distribution and the second probability distribution.