Battery Derating Control Using Load Buffers and Safety Margins
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rechargeable energy storage systems face challenges in controlling power outtake during transient conditions to avoid impacting the State of Health (SoH) of the system, particularly in applications like electric vehicles and marine vessels.
Innovation Solution
A method for determining a derating factor for rechargeable energy storage systems, which involves detecting electrical loads and using buffer zones to dynamically adjust the derating factor based on accumulated load values and safety margins, thereby minimizing SoH degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the electrical load is limited to extend battery life, then the State of Health of the rechargeable energy storage system is improved, but the productivity and power availability of the system deteriorates
Solution Approach 1:
The patent implements dynamic load management by continuously monitoring the electrical load and adjusting the derating factor in real-time based on accumulated load values and safety margins, rather than applying static load limitations. This allows the system to maximize power availability while protecting the battery through adaptive control
Solution Approach 2:
The patent changes the parameter of load derating from a fixed value to a dynamically calculated derating factor based on multiple parameters including accumulated load values, safety margins, and threshold comparisons. This enables flexible adjustment of power output to balance battery protection with productivity requirements
2Reliability
If buffer zones are reserved for transient conditions, then the reliability of the rechargeable energy storage system is improved, but the productivity and efficient use of power capacity deteriorates
Solution Approach 1:
The patent applies partial derating by calculating a derating factor that is adjusted based on the degree to which accumulated load values exceed thresholds. Rather than always applying full derating, the system applies partial derating when safety margins are sufficient, thereby efficiently using power capacity while maintaining reliability
Solution Approach 2:
The patent implements feedback control by continuously monitoring the electrical load, calculating accumulated load values, comparing them against thresholds, and adjusting the derating factor based on safety margin evaluations. This closed-loop control optimizes buffer zone utilization while maintaining system reliability
3Reliability
If the derating factor is increased to protect the battery, then the State of Health is improved, but the electrical load capability and productivity of the system deteriorates
Solution Approach 1:
The patent dynamically adjusts the derating factor based on real-time monitoring of accumulated load values and safety margin evaluations, rather than using a fixed high derating factor. This allows the system to maintain high power capability when battery conditions permit while protecting State of Health when necessary
Data Source
AI summary
A method for determining a derating factor for a rechargeable energy storage system. The derating factor is indicative of the rate at which an electrical load, imparted on said rechargeable energy storage system, is reduced, said rechargeable energy storage system being associated with at least a first load threshold and at least a second load threshold being located further away from a zero electrical load value than the first load threshold. The method includes determining a safety margin value by combining an accumulated first load value and an accumulated second load value and relating the thus combined values with said operating time range, and comparing said safety margin value to at least one safety margin threshold value in order to determine whether or not said derating factor should be modified.