Battery Pack SOH Detection via Dynamic Power Control
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Solution Overview
Problem
Existing SOH detection methods in energy storage systems suffer from low precision due to changes in the OCV-SOC relation curve with battery aging, leading to inaccurate SOC and SOH values, and pose overcurrent risks during charging and discharging.
Innovation Solution
A method where a main controller adjusts the output power of a power generation module based on allowable charge or discharge power to ensure the battery pack completes a full charging or discharging process, eliminating polarization phenomena and enabling precise SOH calculation by static standing after charging or discharging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the battery pack undergoes full charging or discharging to detect SOH, then the detection precision is improved, but the system power requirement increases and may cause overcurrent risks
Solution Approach 1:
The system dynamically adjusts the power generation module's output power based on real-time battery status and system requirements. During SOH detection, the controller modulates the power generation to provide necessary charge/discharge currents while preventing overcurrent conditions, enabling safe full charging/discharging cycles for accurate SOH measurement
Solution Approach 2:
The controller changes the operating parameters of the power generation module during SOH detection, adjusting output power levels according to battery state. By modifying power generation parameters dynamically, the system enables complete charging/discharging cycles required for accurate SOH detection while maintaining safe current levels
2Measurement precision
If the output power of power generation module is adjusted to enable full charging or discharging, then the available capacity measurement accuracy is improved, but the control complexity increases
Solution Approach 1:
The power generation module serves multiple functions: normal power generation, battery charging, discharging, and SOH detection. By making the power generation system multi-functional, the controller can adjust output power for different operations including complete charging/discharging cycles needed for accurate available capacity measurement, without requiring separate dedicated equipment
Solution Approach 2:
The controller implements feedback control by continuously monitoring battery state and adjusting power generation output accordingly. During SOH detection, the controller receives battery status information and modulates power generation to achieve complete charging/discharging cycles, enabling accurate available capacity measurement through closed-loop control
3Measurement precision
If the battery pack is left to stand statically after charging or discharging to eliminate polarization, then the SOH calculation precision is improved, but the detection time increases
Solution Approach 1:
The controller performs preliminary actions by completing full charging or discharging cycles before SOH detection. By ensuring the battery reaches complete charge or discharge states in advance, the subsequent static standing period allows polarization elimination and accurate SOH calculation without requiring extended total detection time
Data Source
AI summary
This application discloses a state of health (SOH) detection method and apparatus, and an energy storage system. A main controller in the method can adjust an output power of a power generation module based on an allowable charge or discharge power of a battery pack, so as to cause the output power of the power generation module to charge or discharge the battery pack while satisfying a required system power. This enables the battery pack to complete a full charging or discharging process, so as to obtain a currently available capacity of the battery pack accurately and implement precise calculation of the SOH.