Slave BMS ID Allocation Using Rack-Level RSSI Association

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Solution Overview

Problem

In energy storage systems (ESS) with multiple battery racks, existing BMS systems face challenges in automatically identifying and allocating IDs to slave BMSs within the same battery rack, leading to potential installation errors and increased installation time.

Innovation Solution

A master BMS system that wirelessly transmits cell balancing and temperature measurement signals, uses RSSI levels to determine the association of slave BMSs within the same rack, and allocates IDs based on signal strength, ensuring accurate ID allocation and communication channel adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If wireless communication is used for BMS signal transmission, then installation flexibility and remote monitoring capability are improved, but signal interference and ID allocation errors between multiple battery racks occur

Engineering Contradiction:
Improveinstallation flexibilityVSAvoidsignal transmission accuracy
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The system segments the wireless communication space by using physical rack structures as boundaries. Each battery rack is treated as an independent communication zone, with the master BMS in each rack managing only slave BMSs within its own rack. This segmentation prevents signal interference between different racks while maintaining wireless communication flexibility within each rack.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system implements a feedback mechanism where slave BMSs transmit their received signal strength indication (RSSI) values back to the master BMS. The master BMS uses this feedback to identify which slave BMSs are located in the same rack by selecting those with the strongest signal strengths. This feedback loop enables automatic rack-specific ID allocation without manual intervention, resolving the reliability issue while preserving wireless adaptability.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If manual ID input is required for slave BMS, then ID allocation accuracy is improved, but installation time and operational complexity increase

Engineering Contradiction:
ImproveID allocation accuracyVSAvoidinstallation time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system enables self-service automatic ID allocation where the master BMS automatically identifies slave BMSs in the same rack based on RSSI feedback and allocates IDs without requiring manual input from installers. The slave BMSs automatically provide their signal strength information, and the master BMS automatically processes this information to determine rack membership and assign appropriate IDs. This eliminates manual intervention entirely, reducing installation time while maintaining accuracy through the RSSI-based identification mechanism.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system changes the parameter used for ID allocation from manual input values to automatic RSSI signal strength measurements. By using the physical parameter of signal strength as the basis for determining rack membership and allocating IDs, the system transforms a manual process into an automatic one. The master BMS compares RSSI values and automatically assigns IDs based on the strongest signals, ensuring accuracy while dramatically reducing installation time and operational complexity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3955365B1System for automatically assigning id to slave bms
Publication Date: 2023.12.13 LG ENERGY SOLUTION LTD
  • EP3955365B1 patent drawingFigure 1
  • EP3955365B1 patent drawingFigure 2
  • EP3955365B1 patent drawingFigure 3

AI summary

Disclosed is a master battery management system (BMS) including: a transmission unit for transmitting a cell balancing start command signal and a temperature measurement command signal to a plurality of slave BMSs; a wired communication unit for transmitting a FAN ON signal to a plurality of fans after the transmission unit wirelessly transmits the cell balancing start command signal; a reception unit for receiving an association signal from an associated slave BMS having a difference in temperature of a printed circuit board (PCB) board of a corresponding slave BMS and a temperature of a PCB substrate of a corresponding slave BMS that is greater than a preset value; and a control unit for determining that the associated slave BMS is disposed in the same rack, and changing an ID and communication channel of the associated slave BMS to a specific value.