[PDF] Development of Battery Management System

However, as described in the previous section, since the lithium-ion batteries have been adopted in more fields, if we develop products customized for each field

[PDF] Battery Management Systems for Lithium-Ion Batteries - ResearchGate

Build an open system that allows the implementation of different charging and balancing algorithms, and that is able to be used with different battery models; 3

[PDF] Battery Management Systems - University of Twente Research

Battery Management Systems-Design by Modelling making the BMS more intelligent building blocks inside the battery pack are often referred to as cells

Design and Implementation of Battery Management System for

For this project, 18650 Lithium-Ion battery is used to develop battery management for 144V 50Ah As lithium-ion batteries have high value of specific energy, high

[PDF] Battery Management System (BMS) Design for Lithium-ion Batteries

Nothing in this presentation shall be construed or interpreted as official contractual direction or any requirement to make constructive change to deliverables or

[PDF] Battery-Management-System Requirements - Dr Gregory L Plett

Informs the application controller how to make the best use of the pack right now ( e g , power limits), control charger, etc □ There is a cost associated with battery

FUJITSU TEN TECH. J. NO.42(2016)

Yoshikazu FUJITA

Yasuyuki HIROSE

Yusuke KATO

Takahiro WATANABE

Development of Battery Management System

Due to their high e?ciency and high energy density, lithium-ion batte ries have been adopted for mobile

electronic devices and electric vehicles. ?ey have been increasingly used further for various applications,

such as small mobility vehicles (electric motorcycles, golf carts, etc. ), stationary batteries for HEMS (Home Energy Management System), trucks/buses and industrial machinery. Howev er, they have risks of ?re hazard and electric shock if being used incorrectly. In order to use the highly e?cient lithium-ion batteries safely and e?ectively, a battery management system (BMS) is needed.

Among the BMS, technologies of the

battery capacity estimation and the malfunction detection are important. FUJITSU TEN has developed a universal BMS PF (platform) that can be us ed for a variety of applica tions. ?is paper elaborates the development concept, the safety desig n technology and the highly-accurate battery capacity estimation technology of the universal BMS PF.

FUJITSU TEN TECHNICAL JOURNAL

FUJITSU TEN TECH. J. NO.42(2016)

2.1 Change in Development Process

Fig. 1 Block Diagram of Electric Vehicle

Introduction

Development Concept

Fig. 1

Fig. 2

Development of Battery Management System

FUJITSU TEN TECH. J. NO.42(2016)

2.2 Development Specifications of Universal

BMS PF

Fig. 2 Conventional Development Process

Fig. 4 Requirements per Purpose and Specifications of Universal BMS PF Fig. 3 Advanced Development Process for Widely-used PF

Fig. 3

Fig. 4

Fig. 5

Fig. 6

Fig. 7

Fig. 5

Fig. 7

FUJITSU TEN TECHNICAL JOURNAL

FUJITSU TEN TECH. J. NO.42(2016)

2.3 Method of Materializing Universal BMS PF

Fig. 5 Block Diagram of 96-cell Full Function Universal BMSFig. 6 Block Diagram of 48-cell Universal BMS for

Stationary Battery for HEMS

Fig. 7 Block Diagram of 20-cell Universal BMS

for Small Mobility Vehicle

Fig. 5

Fig. 6

Fig. 7

Fig. 5

Fig. 6

Fig. 7

Fig. 5

Fig. 7

Development of Battery Management System

FUJITSU TEN TECH. J. NO.42(2016)

2.4 Satisfaction of Required Functions

(Cell Balancing)

Fig. 8 Cell Balancing

Fig. 5

Fig. 6

Fig. 7

Fig. 5

Fig. 7

Fig. 8

Fig. 9

Fig. 11

Fig. 12

FUJITSU TEN TECHNICAL JOURNAL

FUJITSU TEN TECH. J. NO.42(2016)

3.1 Importance of BMS Safety Design and Compliance

with Standard of Functional Safety Fig. 9 Conventional StructureFig. 10 Method of Achieving Cell Balancing during Operation

Safety Design Technology

Fig. 5

Fig. 6

Fig. 7

Fig. 5

Fig. 7

Fig. 10

Fig. 11

Fig. 12

Development of Battery Management System

FUJITSU TEN TECH. J. NO.42(2016)

3.2 Safety Design against Fire Hazard from Cell

(Compliance with ASIL D, Functional Safety)

3.2.1 Design Concept3.2.2 Design of First Safety Mechanism

Fig. 11 Fire Hazard from Lithium-ion Battery

Fig. 13 Safety Design Concept to Prevent Fire

Hazard from Battery

Fig. 14 1st SM Structure on Universal BMS PF

Fig. 12 High Voltage Electric Shock

Fig. 11

Fig. 12

Fig. 13

Fig. 14 (1) Measurements against malfunction common to cell monitoring ICs

Fig. 1

5 (1) Diagnosis of cell monitoring IC (2nd SM) (2) Diagnosis of microcomputer and power supply

IC (2nd SM)

(3) Diagnosis of relay control circuit and relay (2nd SM) (1) Insulation resistance detection circuit

Fig. 17

FUJITSU TEN TECHNICAL JOURNAL

FUJITSU TEN TECH. J. NO.42(2016)

3.2.3 Design of Second Safety Mechanism

Fig. 15 Internal Structure of Cell Monitoring ICFig. 16 Turning-off of the Relay by Power Supply

IC in Case of Microcomputer's Malfunction

Fig. 11

Fig. 12

(1) Measurements against malfunction common to cell monitoring ICs

Fig. 1

5 (2) Measurement against malfunction common to microcomputers

Fig. 16

(1) Diagnosis of cell monitoring IC (2nd SM) (2) Diagnosis of microcomputer and power supply

IC (2nd SM)

(3) Diagnosis of relay control circuit and relay (2nd SM) (1) Insulation resistance detection circuit

Fig. 17

Development of Battery Management System

FUJITSU TEN TECH. J. NO.42(2016)

3.3 Safety Design against Electric Shock

4.1

Necessity for Accurate Estimation of

Battery Status

Fig. 17 Insulation Resistance Detection CircuitFig. 18 Circuit for Voltage Measurement at Charging Inlet

Development of Battery Status

Estimation Algorithm

(1) Diagnosis of cell monitoring IC (2nd SM) (2) Diagnosis of microcomputer and power supply

IC (2nd SM)

(3) Diagnosis of relay control circuit and relay (2nd SM) (1) Insulation resistance detection circuit

Fig. 17

(2) Voltage measuring circuit at charging inlet

Fig. 18

Fig. 19 Fig. 20

FUJITSU TEN TECHNICAL JOURNAL

FUJITSU TEN TECH. J. NO.42(2016)

4.2 Battery Status Estimation Algorithm

4.2.1 Battery Equivalent Circuit Model

Fig. 19 Image of Battery CapacityFig. 20 Battery Equivalent Circuit Model (1) Diagnosis of cell monitoring IC (2nd SM) (2) Diagnosis of microcomputer and power supply

IC (2nd SM)

(3) Diagnosis of relay control circuit and relay (2nd SM) (1) Insulation resistance detection circuit

Fig. 17

Fig. 20

Development of Battery Management System

FUJITSU TEN TECH. J. NO.42(2016)

4.3 Estimation Accuracy Evaluation

4.2.2 Structure of Battery Capacity Estimation

Algorithm

Fig. 21 Configuration of Battery Capacity

Estimation Algorithm

Fig. 20

Fig. 21

(1) Calculation of internal resistance (2) Calculation of charge amount by charging and discharging (3) Estimation of internal temperature of battery (5) Reduced capacity estimation

Fig. 22

Fig. 23

FUJITSU TEN TECHNICAL JOURNAL

FUJITSU TEN TECH. J. NO.42(2016)

Fig. 22 Transition of SOC Estimated Value and True Value Fig. 23 Transition of Estimated Value and True Value of Reduced Capacity (Degradation to Capacity)

Conclusion

Fig. 20

Fig. 21

(1) Calculation of internal resistance (2) Calculation of charge amount by charging and discharging (3) Estimation of internal temperature of battery (5) Reduced capacity estimation

[PDF] [PDF] Development of Battery Management System - DENSO TEN