state-of-the-art of hardware-in-the-loop solutions for battery management system testing

Jorge Varela Barreras, David A. HoweyDepartment of Engineering ScienceUniversity of Oxford

[email protected]

[email protected]

users.ox.ac.uk/~engs1053/

State-of-the-art of Hardware-in the-loop Solutions for BatteryManagement System Testing

HVM CATAPULT: Energy Storage ConferenceInternational Digital Laboratory

24th Sep. 2015

LIFETIMELIMITED

COSTLIMITED

R&DKEY

TAKEAWAY

HIGHEREFFICENCY AND

LIFETIME

Facts about LIB

19911st cell

by Sony

2nd

MARKETafter lead

acid

2013+15 bi US$REVENUE*

HIGHERSPECIFIC ENERGY

AND POWER

NOMEMORYEFFECT

SOALIMITED


*Source: Foster & Sullivan


24th Sep. 2015

LIFETIMELIMITED

COSTLIMITED

R&DKEY

TAKEAWAY

HIGHEREFFICENCY AND

LIFETIME

Facts about LIB

19911st cell

by Sony

2nd

MARKETafter lead

acid


HIGHERSPECIFIC ENERGY

AND POWER

NOMEMORYEFFECT

SOALIMITED


*Source: Foster & Sullivan

BMSREQUIRED

DIS/CHARGEMANAGEMENT

DIAGNOSISDIAGNOSISSOC, power

capability SOH,SOF…

PROTECTIONAGAINST HAZARDS

MONITORING

MANAGEMENTDATA

MANAGEMENT


24th Sep. 2015

MonitoringProtection againstProtection against

hazardsCharge/discharge management Diagnosis

Datamanagement

High-level representation of BESS

BMSREQUIRED

A BMS can be defined as a group of related HW and SW units, dedicated to deal with or

to control the performance of a battery according to certain set of principles or procedures

High-levelrepresentation of a

BESS


24th Sep. 2015

Advanced BMS functional tree

MonitoringProtection againstProtection against

hazardsCharge/discharge management Diagnosis

Datamanagement

Manage the batteryBMS

REQUIRED

C. Fleischer, J. V. Barreras et al., “Development of software and strategies for Battery Management System testing onHIL simulator,” Proceedings of the 2016 Eleventh International Conference on Ecological Vehicles and RenewableEnergies (EVER). Monte-Carlo: IEEE Press, 2016.


24th Sep. 2015

BMS HW & SW development

V-model

INTEGRATION

TESTSREQUIRED

DURINGINTEGRATION

BMSPRODUCT

MANAGEMENTREQUIRED



24th Sep. 2015

Challenges of BMS testing

Source: Shanghai Keliang Information Tech. & Eng. Co., Ltd.


24th Sep. 2015

BMS testing: real vs virtual battery

BMSREQUIRED

PROBLEMREAL LIB

Cost and time effectiveness, feasibility, reproducibility and risksbeyond the normal range of operation, at early stages in the

BMS development process or during fault simulation

Need to test BMS controller HW and SW at system level

BMS testing in advanced HIL simulator


24th Sep. 2015

c. 2010COMMERCIALSOLUTIONS

COMPLEXSYSTEMS

HIGHMODULARITY

Custom made SW solutions:

Simulink, MappleSim, C++, LabView…

RT-Lab, ControlDesk, ConfigurationDesk…

+ Controllable DC voltage source

(for BMS powering or pack voltage simulation)

FIU on/off-board

State-of-the-art of HIL simulator


24th Sep. 2015

FIUon/off-board




24th Sep. 2015

Other


Common mode isolation in order of +1 kV DC CH-TO-CH, CH-TO-GND

Temperature and current sensor emulation, typ. range +/- 10V and

accuracy around ± .1 / 1 %

Cell voltageemulator

No. of channels from a few up to +200

Accuracy in order of mV: +/- 0.5 / 1 / 3 mV

Max. update rate for all cells up to 1 kHz, i.e. not sufficient for certain test

High voltage resolution, in order of .1 mV

Range from around 0 to + 5 / 6 / 8…V

Balancingcurrent

Balancing current range +/- 0.5 / 1 / 2.5 / 3 A and w/ parallelization up to 10 A

Balancing current accuracy in order of mA: +/- 1 / 2 / 4 mA

High balancing current resolution, in order of .1 mA

GENERAL SPECS


24th Sep. 2015

Application case – dSPACE HILS

J. V. Barreras et al., “An Advanced Hardware-in-the-loop Simulation Battery Model for Battery Management Systemtesting,” IEEE Transactions on Industry Applications, 2016, to be published.

sBMS v6Lithium Balance

Commercial

BMSSystem level

tests


24th Sep. 2015

Custom battery system model



24th Sep. 2015



Fuse and switch box model


24th Sep. 2015


LIB pack electro-thermal model coupled with aging model

40 AhKokam

NMC-cathode

Modelling approach

Equivalent Circuit Model approachSOC, temperature and ageing dependencies

Impedance-based model + thermal model + aging model

Characterization techniques

Pulse power characterizationOCV test and Capacity check

Electrochemical impedance spectroscopy (EIS)Anisotropic thermal diffusivity test

Life degradation

Accelerated cycling with a real driving cycle andconducting RPT every 100 cycles


24th Sep. 2015



24th Sep. 2015


LIB electro-thermal cell model validation in simulation



24th Sep. 2015

BMS testing in HIL simulator

(a) 32 cells voltages vs BMS measured max. and min. (b) Detailed view

Dynamic discharge



24th Sep. 2015



(a) 32S pack current and pack voltage in time

(b) Switch box contactor logic

(c) Experimental vs BMS measured cells temperatures

Overtemperature during dynamic discharge


24th Sep. 2015


(a) Cells voltages in time (b) Cells temperatures in time

External short circuit close to cell’s tabs



24th Sep. 2015


(a) 32S pack current and pack voltage in time(b) Cells voltages and balancing currents

Charge process



24th Sep. 2015


(b) Experimental vs BMS measured cellstemperatures in time

(a) 32S pack current and pack voltage in time

Charge process at low temperatures



24th Sep. 2015


Critical zero volt mode.Higher series resistance for a single cell.

Model based fault insertion



24th Sep. 2015

Malfunction of chargerNoise in cell voltage measurement

(a) Pack current and pack voltage in time

(b) 32 cells voltages in time


Model based fault insertion



24th Sep. 2015

Application case 2 – dSPACE HILS

Single particle model implemented on a dSPACE real-time target. See users.ox.ac.uk/~engs1053

Identified to major challenges related to real-time targetODE solvers:

• only fixed time-step

• no iterative methods allowed

ensure the solution within the sample time


24th Sep. 2015

Conclusions

More demanding battery applications, e.g. xEVs, requiremore advanced BMSs. In turn, more advanced BMSs

demand more complex and customized testing at all stagesof development

Tests on a HIL simulator can offer in comparison with teston real batteries key advantages in terms of cost, testing

times, flexibility, traceability, ease to reproduce or safety, inparticular beyond the normal range of operation, at earlystages of development or under fault insertion scenarios


24th Sep. 2015

Acknowledgements

UK's innovation agency for supporting the project AMPLiFII(Automated Module-to-pack Pilot Line for Industrial Innovation)

Jorge V. Barreras, David A. HoweyDepartment of Engineering ScienceUniversity of Oxford

[email protected]

[email protected]

users.ox.ac.uk/~engs1053/

State-of-the-art of Hardware-in the-loop Solutions for BatteryManagement System Testing