NC#STATE#UNIVERSITY!
Battery#Management#System#
Software#Report#<#LabVIEW#GUI#
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Aneeshwar!Raghu!Danda!
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Bharat!Balagopal!
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Battery!Management!System!.!Final!Report!
1.!Introduction!
This! projects! deals! with! developing! a! universal! battery! management! system! that! is! capable! of!
controlling! the! rate! of! charge! and! discharge! of! the! battery.! The! system! also! functions! as! a! data!
acquisition!unit!,!that!can!read!battery!voltage!and!current.!The!two!major!components!of!the!system!
are!hardware!and!software.!This!report!focuses!on!the!software!aspect!of!the!project.!The!software!uses!
LabVIEW!as!a!platform!to!interface!with!the!hardware!for!both!acquisition!and!control.!
1.1!BMS!–!Software!
The! LabVIEW! GUI! is! primarily! divided! into! two! portions.! the! control! panel! and! the! display! panel.! ! The!
control!panel!allows!the!user!to!perform!experiments!such!as!charging!and!discharging!the!battery!and!
log!the!corresponding!data.!The!display!panel!presents!the!experimental!data!on!a!waveform.!
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Figure!1.!BMS!GUI!
Battery!Management!System!.!Final!Report!
2.!Control!Panel:!
2.1!Battery!Chemistry:!
!!The!user!can!select!the!type!of!battery!being!tested!using!the!radio!buttons!as!shown!in!fig!().!When!a!
particular! battery! chemistry! is! selected,! the! user! is! notified! the! Nominal,! Maximum! and! Minimum!
voltage!per!cell!and!the!corresponding!battery!image!is!shown!for!visual!appeal.!!
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Figure!2.!Lead!Acid!Battery!
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Figure!3.!NiMH!Battery!
2.2!Battery!Information:!
This!indicator!provides!the!user!with!the!nominal,!maximum!and!minimum!voltage!per!cell!for!the!
battery!chemistry!selected.!
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Figure!4.!Voltage!Ratings/Cell!
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2.3!Logging!Interval:!
Battery!Management!System!.!Final!Report!
The!user!can!control!the!frequency!of!the!data!being!logged!,!by!defining!the!“Logging!Interval”!time!in!
milliseconds.!!
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Figure!5.!Logging!Interval!
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2.4!Algorithms!<not!yet!implemented>:!
Provisions!have!been!made!to!simulate!and!compare!the!various!SOC!estimation!algorithms.!
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Figure!6.!Options!to!Simulate!or!Compare!Algorithms!
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2.5!Mode!of!operation:!
Battery!Management!System!.!Final!Report!
There!are!four!different!modes!of!operation:!!Constant!Current!Constant!Voltage!(CCCV),!Charge,!
Discharge!and!Custom.!At!present!the!Charge,!Discharge!and!Custom!modes!have!been!implemented.!
The!charge!and!discharge!modes!further!have!two!options!–!Continuous!and!Pulsed!mode.!The!
“Continuous”!mode!charges/discharges!the!battery!at!the!specified!rate!for!the!time!set!by!the!user.!The!
“Pulsed”!mode!charges/discharges!the!battery!at!regular!intervals!whose!frequency!and!number!of!
cycles!is!determined!by!the!user.!
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Figure!7.!Different!Modes!of!Operation!Available!
2.6!Charge!mode:!
The!charge!mode!controls!the!duration!and!rate!of!charge!of!the!battery!with!respect!to!the!battery!
capacity!(C).!At!present!the!value!of!C!is!set!to!1Ah.!For!the!“Continuous”!mode!the!user!can!enter!the!
total!charge!time!of!the!battery,!whereas!the!“Pulsed”!mode,!the!user!can!enter!the!duration!of!each!
pulse!and!also!the!number!of!charge!cycles!that!need!to!be!run.!
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Figure!8.!Charging!Mode!Panel!
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2.7!Discharge!mode:!
Battery!Management!System!.!Final!Report!
The!discharge!mode!controls!the!duration!and!rate!of!discharge!of!the!battery!with!respect!to!the!
battery!capacity!(C).!At!present!the!value!of!C!is!set!to!1Ah.!For!the!“Continuous”!mode!the!user!can!
enter!the!total!discharge!time!of!the!battery,!whereas!the!“Pulsed”!mode,!the!user!can!enter!the!
duration!of!each!pulse!and!also!the!number!of!discharge!cycles!that!need!to!be!run.!
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Figure!9.!Discharging!Mode!Panel!
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2.8!Custom!mode:!
In!the!custom!mode!the!user!customize!his!experiment!by!choosing!to!run!a!series!of!charge,!discharge!
or!rest!cycles.!The!user!can!also!define!the!rate!and!duration!of!each!cycle.!!A!total!of!up!to!9!different!
cycles!can!be!run!in!an!experiment.!
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Figure!10.!Custom!Mode!Panel!
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2.9!Summary:!
Battery!Management!System!.!Final!Report!
This!field!displays!the!summary!of!the!current!experiment!that!is!being!performed,!which!comprises!of!
the!battery!chemistry,!mode!of!operation,!duration,!rate!and!time!started!and!completed.!!
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Figure!11.!Summary!Field!
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2.10!Start/Stop:!
There!are!two!buttons!present!that!determine!the!start!and!stop!of!the!experiment.!
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Figure!12.!Start!&!Stop!Buttons!
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3.!Display!Panel:!
Battery!Management!System!.!Final!Report!
3.1!Waveforms:!
This!displays!the!instantaneous!value!of!the!voltage!and!current!being!read!from!the!battery.!The!NI!
6009!DAQ!reads!the!values!and!pass!it!on!to!the!GUI!for!display.!Provisions!have!been!made!for!
displaying!the!temperature!waveform!of!the!battery.!
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Figure!13.!Display!Panel!for!Waveforms!
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3.2!Data!Saved!to!file:!
Battery!Management!System!.!Final!Report!
Displays!the!complete!path!and!file!name!where!the!experiment!data!is!logged.!The!file!is!located!in!a!
folder!called!“BMS!Data”,!which!is!located!in!the!same!directory!as!the!BMS!GUI.!The!file!also!takes!the!
name!BMSData<x>,!where!x!is!an!integer!that!takes!the!next!available!value.!
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Figure!14.!Location!of!Logged!Data!File!
3.3!Logged!Data:!
This!table!displays!the!voltage!and!current!read!from!the!battery!in!real!time.!
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Figure!15.!Real!Time!Logged!Data!
3.4!SOC:!
Once!the!different!SOC!estimation!algorithms!are!implemented,!the!SOC!can!be!displayed!on!the!meter.!
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Figure!16.!SOC!Estimation!Algorithm!Result!Display!
4.!Future!Work!
Battery!Management!System!.!Final!Report!
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Including!the!capacity!of!the!battery!and!monitoring!the!cut!off!voltages.!
Including!the!SOC!estimation!Algorithms.!
Implementing!CCCV.!
Implementing!Pulsed!mode.!
Including!the!temperature!effects.!