Liebert NXa UPS Battery Management

8/2/2019 Liebert NXa UPS Battery Management

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Battery Management

ENPC Engineering Team

Sep. 2003


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Contents

1.Overview

2.Basic Settings

3.Charging

4.Discharging

5.Maintenance6.Battery Curve


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1.Overview

1.1 Typical Charge & Discharge ProcessVoltage Current

Identify: Equalize Charge (Current Limiting or Constant Voltage ), Floating charge,Dishcharge process

40Ah


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(1) Charging Management

(2) Discharging Management

(3) Maintenance

(4)Battery Curve Customization

1.2 Scope


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2.Basic Settings

(1) Single Group Battery Capacity : 7-2500Ah(26Ah) C

(2) Number of Battery Groups: 1-10 (1)

(3) Battery cells number: 200-360 (240)(4) Battery Type Configuration: 1-20 (1)

1:VRLA 2:High discharge rate VRLA

(5) Battery Life Configuration: 12-120month (70month)

(6) Battery Curve(Characteristic): load from text file


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3.Charging

Typical process: current-limit equalize charge --->const-voltage equalize

charge --->float charge (Q: charging rate increase)

(1) Equalize charge/float charge auto transfer:

based on charging current, thresholds settable.

(2) Equalize charge maximum current limiting:settable, auto implemented by charger

(3) Equalize charge time protection:

settable, continuous equalize charging time limit.(4) Float charge voltage temperature compensation:

settable, negative coefficient

3.1 Functions


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3.2 Related Settings (1)

(1) Equalize Charge Allowed: 1/2 (1)

1:Enable 2:Disable

(2) Battery Float Charge Voltage: 2.20V~2.30V (2.25)

(3) Battery Equalize Charge Voltage: 2.30V~2.40V (2.35)

(4) Battery Charge Current Limit: 0.02~0.25C (0.2C)

for High discharge rate VRLA 0.02~0.10C (0.1C)

(5) Threshold for Equalize charge to Float charge: 0.005~0.025C(0.01C)

(6) Threshold for Float charge to Equalize charge: 0.03~0.07C(0.05C)

Note: Actual Current = above set pointSingle Group Battery CapacityNumber of Battery Groups


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(7) Temperature Compensation Allowed: 1/2 (1)

(8) Temperature Compensation Central Point: 2030 (25)

(9) Temperature Compensation Factor: 0.003~0.005

(Vf is limited to [ 2.2, 2.3])

(10) Equalize Charge Protect Time Limit: 960~1800 min(1440)

3.2 Related Settings(2)


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4.Discharging

Typical process: discharging --->pre-warning --->EOD shutdown

(Q: charging rate decrease)

(1) Backup time forecast:

based on Q, Tpb and Kc. (Tpb--basic backup time at P, Kc---Capacity Factor)

(2) Under-voltage pre-warning:

interpolation using 3-min and 6-min (P, U) curve, also refined by user desiredEOD

(3) End of discharging (EOD) protection:

lowest protection point settable, real shutdown point is regulated according topre-warning voltage.

(4) Small current discharge protection:

settable, continuous discharging time limit.

4.1 Functions


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4.2 Related Settings

(1) Battery Low Warning Time 3~60 min (5)

(2) EOD (End of discharge) Voltage 1.20~1.90V (1.70)

(3) Small Current Discharge Protection 1200~1800min(1440)


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5.Maintenance

5.1 Maintenance Test

Usage:

Periodic reactivation, discharging 20% rated capacity with set power.Conditions:

Battery fully charged, load 20~80%.

Trigger:

Manually through LCD panel or Automatically.

Battery Self Test Interval 720~4320 hour (1440)

Maintenace Test Power in battery curve data (total KW)


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5.2 Capacity Test (1)

Usage:

Battery curve update, discharging to EOD with whole load.

Conditions:

Battery fully charged, load 20~80%.

Trigger:

Manually through LCD panel .


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5.2 Capacity Test (2)

L ie b e rt N X a 2 0 0 3 -0 1 -2 2 1 2 : 3 0 : 3 66 0k V A -3 X 3 U n it #1 N o rm a l

?

B y p a s sM a i n

V p h a s e V

Ip h a s e A

F re q . H z

V lin e VP . F .

A (A B )

2 2 02 0 .5

50.1

3 8 00 .9 9

B (B C )

2 2 0

2 0 .5

50 .1

3 8 00 .9 9

C (C A )

2 2 0

20.5

50 .1

3 8 00.99

F 2 F 4 F 5F 1 F 3

O u t p u t

In p u t B r e a k e r C lo s e d 0 1 -1 2 1 2 :2 8 :1 6

M a n u a l T u rn O n 0 1 -1 2 1 2:3 0 :0 6

U P S in N o rm a l M o d e 0 1-2 2 1 2 :3 0:1 6

B a t t e r y w i l l b e d e p l e t e d ,C o n f i r m o r c a n c e l

E S C


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5.3 Battery Life Forecast


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6.1 Battery Curve Content

6.Battery Curve

(1) Backup time curve: (P,Tpb)

(2) Prewarning curves: (P,U) 3min and 6min

(3) Some set points

(4) Some coefficients


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6.2 Pre-warning Curves Example

Battery Low Voltage

1.651.71.751.81.851.91.95

0.

83

1.

11

1.

5

1.

77

2.

46

3.

33

3.

74

4.

38

5.

36

W/AH

Voltage

UP3

UP6


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6.4 Battery Curve Data Description(2)

(1) [battery_curve_base_num]: data number in the file

(2) [battery_curve_base_data]: curve data

Line 1: discharging power for each cell (W/cell)Line 2: corresponding backup time

Line 3: corresponding dischargable capacity percentage (1 for 10hour discharging)

Line 4: discharging power/capacity (W/Ah)

Line 5: corresponding 3-min prewarning voltage

Line 6: corresponding 6-min prewarning voltage

Line 7-9: other set points or


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6.5 Load Battery Curve from file


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6.6 Customize Battery Curve (1)

For VRLA battery, custom battery curve could be built according to batterydatasheet or experimental data.

Custom battery curve can enhance the accuracy of backup time forecast, andprovide better battery and load protection .

Generally, only the first 3 lines (backup time curve) should be customized.


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CSB 26Ah Dtasheet and Curve


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CSB 40Ah Dtasheet and Curve


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To build custom battery curve without datasheet, you can specify thedischarging power in the first line by replacing the C in the followingtemplate with real battery capacity .


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6.7 Battery Parameters


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Thanks

Documents

Liebert NXa UPS Battery Management