Use of large storage batteries to manage demand at a mine

1. USE OF LARGE STORAGE BATTERIES TO
MANAGE DEMAND AT A MINE
Mark Mills

2. The work presented has been used with the permission of Glencore
CSA mine.
ACKNOWLEDGEMENTS
BATTERY POWER COMPENSATION ON 11kV NETWORK
The project has not been implemented on site and at this point is a
theoretical assessment.

3.  Supply Authority 132kV network power constrained.
 Reliance on diesel generators to fill energy shortfall.
 Expensive cost of diesel compared to electricity.
 Optimise the power available from the grid.
 Return on investment.
ASSESSMENT CRITERIA
BATTERY POWER COMPENSATION ON 11kV NETWORK

4. SUPPLY CONCEPTS
BATTERY POWER COMPENSATION ON 11kV NETWORK
 Site must operate within the approved transfer capacity from grid.
 Reliable energy source, no requirement for fuel source.
 Remove peak overhead allowance from grid connection.
 Least capital intensive than other systems such as solar system and less
dependant on external factors such as weather.
 Winder Loads: Very high cycle times with minimal rest periods, maximum
utilisation.

5.  Koepe Winder has two skips that
partially balance load.
 Drum winder starts from dead load at
bottom of shaft.
WINDER LOADS
BATTERY POWER COMPENSATION ON 11kV NETWORK

6. ‐5000
‐4000
‐3000
‐2000
‐1000
0
1000
2000
3000
4000
5000
0 50 100 150 200 250 300
Time (s)
Motor Shaft Power vs Time
kW
Batteries will remove peaks from the power load profiles.
Batteries will recharge during this period
of the load profile
Winder VSD Regeneration
DRUM WINDER LOAD PROFILE
BATTERY POWER COMPENSATION ON 11kV NETWORK

7. KOEPE WINDER LOAD PROFILE
BATTERY POWER COMPENSATION ON 11kV NETWORK
Batteries will recharge during these periods of the load profile
No VSD Regeneration
Batteries to remove peaks from the power load profiles.
kW
Time (s)

8. 11kV NETWORK
BATTERY POWER COMPENSATION ON 11kV NETWORK
Fibre Optic Link
VSD Power

9. WINDER # 2 3MW BATTERY SYSTEM
BATTERY POWER COMPENSATION ON 11kV NETWORK
Battery Groups
 33 Modules
Battery System.
 2 x 40ft shipping containers
 30kW Cooling each container
 Voltage 750‐1050VDC
 44 Groups – 1452 Groups – 17,424 Cells
Battery Module
 12x Individual Cells
 45Ah
 27.6V
Battery Inverter
 Multiple Inverters
 20ft shipping container
 60kW Cooling

10. BATTERY TEMPERATURE
Battery Temperature Rise – 18 Modules
BATTERY POWER COMPENSATION ON 11kV NETWORK
Battery Temperature Rise – 44 Modules
Increase in Battery groups, less power group utilised, less temperature rise.
Magnitude increase in quantity of batteries increased costs.

11. BATTERY PERFORMANCE
 Requires 4min to recharge for 50% to 90%
BATTERY POWER COMPENSATION ON 11kV NETWORK
CSA Winder Cycle times
 1 Cycle every 5 minutes
 12 Cycles per hour
 Continuous operation
Battery Depth of Discharge
 Can only operate in the 80‐90%
range
 Winder 2: Battery have 85sec
to charge between cycles
Battery Operating Zone 80‐90%

12. BATTERY MANAGEMENT
Battery Management Unit – Key Functions
 Monitors voltage and temperature of individual cells
 Charging and Discharging current‐ disconnection if exceeded
 State of Charge calculations
 Thermal modelling calculations
 Short Circuit protection
 CANbus communications to battery management unit
BATTERY POWER COMPENSATION ON 11kV NETWORK

13. WINDER CONSTANT POWER
Winder #1
Constant power
1.7MW
BATTERY POWER COMPENSATION ON 11kV NETWORK
Winder #2
Constant power
1.5MW
Battery Discharge
Grid Power
Regeneration
Battery Discharge
Grid Power
Constant
Power Line
Constant
Power Line

14. WINDER OPERATIONS v BATTERY PERFORMANCE
BATTERY POWER COMPENSATION ON 11kV NETWORK
CSA Winder Cycle times
 Vey high cycle times with minimal battery rest periods.
 24/7, autonomous operation.
Battery Operations
 Can only operate in the 80‐90% range.
 Large current surges for short periods.
 Heat generation in batteries significant, no time for heat dissipation (I2t).
 Battery quantity (modules) required increases significantly due to battery
thermal requirements.
System Limitations
 Max 20hrs per day.
 Min 4hrs for battery rest time – allow heat to dissipate.
 6 day operation, with 1 full day of battery rest time.
 Will vary with cycle requirements and operational time.

15. OPERATIONAL CONSIDERATIONS
BATTERY POWER COMPENSATION ON 11kV NETWORK
ISOLATION
 CELLS, MODULES, and BATTERY SYSTEM
 Isolation – high power stored energy – 3MW
 High Voltage Systems
 Fault levels – AC and DC
 IP2x considerations
VOLTAGE
 Modules are Low Voltage
 Cells are Extra Low Voltage
POWER SYSTEM
 Fault levels
 Protection‐ individual cell fuses

16. SYSTEM DESIGNS
BATTERY POWER COMPENSATION ON 11kV NETWORK
Winder 1 – Drum Winder
 26 Modules.
 2MW.
Winder 2 – Koepe Winder
 44 Modules.
 3MW.
Design Variations and Limitations
 Battery Rest times.
 Hours of operation per day.
 Rest days.
 Constant load power V Peak load compensation V other design.
All affect the design.

17. SUMMARY
BATTERY POWER COMPENSATION ON 11kV NETWORK
OUTCOMES
 The battery system can provide peak power compensation on dynamic
loads.
 Constant winder power was best option for load profiles. Greater battery
rest times.
 Fixed demand from grid.
 Additional grid power available for other loads.
CAPITAL COSTS
 Grid power lower cost option.
 But not when power constrained on network. Contributions to
network augmentation is significant for power increase.
 Return on investment less than 3 years. No supplementary diesel
generation.

18. QUESTIONS
BATTERY POWER COMPENSATION ON 11kV NETWORK