TROLLEY ASSIST TO OPTIMISE HAULING CYCLES WITH ELECTRIC TRUCKS

By

Vicente E. AlvaradoPlanning and Development EngineerGrootegeluk Coal Mine

PURPOSE OF THE PRESENTATION

This presentation discuss the basic analytical tools required to evaluate the feasibility of the application of TROLLEY ASSIST to mining hauling cycles.

By applying trolley assist, open cast mining activities may save up to 50% in the fuel cost and improve the productivity of the fleet by 10% or more

INTRODUCTION

TROLLEY ASSIST : What is it?

An engine drives the alternator to generate power on board of

the truck. The power is chenneled to the wheel motors

Power is collected from a DC overhead line by means of

pantographs. The line propels the truck. The engines just

idle along

Power Capacity in a 185 Tonne Truck:Engine : 2000 HPWheels Motors : 3100 HP

COMPARATIVE DUTY Accelaration On Flat On ramp Diesel Retarding Trolley

ENGINE Heavy Mild Heavy Low Low

WHEEL

MOTOR

Mild Low Mild Heavy Heavy

THE OVERHEAD LINE

The overhead line consists of galvanised mast poles positioned at a maximum distance of 50 m apart. The line is strung with grooved contact wire, which may be fixed directly to the poles by means of insulated brackets or may hang from a messenger cable, which is fixed to the poles by means of insulators.

THE TRACTION RECTIFIERS

The rectifiers are sized to supply one truck permanently. In this way, the number of trucks to be connected simultaneously to the line determines the number of rectifiers to supply a specific line. This distributed scheme reduces the possibility of overloading the contact wire and reduces the voltage fluctuations experienced by the truck

0

250

500

750

1000

1250

1500

j

1500

1540

1580

1620

1660

17000

1000

2000

3000

4000

5000

6000

0 100 200 300 400 500

Time [se]

DC

Cur

rent

[Am

ps]

0

1

2

3

4

Num

ber o

f Tru

cks

THE PERFORMANCE PARAMETERS OF THE TRUCK

Speed → Productivity Rate of Fuel Consumption → Hauling Cost

Energy Utilisation Rate → Cost of Use of Electric Energy } They depend on the operational

conditions of the truck

Loading

Flat

Flat

Flat

Flat

Diesel

Trolley

Retarding Empty

Tipping

Retarding Loaded

TRUCK SPEED

Motor Torque Curves - EH4500

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

22000

24000

26000

0

200

400

600

800

1000

1200

1400

1600

1800

2000

2200

2400

2600

2800

3000

3200

3400

3600

Propel, DieselRetard, NormalPropel, Trolley10% Grade

Motor Speed [ rpm ]

Mot

or T

orqu

e [

ftlb

]

Euclid-Hitachi/Siemens AC Haul Truck Drive

DC Link Voltage, (on Trolley): 2200 V @ 1500 A(max)

Truck : EH4500Electric Drive : Siemens AC DriveGross Weight : 960 000 lbPayload : 255.4 TonneRolling Radius : 67.2 inGear Ratio : 35.816Engine GHP : 2700Grade : 8% Ramp + 2% RR

960000 lb • 10% • 67.2 inMotor Torque = ———————————— = 7505 ft lb

2 • 12 in/ft • 35.816

800 rpm • 60 min/hr • 2 • π • 67.2 in Truck Speed in Diesel = ——————————————— = 14.1 KPH

35.815 • 39380 in/Km

1450 rpm • 60 min/hr • 2 • π • 67.2 in Truck Speed in Trolley = ——————————————— = 26.1 KPH

35.815 • 39380 in/Km

FUEL CONSUMPTION RATE

In trolley mode, the engine normally idles at about 750 rpm. In that condition, the load on the engine is mainly the cooling blower of the electrical system. This load is normally about 10% of the gross capacity of the engine.

In diesel propulsion on a 10% effective grade, the engine will develop full power at maximum speed. In the case of the 12V 4000 engine, this is 2025 BHP at 1900 rpm.

ENGINE IN TRUCK 730E

0.33 lb/BHP-Hr • 2025 BHPFuel Rate in Diesel = ———————————— = 360 LPH

1.86 lb/L

0.41 lb/BHP-Hr • 2025 BHP • 10%Fuel Rate in Trolley = ————————————— = 45 LPH

1.86 lb/L

Energy Utilisation in Trolley

For the EH4500 truck, the maximum line voltage is limited by the capacity of the system specified by Siemens at 2400 volts maximum at the DC link of the drive. The current is limited at 1500 A. Therefore the estimated energy utilisation of the EH4500 truck in trolley mode is 3600 kW.

730E Truck Motorised Wheel Curves

For the 730E Truck:

Energy Utilisation = 1600 * 1450 / 1000 = 2320 KW

Truck Performance Measurements

-2000

-1500

-1000

-500

0

500

1000

1500

2000

1 1448 2895 4342 5789 7236 8683 10130115771302414471

Volts

- A

mps

- LP

-48

-36

-24

-12

0

12

24

36

48

KPH

MW current in Amps

Trolley cur in Amps

Trolley volt in volt

Fuel cons. in LPH

Idling

Truck speed in Km/h

Window Trolley

Window Retarding

Ramp Diesel

On Flat

Truck 25343 Performance Test

Type: Komatsu 730ECapacity: 185 TonGVW: 324.3 Ton

Truck PerformanceOperation Index Unit Test 1 Test 2 Test 3 Test 4

Complete TestDate 01/08/2002 01/08/2002 01/08/2002 01/08/2002Start 12:25:28 9:56:04 10:31:16 11:01:46Finish 12:44:58 10:28:08 10:57:45 11:37:20Duration 0:19:30 0:32:04 0:26:29 0:35:34Fuel Used Lts 42.91 37.38 34.63 44.66Travel Km 9.075 7.921 7.660 8.252

Acceleration Time sec 93.7 88.6(Fully Loaded) Total Fuel Lts 4.13 4.35

Travel Km 0.756 0.592

Idling Time sec 885.1 625.7 1060.9Fuel Consump Lts 5.08 4.32 8.23Av. Fuel ConsumpLph 20.67 24.86 27.92

On Flat Road Time sec 341.1 293 357.9 402Fuel Consump Lts 14.54 11.07 14.64 16.51Travel Km 3.460 3.026 3.728 4.218Av. Fuel ConsumpLph 153 136 147 148Av. Truck Speed Kph 36.5 37.2 37.5 37.8

On Ramp Diesel Time sec 78.3 44.4 22.2 40.8Fuel Consump Lts 8.03 4.57 2.25 4.04Travel Km 0.429 0.236 0.112 0.196Av. Fuel ConsumpLph 369 371 364 357Av. Truck Speed Kph 19.7 19.1 18.1 17.3

In Trolley Mode Time sec 89.2 178.9 146.1 140.4Fuel Consump Lts 1.25 1.69 1.16 1.50Travel Km 0.602 1.248 1.029 0.919Energy KWHr 52 102 78 79Av. Fuel ConsumpLph 50 34 29 39Av. Truck Speed Kph 24.3 25.1 25.4 23.6Av. Energy UsageKW 2085 2050 1923 2024

In Retarding Time sec 258.3 214.6 162.6 149.1Fuel Consump Lts 2.71 2.41 1.90 1.81Travel Km 1.358 1.717 1.412 1.222Av. Fuel ConsumpLph 38 40 42 44Av. Truck Speed Kph 18.9 28.8 31.3 29.5

Loaded Empty

Performance Test on 730E Truck

EVALUATION OF THE TROLLEY ASSIST SYSTEM

Payload 185 Tonne

Condition Idling Flat road On Ram p DiesIn Trolley ModFlat road Idling Flat road Retarding Flat road CycleLoading Loaded Loaded Loaded Loaded Tipping Empty Empty Empty Summary

Distance in [m] 800 400 1000 200 200 1400 200

Perform ance with TrolleySpeed [KPH] 0 35.1 12.2 23.7 35.1 0 35.1 26.4 35.1Fuel Rate[LPH 30.2 144.1 367.0 37.4 144.1 30.2 86.4 44.2 86.4E. Rate [KW] 0 0 0 1930 0 0 0 0 0

Tim e [sec] 360 82 118 152 21 300 21 191 21 1265Fuel [Lts] 3.0 3.3 12.0 1.6 0.8 2.5 0.5 2.3 0.5 27Energy [KWHr 0 0 0 81.5 0 0 0 0 0 82Truck Productivity TPH 527

Perform ance only in DieselSpeed [KPH] 0 35.1 12.2 12.2 35.1 0 35.1 26.4 35.1Fuel Rate[LPH 30.2 144.1 367.0 367.0 144.1 30.2 86.4 44.2 26.5E. Rate [KW] 0 0 0 0.0 0 0 0 0 0

Tim e [sec] 360 82 118 295 21 300 21 191 21 1408Fuel [Lts] 3.0 3.3 12.0 30.1 0.8 2.5 0.5 2.3 0.2 55Energy [KWHr 0 0 0 0.0 0 0 0 0 0 0Truck Productivity TPH 473

EVALUATION OF THE TROLLEY ASSIST SYSTEM

Payload 255 Tonne

Condition Idling Flat road On Ram p DiesIn Trolley ModFlat road Idling Flat road Retarding Flat road CycleLoading Loaded Loaded Loaded Loaded Tipping Em pty Empty Em pty Summ ary

Distance in [m] 800 400 1000 200 200 1400 200

Performance w ith TrolleySpeed [KPH] 0 36.1 16.0 31.5 36.1 0 36.1 27.0 36.1Fuel Rate[LPH 34.0 199.9 499.8 46.4 199.9 34.0 119.9 30.5 119.9E. Rate [KW] 0 0 0 3377 0 0 0 0 0

Time [sec] 360 80 90 114 20 300 20 186 20 1190Fuel [Lts] 3.4 4.4 12.5 1.5 1.1 2.8 0.7 1.6 0.7 29Energy [KWHr 0 0 0 107.3 0 0 0 0 0 107Truck Productivity TPH 771

Performance only in DieselSpeed [KPH] 0 36.1 16.0 16.0 36.1 0 36.1 27.0 36.1Fuel Rate[LPH 34.0 199.9 499.8 499.8 199.9 34.0 119.9 30.5 18.3E. Rate [KW] 0 0 0 0 0 0 0 0 0

Time [sec] 360 80 90 225 20 300 20 186 20 1301Fuel [Lts] 3.4 4.4 12.5 31.2 1.1 2.8 0.7 1.6 0.1 58Energy [KWHr 0 0 0 0.0 0 0 0 0 0 0Truck Productivity TPH 706

THE RELIABILITY OF THE SYSTEM

Haulpak 730E Euclid EH4500 Euclid EH3500 Total P. FleetTotal Actual Util Total Actual Util Total Actual Util Total Actual Util

Aug-08 8019104 6174416 77% 746419 508819 68% 4397335 3430061 78% 13162858 10113296 77%Sep-08 7856927 6275095 80% 1011703 742567 73% 3960866 3191251 81% 12829496 10208913 80%Oct-08 6140578 4912127 80% 1005292 741819 74% 3602549 2878114 80% 10748419 8532060 79%Nov-08 6928293 5701496 82% 696260 501402 72% 3897195 3217586 83% 11521748 9420484 82%Dec-08 9163884 7296450 80% 1670151 1153852 69% 4466117 3431860 77% 15300152 11882162 78%Jan-09 9657243 7750729 80% 2182507 1521806 70% 5138075 4167920 81% 16977825 13440455 79%Feb-09 6744504 5685332 84% 1665515 1268863 76% 4160781 3525916 85% 12570800 10480111 83%Mar-09 6477716 5501435 85% 1675983 1242466 74% 3640241 3059834 84% 11793940 9803735 83%Apr-09May-09Jun-09Jul-09

Dispatch PowerView® - Panto Utilization (Fleet)

TROLLEY UTILISATION AT GROOTEGELUK MINE

60%

70%

80%

90%

100%

Aug-

08

Sep-

08

Oct

-08

Nov

-08

Dec

-08

Jan-

09

Feb-

09

Mar

-09

Apr

-09

May

-09

Jun-

09

Jul-0

9

CONCLUSION

THANK YOU VERY MUCH