MEMSA Presentation June 12, 2014 Managing Power … · MEMSA Presentation June 12, 2014 Managing Power Demand on Excavators ... • Electric Rope Shovels have a very high rate of

MEMSA Presentation June 12, 2014

Managing Power Demand on Excavators

Craig V Fredrich– Engineering Technical Steward

Caterpillar Global Mining

ERS / DGL Product Group

2 / Caterpillar Confidential: GREEN / WHEREVER THERE’S MINING

Contents

Safety

Introduction

Caterpillar AC History

Robust Power Requirements

Power Demand Management

Summary

Questions

3 / Caterpillar Confidential: Green / WHEREVER THERE’S MINING

Safety


Safety First, Safety Always

Emergency Phone Numbers

• Fire Emergency:

• Call 911

• Medical Emergency:

• Call 911

• CPR/AED Certified?

• Who will call emergency numbers?

• Room Hazards - Chairs

• Location of Exits

• Nearest Fire Extinguisher

• Nearest AED

• Evacuation Point



Introduction


Craig Fredrich

• Electrical engineer

• 28+ Years Mining experience

• Started in field service working on SCR based analog

machines

• Have been with the progression of the drive systems to the

present IGBT digital controls


Caterpillar AC History


Bucyrus forms alliance with Siemens.

Bucyrus introduces “Analog SCR” AC Drives

Electric Rope Shovels Small Draglines

Bucyrus introduces “GTO” AC Drives

Electric Rope Shovels Small Draglines Large Draglines (Swing)

Bucyrus introduces “IGBT/AFE” AC Drives

495BII Large Draglines (Swing)

Bucyrus develops first AC IGBT/AFE Gearless

8750 Zhungeer (CHINA)

Bucyrus AC IGBT/AFE Conventional Geared

8750 Lake Lindsay (AUS) 8750 TAU (CAN)

Bucyrus AC IGBT/AFE Conventional Geared

8200 Reliance (INDIA) 8200 Reliance (INDIA)

1976 1980 1989 1999 2003-04 2006-07 2010-14

37 YEARS CATERPILLAR AC EXPERTISE


IGBT AC Drive Systems

180 plus machines approaching 8,000,000 operational hours

IGBT powered Electric Rope Shovels operating since 1999

5 machines approaching 200,000 operational hours IGBT powered Draglines operating since 1999

2 new machines IGBT powered 8200 Draglines go to work 2014




• Electric Rope Shovels have a very high rate of change in

power demand

• To reduce energy costs, rope shovels also regenerate

electricity back onto the line


• A robust power system is

required to manage both

the regeneration and the

high ramp rates

• These requirements

provide challenges for

Diesel power systems



• Rope shovel rate

of change are 2 to

3 times faster than

a typical Diesel

generator can

provide

• To protect the

generator from

regeneration,

resistive load

banks burn off

excess energy



How it Works

Power Demand Management – How it works

Peak Shaver

Shaves peak demand by using

energy stored in ultra capacitors

Ramp Rate Limiter

Redistribution of power for ideal

genset loading

Power supplied by ultra caps

Power stored in ultra caps

Dig Swing & dump Lower


Electric Rope Shovel Typical Power Demand


Power Requirements with Power Management System

Ramp Rate Limiter

Redistribution of power for

ideal genset loading

Peak Shaver



Regeneration

Recharge ultra-capacitors with

energy from stopping motions


Power Demand Management - On-Grid

Intellectual Property – Power Demand Management

• U.S. Patent No. 4,358,719

• U.S. Patent No. 8,174,225

• U.S. Patent No. 8,536,814

• Future Patents Pending


8750-81 Dragline 8-8-10 Typical KW vs Time curve


8750-81 Dragline 8-8-10 Typical KW vs Time curve

Peak Shaver




Power Demand Management Overview


Caterpillar Exclusive Technology

Off-Grid Benefits

• Most efficient off-grid power solution available

– Shovel operational on 4MW of genset power for reduced fuel consumption compared to traditional method of operating with 8MW of power or more

• Patented technology manages energy

– Rope shovel regeneration power utilized not wasted

• Sustainable solution

– Reduced greenhouse gas emissions

– Less wasted energy

Additional Benefits after Power Grid is in place

• Trail cable flexibility – longer trail cable runs

• Substation sizing – reduced power infrastructure costs

Cat® Power Demand Management Technology


Power Demand Management – Trail Cable Sizing

Longer trail cable* allows for more flexibility when placing substations

• Keep substation out of the pit

• Less hassle relocating during laybacks

• Remove the need to run high tension cable in the pit

*Trail cable length is dependent

upon many factors, including

voltage drop of the transformer and

overhead line.


Demonstrations at Tucson Proving Grounds



Building Blocks


System Components

Incoming

Power

Transformers AFEs Inverters

Hoist

Propel

Crowd

Swing

Chopper Energy Storage


Equipment Pictures


MRC Features

Durable / Resilient Cabinets

Durable welded steel construction Designed for ERS shock and vibration

environment

All components in cabinet are accessible for maintenance

Degree of protection

Ventilated section IP21 in acc IEC 529

Non-ventilated section IP54 in acc IEC529

Ambient temperature

Normal Operation -40 °C to + 50 °C

Storage & Transportation -40 °C to +70 °C

Integrated and independent liquid cooling system

Integral propel Transfer Switch


AC Power Module Building Blocks

Dragline Skid Configuration Space for up to four AFE rectifiers

Common DC bus

Connects AFE with inverters

Space for up to five motor inverters

to power

Maximum one 824AC hoist motor

Maximum one 824AC drag motor

Maximum one 822AC swing motor

Conventional 1370W (4-4-4)

Powered with 4 MRCs

Conventional 8750 (8-8-8)

Powered with 8 MRCs

M

Swing Motor 1

M

Hoist Motor1

M

Drag Motor 1

M

Propel Motor 1

Swing

Inv 1

Hoist

Inv 1A

Drag

Inv 1A

Hoist

Inv 1B

Ground

Fault

ProtectionCrowbar

DC Link Capacitor

Precharge

Transformer

Delta / Wye

Aux Power

AFE 1 AFE 2 AFE 3 AFE 4

T T T T

Drag

Inv 1B



Power Problems / Application


Genset Challenges

• Regen Absorption

– Avoid engine overspeed

• Peak Power Limiting

– Limit engine sizing

• Rate of Change

– Match engine dynamic response

• Application without Peakshaving can require double the

number of gensets needed with peakshaver


Mine Power Considerations

• Unstable Power

– Mines experience machine downtime or component failure due

to insufficient or unreliable power infrastructure

• Delayed Power Plan

– Delays in the mine power plan cause delay in machine

production

• Pit Expansion

– Expanding to an area of the mine that does not have electrical

infrastructure


Mines have limited options for loading tools when opening

a new pit until electrical infrastructure is in place at the pit

Greenfield Mine Application

• Diesel-powered machines are typically employed for initial

overburden removal

• Operating electric rope shovels on

Diesel-generators is generally not

economical due to the machine’s

excessive rate of change in power

demand, unless peak shaving

technology is employed

• Electric rope shovels also regenerate

electricity, which can not be absorbed

by generators and must be absorbed

by PDMS or burned off via load banks


Pros

+ Flexibility / Utility

+ Lower Initial Capital Cost per machine

Mine Development with Diesel-Powered Machines

Power Grid

Complete

Pre-Stripping Production

Cons

- Higher Cost / ton

- Lower NPV

- Higher Total Cost


Pros

+ Lower Cost / ton

+ Longer machine life

+ Backup Generators

+ Best TCO

Mine Development with Power Demand Management

Power Grid

Complete

Pre-Stripping Production

Cons

- Higher Initial Capital Cost

- Generator Cost


Holistic Machine Approach


Holistic Machine Approach

CAT Total Machine Commitment


Holistic Approach Examples

• House Ventilation Study

• Propel Study

• Roller Load Study

• Stability Study

Questions?

THANK YOU


Close

Thank You For Your Participation

MEMSA Presentation June 12, 2014 Managing Power … · MEMSA Presentation June 12, 2014 Managing Power Demand on Excavators ... • Electric Rope Shovels have a very high rate of

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