RTG & VSG Presentation

EGSA ConferenceSept. 18, 2006

Alan McDonnell Bill YoungSales Manager PresidentYoutility Inc. Industrial Power Systems Inc.11 Executive Dr. Hudson, NH 03051 3010 Powers Ave. Jacksonville, FL 32259

INDUSTRIAL POWER SYSTEMS, INC

VSG – Fixed Speed Comparison

• The following slide shows a comparison between the fixed speed power generation model and a variable speed industrial model CAT C32 ACERT, one of their newest electronic engines

• Both engines meet EPA Tier 2 emissions

Total Fuel (lb-hr)

Power (kWe)

1000600200 400 800

500

300

200

100

400

100

1800 RPM vs. 700-2100 RPM

100%

50%

110%

1000600200 400 800100

Maximum TorqueMode

Expected MaximumEfficiency Mode

Output (kWe)

Fixed Speed Fuel Consumptionvs. Variable Speed

Economical Applications of VSG

• The economics of adding the VSG system will be better for applications with low average power demands

• Cranes that require full power for only short periods of time while lifting are good candidates

• With a VSG installed, the engine will idle most of the time, and increase in speed only when needed

IPS and Youtility

• Have designed a system that can be easily retro-fitted to existing RTG Cranes

• Several hundred existing cranes in service globally

• Youtility supplies electronic equipment, design responsibility and support to IPS

• IPS builds necessary electrical equipment, installation and project management

Typical RTG (Rubber Tire Gantry)

Basic VSG Diagram

VSGControl

ACSupply

Ultra-cap

Variable SpeedGenerator

Crane ACpower feed

800VDC

400 - 720VDC

290VAC - 36Hzto

480VAC - 60Hz

Detailed VSG Diagram

Pre-ChargeContactor

(+)

(-)

Rectifier Boost

OutputAC Inverter

Bypass / Isolation Contactors -Interlocked

Energy Store / ReleaseChopper control

Generator250kVA200kW480V

1800RPM

N

6.7L

153kW

EnergyStorage

Variable DC

Regulated 800VDC

Unique Features of Crane Electrical Power Requirements

• New Cranes use AC VFDs to power motors, the major loads (90%)

• AC VFD consists of a DC rectifier feeding DC power to an AC inverter

• Since the VSG also makes DC power, it can be fed directly on a “common DC bus”

VSG with common DC bus

VSGControl

AC VFDs

ACSupply

Ultra-cap

M M M

Variable SpeedGenerator

aux. loads

800VDC

400 - 720VDC

480VAC - 60Hz

290VAC - 36Hzto

480VAC - 60Hz

Detailed crane DC bus unit

Pre-ChargeContactor

(+)

(-)

Rectifier Boost

OutputAC Inverter

Bypass / Isolation Contactors -Interlocked

Energy Store / ReleaseChopper control

Generator250kVA200kW480V

1800RPM

N

6.7L

153kW

EnergyStorage

DC Bus powerconnection

Variable DC

Regulated 800VDC

Energy Storage Advantages

• Engine produces poor step change power at low speeds

• Energy Storage can supply full rated power in less than 4mSec. With DC/DC boost circuit

• Energy Storage can reclaim energy that otherwise goes to Dynamic Braking Resistors

• Energy Storage can “smooth” the power required from the generator, less peak required…therefore smaller generator

• For high cyclic loads, we prefer Ultra-Capacitors over batteries

A Maxwell brand Ultra-Capacitor

Energy Storage Calculations

• 48V x 144F each bank

• 16 banks in series = 768VDC x 9F

• Total energy = ½ * c * V 2 = 2.6MJ

• Useable energy = 0.7 x 2.5MJ = 1.75MJ

• Need 400kW (peak) – 150kW (engine) = 250kW x 7sec. = 1.75MJ

RTG Crane Expectations

• Overall Fuel Consumption reductions of 30% -50%

• Total Emissions reductions of 70% - 90%

• Reduce 23L engine to 6.7L engine

• Reduce Idling Fuel Consumption from 20+ L/hr. to 2 L/hr.

• We predict all future cranes will be VSG in less than 2 years, based on market competition

Other VSG Applications

• Most economical for variable load or less than full load applications

• Grid Connect, Stand Alone or Parallel Unit Operations

• Combined Heat-Power total efficiency for part-load conditions is much improved

• High power quality requirement applications

Other VSG System Features

• Transformerless output with full unbalanced load capabilities

• Synchronous Generator with integral field control, no need to use a different generator

• 96%+ pf. on generator, allows higher outputs with full VA rating utilized

• Integrated Energy Storage allows full step load changes in ¼ cycle, no freq. deviation

End of Presentation

• Bill YoungIndustrial Power Systems, Inc.

• Alan McDonnellYoutility Distributed Power Electronics