s

2008 Automation SummitA Users Conference

Expand your world of automation

Presenter:Company:

ID#:2833Title: Active Front End Technology for AC DrivesTrack: Motion ControlTopic:

Craig Nelson

Siemens E&A

page 2

Active Front EndTechnology

For AC Drives

page 3

Typical AC Drive

t

I PhaseV dc

I Phase

t

page 4

AC Drive Using AFE Technology

DC LinkAFE Inverter

L1

L2

L3

t

I PhaseV dc

t

I PhaseV dc

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Advantages with AFE Technology

Line current Line current

0 ,0 %

1 ,0 %

2 ,0 %

3 ,0 %

4 ,0 %

5 ,0 %

6 ,0 %

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

H a r m o n ic O r d e r

Har

mon

ic V

olta

ge L

evel

A c tiv e F ro n t E n d1 2 p u ls e6 p u ls e

Low Harmonics

Current draw from AC drive Current draw from AFE drive

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Advantages with AFE Technology

Power Factor Correction

Leading power factor Unity power factor

The AFE control algorithm adjust the pulse pattern which can be set to leading, lagging or unity power factor

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Advantages with AFE Technology

Voltage Boosting

C

Vdc

Load(motorinvertersection)

S1V

VL

L

I1 I2

Initially C charges to voltage V (pre-charging), I2.

S1 closes and current I1 increases. L stores energy.S1 opens, the energy in L is transferred to C by the current I2. Due to the inductive voltage effect Vdc =V+VL

By controlling the switching of S1 the voltage Vdc is kept constant, independent of the voltage V or the load.The faster the switching of S1 the better the control of Vdc and the smoother I becomes.

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Advantages with AFE Technology

• Power Regeneration (four quadrant)• Highest drive dynamic performance• Reduce product variances• Increased motor utilization• Increased efficiency• High availability even on weak networks• Fulfill toughest specifications• Widest supply range• Ideal solution for multi-axis system

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Considerations with AFE Technology

• Upfront cost• Noise• Added complexity• Reduced impact for small HP

Vac in

3M~3

Clean Power Filter

Intelligent switching behavior

AFE

M~

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What do AFE‘s Look Like?

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Typical AFE Applications

Motion Control

Rotary press

Paper mills

Rolling mills

Mining

Test Stands

Winders

Amusement Rides

Centrifuges

Shears and Cutters

Marine

Crane and Hoist

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Open-cast miningSINAMICS S150 in a bauxite mine

Instead of slipring rotor motors, now, low-maintenance SINAMICS S150 drives control the conveyor speed. This improves the starting behavior therefore reducing the stress on the complete conveyor system, ensures more efficient conveying operations and saves energyWith its Active Infeed technology, when the conveyor belt brakes, SINAMICS S150 regenerates the energy back into the line supply, minimizes the harmonics fed back into the line supply and makes the drive system insensitive to fluctuations in the line supply voltage

Solution

Alcan inc.

Application:Modernization of the conveyor systems in the bauxite mine. The customer specified improved starting characteristics, higher conveyor capacity and lower operating costs

Application Customer

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Food & Beverage industrySINAMICS S150 for sugar centrifuges

A total of 33 SINAMICS S150 with power ratings from 200 to 315 kW optimally control the extremely sophisticated sugar centrifuging process with maximum dynamic performance and precision – and that with the highest possible degree of availabilityWith its Active Infeed technology, SINAMICS S150 reduces the harmonics fed back into the line supply to a minimum and makes the drive system insensitive with respect to fluctuations in the line supply

Alto Alegre Sugar & Alcohol ind.

Application:Operation of sugar centrifuges. During the 3-months campaign, 24 hour operation every day (7x24); continuous and fast ramp-up and ramp-down; operation into the overload range

Solution

Application Customer

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Marine engineeringSINAMICS S150 for pipe and cable laying ships

In the meantime, 12 SINAMICS S150 drives with power ratings from 250 to 400 kW optimally control the pipe laying machines and winches with maximum dynamic performance and precision - with the highest degree of reliability even under conditions typical for shipboard applicationsWith its Active Infeed technology, SINAMICS S150 reduces the harmonics fed back into the line supply to a minimum and makes the drive system insensitive to fluctuations in the line supply

REMACUT s.r.l.

Application:Reliable operation of pipe and cable laying machines under conditions typical onboard ships -such as high vibration levels, high temperatures and unstable line supplies

Solution

Application Customer

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Conclusion

Driving Forces for AFE Drives:

1. Power cost have increased dramatically2. Utility companies are tracking harmonics and power factor more closely3. Mechatronics has increased drives applications for motion control4. OEM’s demanding higher performance for increased machine capacity5. Copper prices are driving up the cost of transformers and conductors6. Companies are being pressured to “think green”7. More drive venders are offering AFE drives in increasing ranges.8. Prices of AFE drives have been driven down by competition9. AFE technology is now better understood and accepted10. New generation of Active Front End drives are more user friendly

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Siemens Innovations in Motion Control