2012 PowerPoint Template

Multi-Level Approaches for

Mitigating Power Quality Issues

Mark Stephens, PE, CEM, CP EnMS-Industrial

[email protected]

Electric Power Research Institute

SEEDZ Power Quality Workshop Part 2

Moffett Park / North Bayshore

Smart Energy Enterprise Development Zone

mailto:[email protected]

2 © 2013 Electric Power Research Institute, Inc. All rights reserved.

Mitigation Levels


Example PQ Solution Levels

Machine or Subsystem Level

Power Conditioning

Control Level

Power Conditioning (1/10th to 1/20th of Machine Level Power Conditioner Cost)

Control Level

Embedded DC Solution (Best done by OEM in design phase)


New Solution for an Old Problem:

EPRI Nice Cube Block Concept & Prototype

Original “AC Ice Cube”

Drop out ~70% Vnom

Remove “AC Ice Cube” Insert

“Nice Cube” Puck Into Base

Insert “DC Ice Cube”

Drop Out ~ 25-30% Vnom


Example Nice Cube Application

Pellet Bin ExtruderMetering

PumpRoll Stand 1

Roll Stand 2 Roll Stand 3 Roll Stand 4 Winders

Line E-Stop Relays

Legend:

Potential AC “Ice Cube” Relay Location (Depends on Line)

DC Extruder Drive

AC Drive

Rheostat Controlled AC motors (No PQ Issue)


Example Nice Cube Installations


PQSI “Nice Cube” Vs. Typical AC “Ice Cube”:

Plotted Against Sample PQ Data


White Paper


White Paper (continued)


Uninterruptible Power Supply (UPS)

Battery Based

UPS

Are Often

“Overkill”

For Control Loads

Small 500Va to

3kVA

UPS Systems are

sometimes Used

“Abandoned in Place” UPS Systems:

A Common Problem


DC UPS for DC Power Supplies

Battery

DC UPS

DC Power

Supply Load

• If minutes of ride through is needed a DC UPS will be necessary.

• The difference between a buffer and a UPS is the UPS provides battery management circuitry for high capacity battery banks.

• These systems typically provide the same feedback features as the buffer module discussed in the previous slide.

Ref: Mean Well DR-UPS40 data sheet


Example PQ Mitigation Devices

1 f f - f 3 f

3f ProDySC 0% / 2 sec. 30% / 2 sec. 50% / 2 sec. at full load

45% / 30 sec. 45% / 30 sec. 50% / 30 sec.

25% / 30 sec. 25% / 30 sec. 50% / 30 sec.

1f Contrl Ckt PowerRide RTD 0% / 2+ sec.0% A-B, B-C; 70-

80% C-A / 2+ sec.70-80% / 2+ sec. 3-phase Input, 1-phase Output

1f Contrl Ckt MiniDySC0% / 0.05 sec.

50% / 2 sec.n/a n/a

1f Contrl Ckt CVT 40-50% / 2+ sec. n/a n/a

1f Contrl Ckt VDC (6T Model) 37% / 2+ sec. n/a n/a

1f Contrl CktCoil Hold-in (CoilLock

and KnowTrip)25% / 2+ sec. n/a n/a for relays, contactors, motor starters

3fAVC (two rated

models)at full load

Comparison of Power Conditioning Devices

Coverage (Vnom) / DurationApplication Device Notes

3f

3f

1f

1f

1f

1f

1f

1 f f - f 3 f


Generalized Example:

Control Level to Equipment Level

Cost vs. Coverage

+

+


Example Control Level Solution

Application

• The CVT is protecting only the

AC control components means

that the selected power

conditioner will be more

affordable than one that could

protect the entire machine.

• The ride-though of the AC

drives in this example can be

enhanced by modifying their

programming, thus eliminating

the need for a large power

conditioner.


Solution Application Points

• Voltage Sags may be mitigated at a variety of locations

• Service Entrance, Panel Feeder, Panel, Machine, and Control Levels.

Example Network:


• AB PLC 5

– 78% Vnom

– Remote rack – 72% Vnom

• Idec RY4S – ac “Ice Cube” relays

– ~70% Vnom RR3B

AB

Example Problem – Multiple Cabinets Fed from Centralized Control Power Panels


Example Solution: Distribution Panel Level Mitigation

• Remove abandoned UPS and use UPS bypass switch already in place

• Four distribution panels in room for Extruder lines plus one additional for other related control loads (5 total)


Another Distribution Panel Example

• Sometimes the most effective

solution is to provide

conditioned power for the entire

IPP Panel. Advantages of this

approach include:

– Simplified Cut Over/Fewer

Touch Points

– Single Power Conditioner for

many loads

– When sized to support kVA

of transformer, this approach

will support future expansion

in panels

3-Phase

480Vac

Power

Conditioner

Xformer

480/208

3-Phase

30kVA

IPP-PC

480Vac

3-Phase

MCC Bus


Example Measured Loading of IPP Panel

• Panel Lightly Loaded

– Several Spare CB in Panel

– 480Vac CB Rating is 50A

– 480Vac Phase Currents

• Phase A – 4.89A

• Phase B – 4.11A

• Phase C – 1.67A

• Measurements were taken when

line was running.

• It is possible that some loads

could be cycled off.


Example Series Boost Mitigation

Input Voltage

Missing Volts

DySC Output Voltage

DySC

AVC


Example Three Phase Solution – ProDySC

• The Dynamic Sag Corrector

from Softswitching Technologies

• Deep Sag Coverage especially

when lightly Loaded

• Has Capacitors that allow for

some ride-through for

interruptions


Example Three Phase Solution – AVC

• Three-Phase Correction to

50%

• Single-Phase Correction to

25%

• No capacitors, therefore no

deep sag or interruption ride-

through


Example Control Level Option

(Area Wide Power Distribution for CPT Primaries)

• Fewer, larger sag mitigation devices

– Fewer touch points but more expensive mitigation devices

– New 480Vac Panel, new conduit and wiring to machine controls

– Labor costs


Feeder Level Mitigation Scenarios

• Multiple very large sag

mitigation devices

– Fewer installation points, less

wiring, conduit, & labor

– Higher Equipment Costs

– More Comprehensive

Coverage

– Some Typical Voltage Sag

Solutions

• Omniverter AVC

• Softswitching DySC


CAT UPS – Machine or Feeder Level

• Flywheel speed 8000 RPM. In recent years there has been a number of installations in US for bridge power application; provides 15 second protection under rated load condition.


CAT UPS Performance from Test in EPRI Lab


Static Transfer Switch

• Solid State thyristor or GTO switches

transfer between independent

distribution sources for interruptions

and sags

• 1/4 to 1/2 cycle response

• medium voltage, 600 A

• no energy storage

• electronics require cooling

• ~ $350k to $700k each


Series Voltage Boost Devices

• Synthesizes missing part of waveform

• Medium voltage applications, up to 40 MVA

• May contain energy storage, usually DC capacitors

• Ride-thru for 0.2

to 1.0 sec

• 1/4 cycle response

• Up to 60% boost

• ~$600K per boost

MVA


Conclusions

• It’s a team effort to solve these problems, the utility, industrial, and sometimes consultants need to come together.

•Understanding why your equipment is vulnerable is paramount. You can’t fix a problem without understanding the true cause.

•Moving forward (sometimes with some simple modifications) you can make industrial systems more robust. Don’t forget including PQ standards in your purchase specs.

• Don’t assume battery based systems are required. Smaller solutions may be more cost effective.


For More Information Contact:

Mark Stephens, PE, CEM, CP EnMS - Industrial

EPRI | Senior Project Manager

Industrial PQ & Energy Efficiency

942 Corridor Park Blvd, Knoxville, TN 37932

Desk: 865-218-8022

Mobile: 865-773-3631

www.epri.com

http://f47testing.epri.com

http://mypq.epri.com

[email protected]

http://www.epri.com/

http://f47testing.epri.com/

http://mypq.epri.com/

mailto:[email protected]

Documents

2012 PowerPoint Template