Revision of the CBEMA CurveRevision of the CBEMA Curve

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Control System TestingIndividual Component Sag Test Results

Programmable Logic Controller, 47%

24 Vdc Instrument Power Supply, 70%120 Vac DPDT Relay, 75%

Photo Eye (Emergency Stop), < 1cyc X 87%2

cycl

es

9.2

cycl

es

37 c

ycle

s

time (cycles)

Equipment PerformanceEquipment Performance

System Compatibility System Compatibility AssessmentAssessment

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Programmable Logic Controller, 47%

24 Vdc Instrument Power Supply, 70%

120 Vac DPDT Relay, 75%

5 events persite per year

10 events persite per year

15 30 60 96 128 160 320 480 640 800 960 2880 4800

20

30

40

50

60

70

80

90

10

Duration (milliseconds)

20 events

15 events

Semi Equipment ToleranceSemi Equipment Tolerance

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ge0.2 0.50.1 0.10.05

Duration of Voltage Sag in Seconds

100

90

80

70

60

50

40

30

20

10

0

Semiconductor Equipment Voltage Sag Ride-Through Capability CurveNote: Equipment must continue to operate without interrupt during voltage sags above the line.

Relative Costs for PQ SolutionsRelative Costs for PQ Solutions

Cost versus Benefit AnalysisCost versus Benefit Analysis

Commonly Commonly Used Power Used Power Correction Correction DevicesDevices

Practical ExamplePractical Example

! Facility experiences dropouts each time a thunderstorm rolls through the area

! Estimated number of events impacting production 10 to 15 per year

! Estimate cost per event 20 to 30 thousand dollars! What systems are impacted?

! HID lighting! Air Handling Processes! Programmable controllers! Miscellaneous other equipment

EPRI Portable Sag GeneratorEPRI Portable Sag Generator

Why Do Chillers, Motors, Pumps and Other Why Do Chillers, Motors, Pumps and Other Processes Shut Down When the Lights Blink?Processes Shut Down When the Lights Blink?

Contactor2 cycles,

49%

EMO Relay(next gen)0.5 Cycles,

78%

Main Contactor2 cycles,

43%

EMORelay

1 cycles,52%

EMO Relay0.5 cycles,

61%

EMO Relay1 Cycle

45%

Not Shown:EMO Relay 1 Cycle, 38%

Emergency Off (EMO) CircuitEmergency Off (EMO) Circuit(Simplified)(Simplified)

Q1. What happens if the EMO relay or Main Contactor are extremely vulnerable to voltage sags?Q2. What if the plant voltage is low?Q3. What if the transformer rated output voltage does not match the relay and contactor?

0

5

10

15

20

25

30

0 5 10 15 20 25 30 35

Duration

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TYPICAL SAG AND INTERRUPTION RIDE THROUGH PERFORMANCE CURVE

3cy 5cy 8cy 3 sec

Coilock holds contacts closed for sags above the line

Coilock allows the coil to de-energize in this areato insure that E-stop circuits operate as intended

Contactor HoldContactor Hold--in Circuitin Circuit

Contactor Hold in DeviceContactor Hold in Device

! Designed to let contactor, relay, and solenoid coils energize and stay energized unless input voltage is interrupted

! About the size of a small “Ice Cube” relay! Also provides surge protection for the coil! Designed to specifically work during voltage sag

conditions but to allow the coil to de-energize during interruptions so that process timing and safety is not compromised

Impact on LightingImpact on Lighting

PQ Issue:! Some HID metal halide

lamp/ballast systems are prone to blackouts due to voltage sags from the normal operation of large electric loads.

! Restart times may take as long as 10-15 minutes.

Susceptibility of High Susceptibility of High Pressure Sodium LightsPressure Sodium Lights

Non-Regulating Ballast

Auto-Regulating Ballast

Magnetic-Regulating Ballast

HPS Lamp Age (Hours of Use)

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New Lamp Old Lamp0 6,000 12,000 18,000 24,000

0

20

40

60

80

Sag Tolerance for HPS Ballasts vs. Lamp Operating Voltage

Voltage Sag Impact on ASDVoltage Sag Impact on ASD

Drive Trips on Undervoltage

InductionMotor

RectifierInverterInverter

dc Link

dc Bus Voltage

trip level

660V

420V

Undervoltage Trip PointUndervoltage Trip Point

!Typically set to 80-85% of nominal DC Bus voltage

!DC Bus voltage during sag depends on!Depth of voltage sag in each phase!Loading!Output frequency!DC capacitor value

With Ride-Through Device: Input Voltage, Motor Current, Motor Speed, and DC-Bus Voltage During a 50% Voltage Sag (100% Loading)

Evaluation of a DCEvaluation of a DC--BusBusRideRide--through Modulethrough Module

Additional ASD Voltage-SagTolerance from Ride Through

Device

ASD Voltage-Sag Tolerance without RideThrough Device

1 2 3 10 100

Time (Cycles at 60 Hz)

ASD Voltage Sag Tolerance for 100% Loading

100

90

80

70

60

50

40

30

20

10

0

CVT Output CVT Output (Sag to 50%(Sag to 50% VnomVnom))

MRD OutputMRD Output

Drive Programming ParameterDrive Programming Parameter

Solutions to drive problems:!Drives can be programmed to ‘restart’ after a

momentary voltage sag!Restart after motor coasts down to stop

(available in most of the drives)!Restart into a spinning motor

! Non-synchronous restart (motor slows down significantly)! Synchronous restart ( inverter picks up as soon as voltage

recovers - very promising technology; very few manufacturers provide this option)

Case Study ConclusionsCase Study Conclusions

! Site was experiencing over 300 thousand dollars per year in losses just on air handling processes

! Applying power conditioning on the ASD control transformers and in the PLC control cabinets was estimated to cost less than 75 thousand dollars complete

! Simple cost payback analysis approximately three months (300 K per year / 75K invested = 0.25 years)

“Sound” Power Quality “Sound” Power Quality AdviceAdvice

! Integrity of wiring and grounding is first!Provide nominal or “better” voltage!Don’t mix and match voltage ratings!Write PQ immune PLC programs!Understand programmable features!Maintain an upset log at every process line!Specify ride through and voltage regulation

for new and retrofit equipment

Voltage Support and Voltage Support and Regulation ConceptsRegulation Concepts

Ultracapacitor Energy Storage Ultracapacitor Energy Storage

! Ultracapacitors are receiving increased attention as a temporary power source for many applications.

! Traditionally considered for only low power applications, ultracapacitors are now being considered for use in higher-power applications.

! The shift in focus has been made possible through the asymmetrical ultracapacitor design.

What is a Standard Capacitor?What is a Standard Capacitor?

! Capacitance is directly related to the plate area and dielectric constant, but inversely related to the plate separation.

! Energy is stored in the dielectric through polarization.

What is an Ultracapacitor?What is an Ultracapacitor?

Energy is stored electrostatically at the electrode/electrolyte surface.

The large value of capacitance is due to the tremendous amount of surface area.

What is an Ultracapacitor?What is an Ultracapacitor?Ultracapacitors are configured into arrays using various-sized cells to fit the power and energy requirements for a specific application.

Features of UltracapacitorsFeatures of Ultracapacitors

Advantages:! Highest capacitance of any capacitor technology! Lowest cost per Farad! Reliable, long life! High cycle-life! Maintenance-free operation! Environmentally safe! High power density

What is an Asymmetrical Ultracapacitor?What is an Asymmetrical Ultracapacitor?

!The asymmetrical ultracapacitor is constructed using two different types of electrodes

Cp CmCp Cm

Cp = Cm = C

Ctotal = ½ C

Voltage of C = 0.8 V = V

Es = ½ CV2

= ½( ½ C)V2

= ¼ CV2

Cp>>Cm

Ctotal = 2C

Operation at ~1.6 V = 2 V

Ea = ½ (2C)(2V)2

= 4CV2

Symmetrical Asymmetrical

Therefore, Ea = 16 * Es!

Do They Work?Do They Work?

! In 1999 EPRI PEAC tested several asymmetrical ultracapacitors. The results confirmed the claims of the manufacturer

! Materials:! Activated Carbon, the main

ingredient in Odor Eaters!! Potassium Hydroxide

(KOH), the main ingredient in drain cleaner!

Voltage window: 16-8 V

Stored Energy: 1 MJ

Weight: 75 lbs (34 kg)

Advantages of UltracapacitorsAdvantages of Ultracapacitors

! State of charge is easily determined by measuring the terminal voltage

! Self-discharge rate is very low! Excellent low temperature performance and wide

range of operating temperature! Relatively inexpensive and environmentally

friendly materials (nickel, carbon, KOH)! Recharge efficiencies approaching 99 percent

Where Can Ultracapacitors Where Can Ultracapacitors Be Used?Be Used?

!High pulse power applications!Supplement to a battery!Direct replacement for lead-acid in some

short discharge applications!Regeneration applications!Opportunity charging applications!Hybrid vehicle applications

DemonstrationDemonstration

!EPRI PEAC has installed and demonstrated an ultracapacitor-based system.

!100 kW for 10 seconds (1 MJ).

Demonstration Fuel Cell System with Demonstration Fuel Cell System with Integrated UltracapacitorIntegrated Ultracapacitor

! 3 kW fuel cell system designed for fast response

DemonstrationDemonstration

! To demonstrate the incredible energy density of asymmetrical ultracapacitors, EPRI PEAC integrated the caps into a demonstration fork-truck.

Transportation ApplicationsTransportation Applications

Capacitor Powered Bus

Capacitor Powered Cart

Comparison of TechnologiesComparison of Technologies

Research and Application Research and Application OpportunitiesOpportunities

!Research:!Electrode Material!Electrolyte Material!Manufacturing Methods (Cost reduction)

!Applications:!Proof of concept for fast charging!Demonstrations of fork trucks and other

vehicles