tuesday eaton medium voltage power factor correction...

© 2016 Eaton. All Rights Reserved.

Eaton Medium Voltage Power Factor Correction Solutions

Tom McCaughn Dave States

Sales Manager Senior Application Engineer

Andy Angrick

Power Quality Specialist

Tuesday


Power Factor Basics

3 © 2016 Eaton. All Rights Reserved. 3

Why consider PFC?

PF correction provides many benefits:

• Primary Benefit:

• Reduced electric utility bill if there is a penalty

• Other Benefits:

• Increased system capacity (generators, cables, transformers)

• Reduced losses (heat) in transformers and cables

• Improved voltage regulation

• Greening the power system

4 © 2016 Eaton. All Rights Reserved.

Power Factor Opportunities by Application

Source: IEEE

Std 141-1993

(IEEE Red Book)

Industry Percent Uncorrected PF

Brewery 76-80

Cement 80-85

Chemical 65-75

Coal Mine 65-80

Clothing 35-60

Electroplating 65-70

Foundry 75-80

Forge 70-80

Hospital 75-80

Machine manufacturing 60-65

Metal working 65-70

Office building 80-90

Oil-field pumping 40-60

Paint manufacturing 55-65

Plastic 75-80

Stamping 60-70

Steelworks 65-80

Textile 65-75


Design and Application Considerations


Low vs. Medium Voltage PFC

• Low Voltage PFC

• Typically connected at the 480 V level

• Improves kVA loading of LV substation

transformers (assuming inductive loads)

• Automatically switched units are very common

• Typical application is one per LV substation

• Generally more cost effective than installing multiple

fixed units

• Improves no-load to full-load voltage regulation

• Fixed units can also be used at electrical panels or

individual loads


Low vs. Medium Voltage PFC

• Medium Voltage PFC

• Typically connected at the service entrance or

customer’s MV substations

• Generally used in the following situations:

• Customer has MV loads (e.g., 4160 V induction motors)

• PFC is needed only for the purpose of reducing or

eliminating utility penalties


Primary Design Decisions for PFC

• Fixed versus Switched Operation

• Filtered/Anti-resonant versus Unfiltered

• Need to consider electrical system and load

characteristics

• Nominal Operating Voltage

• Total kVAR required

• Step Size (Switched/Automatic Units Only)

• Response Time (Automatic Units Only)


Detuned Filter Design Considerations


Tuning Selection Basics

• Harmonic Resonance

• The condition when the inductive impedance (X of

L) equals the capacitive impedance (=X of C, say

by adding PFC capacitors to an existing facility

where the transformer, motors generators and

cable mutual inductance acts as the inductor)

• Resonance can amplify existing harmonic voltages

(Parallel Resonance) and currents (Series

Resonance).


Resonance Basics


Harmonic Resonance


Series Resonance


Parallel Resonance


How to avoid resonance

• Change the capacitor size. Many times multiple

resonant points so not practical

• OR

• Fix the capacitors resonance point to an impossible

value = make it Anti resonant

• Impossible value = Frequencies that do not exist for

example 4.2 or 4.08 or 4.7 or 3.8 or 3.67 etc.

• Determined mostly by practicality of calculation of

inductor values (for ex. 4.2 = 5%, 4.08 = 6% etc.)

• Done by converting the capacitor into a tuned LC circuit

(add the “L”= inductor)


Selecting Proper Tuning

• Most facilities have harmonic spectrum with characteristic

harmonic order beginning with 5th harmonic.

• Selecting the tuning below 5th makes the most economical

sense.

• Too close to 5th = lower impedance to the 5th order and

higher current absorbed.

• Too close to 4th = can cause parallel resonance.

• Too far from 5th (3.8, 2.67 etc. much bigger inductor = too

much losses). But situations can exist to select these

tuning orders too.


4.7 vs 4.2 Tuning

• Both avoid resonance. Avoiding resonance is the key

criteria in selecting an anti resonant bank (detuned

filter).

• 4.7 tuned capacitor can absorb up to 50% more

harmonic currents into itself compared to 4.2 tuned

capacitor. (Size of transformer, impedance and size

and tuning of capacitor dependent).

• Harmonic currents can cause excessive heating (not

just I2R losses) but dielectric losses increase

exponentially with higher harmonic orders = higher

heat = lower life expectancy)


4.7 vs 4.2 Tuning

• In worst case scenario, purely due to harmonics (both

V and I), the design life expectancy of capacitors used

in a 4.7 tuned filter is 27,000 hours vs. 34,000 hours

in 4.2 detuned filter. Compare this to the design life of

100,000 hours at rated conditions.

• When there is no Power Quality study 4.2 tuning will

avoid resonance and protect the capacitor bank while

providing the needed kVAR’s


4.7 vs 4.2 Impedance Scan


PFC Detuned Filter Recommendations

• PFC banks react to “VAR” demand and so

cannot truly control how much harmonic is

absorbed which can sometimes lead to too

much harmonic current and failures.

• For PFC and resonance concerns begin by

recommending Anti Resonant “Detuned PFC”

• 4.2 detuned.

• Avoids resonance, provides PF correction.

• 50% less harmonic current than 4.7th resulting in

longer life


Considerations for Selecting PFC/ Anti-Resonant PFC

• Type of system (weak or strong – high or low

source impedance)

• Possibility of resonance

• Current Divider phenomenon

• Primary purpose of the capacitor bank

• Ratio of largest block of kVAR required to

capacitor step sizes

• Voltage rise / Lead PF penalties for fixed

stages/steps


MV PFC Minimum Specification Requirements

• Nominal Operating Voltage

• Operation Type (Fixed or Switched)

• Filtered/Anti-resonant or Unfiltered

• Please specify tuning point, such as 4.2H, if a

filtered unit is required

• Total kVAR required

• Step Size (Switched/Automatic Units Only)

• Response Time (If Standard 200 second

response time is not sufficient)


Eaton’s MV Metal-Enclosed Power Factor Correction Solutions


Eaton Power Factor Correction

• Eaton LV & MV PFC

solutions are

engineered and

manufactured in our

plant in the

Asheville, NC area.


MV Capacitor Banks

• AUTOVAR MV (2.4kV to 14.4kV

SWITCHED CAPACITOR)

Medium Voltage Metal Enclosed

Capacitor Bank.

Capacitor banks enclosed in a steel

enclosure for indoor or outdoor locations.

• UNIVAR-XV (FIXED CAPACITOR)

Capacitor cells with Terminal Box for

Indoor or Outdoor Installation.


Univar-XV Fixed Capacitors


Univar – XV Features

• NEMA 1/3R/12 Indoor/Outdoor

• Viewing Window – A viewing window has been added to

the front cover to allow routine inspection of fuse status

without opening the enclosure.

• Removable Front Cover – A removable front cover and

top cover.

• Typical Application: Full Voltage across the line start

induction motor, connected to motor terminals

• Fuses: Each phase is fused, 50kAIC rating.

• Capacitor: 3-phase internally delta connected with

internal discharge resistors.

• Voltage Range: 2,400V to 4,800V


Univar-XV Available Sizes

• The following sizes are available, in

increments of 25kVAR.

• 2400V 25kVAR – 825kVAR

• 4160V 25kVAR – 900kVAR

• 4800V 25kVAR – 900kVAR


Univar – XV Advantages

• Viewing window allows easy and safe

indication of fuse status

• Removable front and top panel allows easy

access to terminals for wiring – others are top

only

• More wiring space allows room for bends and

stress cones.


MV Autovar Engineered Metal Enclosed Banks

• Voltages from 2.3kV

to14.4kV

• 50 kVAR to 10,000 kVAR

• Heavy Duty NEMA 3R

Outdoor enclosure

• Custom Engineered and

Standard Designs available

• Fixed or Switched capacitor bank

• Automatic capacitor bank

• De-Tuned Anti-resonant Capacitor bank

with standard 4.2H tuning, other tunings

available (e.g., 4.4H, 4.6H, 4.7H, 6.7H)


Typical One-Line


MV PFC Sample Dimensional View


Shipping & Handling Information


Main-Tie-Main Bank Configuration


MV PFC Front View

Removable lifting eyes

Isolated Controls

Compartment

Capacitor compartment

Key interlocks

Main

Incoming

Section

Base

channel


MV Autovar Example: 13.2kV 1,200kVAR

13.2kV, 4.2H, (300 + 900 = 1200kVAR)

DETUNED FILTER CAPACITOR BANK


MV Autovar Example: 13.8kV 9000kVAR

13.8kV, 4.2H, (3000 + 3000 + 3000 = 9000kVAR)

DETUNED FILTER CAPACITOR BANK


MV Capacitor Bank Options

• Incoming section with NEMA 2 or 4 hole pads

• Main Disconnect

• Grounding Switch

• Surge arrestors

• Main fuses

• Control Power Transformer

• 1 to 10 stages

• Flexible stage sizes

• Non-Filtered or Detuned anti-resonant Filter

• Stages can be fixed or automatic or combination

• Thermostatically controlled space heater in each section

• Thermostatically controlled cooling fans in each section

• Eaton PowerXpert Communications Gateway

• And many more options


Capacitor Bank Control Features

• H-O-A Selector switch to manually force any stage

ON or OFF when not in automatic.

• Timers blocking re-closing of stage within 200

seconds. Allows time to discharge the cells.

• Digital Meter/Relay to display capacitor bank

current and phase current unbalance detection.

• Digital Power Factor Controller Eaton BLR-CM.

• 120V Circuit Breaker for control power

• Full Voltage LED Indicating Lights


15 kV MV PFC Interior View

Fuses

15KV

Vacuum

switches

Capacitors

Main

Incoming

Disconnect

Ground

Switch


5kV MV PFC Interior View Capacitor Fuses

Capacitor

Reactor

Arrestors Main Switch

Ground Switch

PT’s Main Fuses

Vacuum Contactor


Typical Control Panel Shatter Proof Glass Multifunction Digital Meter

Alarms & Control

Stage Counter

Future Stages

Kirk Key Interlock


Capacitor Fusing

Fault Current: Fuses rated

50KA, FULL VOLTAGE

Tank-Rupture: Maximum

clearing TCC curve must

coordinate with tank rupture

curve of the capacitor.


MV Autovar – Additional Advantages

• Shipping splits / Modular design

• Air filter replacement without entering the

enclosure

• Multifunction Relay

• Barriers between sections

• Floor pan in each section

• Anti-condensation heaters

• Control Power Transformer is standard


MV Autovar – Standard Designs

• Standard Designs are currently available for 4160 V

applications

• Available in the most commonly requested sizes

• Standard design units include the following features

• Main Switch

• Main Fuses

• Ground Switch

• Type CM controller with Modbus RTU RS-485 Com Port

• Integrated Meter/Relay

• Extreme Duty Capacitor Cells (Filtered units only)

• Optional Factory CSA Certification is available



• Unfiltered 4160 V, 60 Hz units



• Filtered 4160 V, 60 Hz units, 4.2H Detuned


EATON AUTOVAR MV

VS.

COMPETITION


MV Competitor Comparison – Part 1

EATON N C E A D G

Capacitor cells mounted vertically

with bushings on top so the oil does

not leak at the bushing weld.

Encapsulated Control Power

Transformer

Full Voltage LED Indicating Light

Isolated compartments for each

stage

Smaller Shipping Sections (90"W x

49"D) for easy handling and

installation. Sections shipped on

pallets for fork-lift handling.

Inrush reactors made with copper

windings and manufactured for

better cooling.


MV Competitor Comparison – Part 2 EATON N C E A D G

Bottom Steel Pan

Capacitor cells are HEAVY DUTY

55 Deg. C Rated, 15kA fault

handling and 125% Overvoltage

Capability

INFO NOT

PUBLISHED

INFO NOT

PUBLISHED

ISO-9001 Certification

Capacitor Fuses are Rated Full

SYSTEM VOLTAGE CLASS

INFO NOT

PUBLISHED

INFO NOT

PUBLISHED

INFO NOT

PUBLISHED

INFO NOT

PUBLISHED

INFO NOT

PUBLISHED

120V Control Power Surge

Protection

Incoming Section Designed for Both

TOP OR BOTTOM Entry as

Standard

INFO NOT

PUBLISHED

Multi-Ratio Current Transformers for

Capacitor Bank Current Monitoring

and Future Expansion


MV Competitor Comparison – Part 3

EATON N C E A D G

Only Front Access Clearance

Required

7.2KV Vacuum Contactors for 5kV

Capacitor bank

INFO NOT

PUBLISHED

INFO NOT

PUBLISHED

INFO NOT

PUBLISHED

INFO NOT

PUBLISHED

INFO NOT

PUBLISHED

Air Filters Removable without

opening enclosure door

11-Gauge or equivalent steel

thickness

INFO NOT

PUBLISHED

INFO NOT

PUBLISHED

INFO NOT

PUBLISHED

Redundant Cooling fans with

thermostat control offered as

standard


Other Eaton PFC Advantages

• Both LV & MV Eaton products built in Asheville, NC

• Eaton has a staff of 5 Application Engineers in the USA to

support pre and post sales questions

• Can be reached via an 800# or e-mail

• Eaton PFC customers are supported by over 300 Eaton field

service engineers in locations throughout North America

• Eaton PFC products are sold through local electrical distributors

who understand the area and provide local support

• Eaton has well qualified regional Manufactures Representatives

that can provide PFC application guidance and local support

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