Power Quality Overview - PDF Free Download

Power Quality Events Outage 1 Surge 2 Swell 3 Sag 4 Harmonics 5

What is Power Quality? The concept of powering and grounding sensitive electronic equipment in a manner that is suitable to the operation of that equipment. 1 What works for YOU and YOUR system??? 1 IEEE 1100-1992

How Much Downtime is Acceptable? Power Availability Equivalent Power Disruptions (yr) 99.9999999% ISPs, e-business, Communications, Electronics mfg. N+ Redundancy < 3 seconds 99.999% Pharma Processing Server Operating Systems Generators and Some UPS 5.3 minutes 99.9% 4 99.99% Hospitals, Airports, Universities Generator Only Residential Homes Typical Grid Power 0.88 hours 8.8 hours

Specification driven or problem resolution driven Specification Driven Problem Resolution Driven SPDs HMT UPS HCU EVR SRT PFC

Sources Normal (550 kva, 5% Impedance) Alternate (18% Impedance; Simulates a Generator) EPRI Sag Generator (200A) Surge Generator (7 kv) Natural Gas Generator (150 kw) Solar Power (44 kw) * High Current Test Set (30 ka)* Loads Residential, Commercial, Industrial, Data Center 320 Computer Power Supplies (160 kva, Harmonic Load) Resistive Load Bank (250 kw) Motor-Generator Sets Variable Frequency Drives 300 hp Induction Motor Electric Vehicle Supply Equipment 7

Purpose Teach Power system issues, especially power quality problems, are difficult to understand Demonstrate This is a full scale demonstration facility it s not a mock up! Using PQ meters and system software, you can see the results Seeing is believing! Demystify There is a considerable amount of mis-information and confusion in the marketplace regarding PQ and energy savings Help End users in selecting the most appropriate (economic and technical) solution R&D/Testing Evaluate and test equipment by Eaton and others 8

Technical vs. Economic Solutions Standard Transformer 75 kva Loaded with 100% Harmonics Harmonic Mitigating Transformer 176 105 Max Temp 176 ºF Max Temp 105 ºF 9

Solutions for EFFICIENCY

A Culture of SAFETY Understanding Arc Flash Hazards Remote Power Racking II ( RPR2 ) Remote racking with FlashGard MCC

Visitors Dr. Ralph Wyndrum IEEE President, USA you make Power Quality seem fun. Mike Holt (www.mikeholt.com) EPRI IEEE PES/IAS Chapters 55% Types of Visitors Eaton Employees Industrial/Commercial/ Residential End Users 20% 25% End Users Students, Consultants, Distributors, Partners 12 2013 Eaton. All Rights Reserved. 12

Students and Universities University of Pittsburgh IBEW Carnegie Mellon University Notre Dame Penn State University Ohio State University Point Park University Youngstown State University and others Senior Design Projects Harmonic Demo Surge Demo Load Bank Automation Data Center Build-out See and Learn Physical Experience In-depth Demo Training Power Quality Theory Electrical Distribution and more I learned more here in 2 hours than I did during an entire 16 week class! 13 EE Student (Junior, Undisclosed University)

The Power Systems Experience Center Full-scale power system Compare economic vs. technical solutions Demonstrate and test PQ, arc flash and energy solutions for: Residential Commercial Industrial Utility Data Center Green Technologies www.eaton.com/experience

Power Quality Concepts Harmonic Solutions Effective Grounding Voltage Variation Solutions Surge Solutions 15

Common Power Problems Interruption Sag Swell Voltage Variation Solutions Undervoltage Overvoltage Surge Solutions Harmonic Solutions Line Noise Switching Transients Harmonic Distortion 16

Surge Protection Harmonic Solutions Effective Grounding Voltage Variation Solutions Surge Solutions The two sources of surges/transient overvoltages that account for the majority of all events are switching and lightning 17

Symptoms of Voltage Transients Equipment damage Insulation breakdown on electrical conductors Premature aging of electrical and electronic equipment Process interruption Data loss and data transfer rate reduction 18

Equipment Damage Catastrophic damage to equipment can occur as a result of a high energy transient voltage event 19

Insulation Breakdown on Conductors Insulation rating on conductors is typically twice line voltage plus 1000V Transient voltages can be well in excess of 20kV insulation breakdown and motor winding failure can occur 20

Premature Aging and Failure Damage to trace on electronic printed circuit board Electronic Rust 21

Where Do Voltage Transients Come From? 22 20% External Lightning Capacitor switching Short circuits 80% Internal Load switching Short circuits Capacitor switching Imaging equipment VS Drives Arc welders Light dimmers

Surge - With Protection L 20,000 Volts 2000 A 20 Amps 10 Ω Load Some residual letthrough voltage. Manageable by load Ohms Law I=E/R I=200V/10Ω I=20 Amps G

Installation Lead Length Can Increase Let- Through Voltage by 15-25v Per Inch Additional Let-Through Voltage Using IEEE C1 (6000V, 3000A) Waveform (UL1449 Test Wave) Installation Criteria Order of Importance: 1) Lead Length - 75% reduction 2) Twisting Wires - 23% reduction 3) Larger Wire - minimal reduction

Surge Protection Problem Description: Power electronic devices have taken over our world at home, work and school Eaton Solution: Surge Protection ELECTRONICS Televisions, stereo systems, personal computers, video games, entertainment centers, DVD players, printer/fax/copier, satellite receivers, internet modems, telephone, answering machines, clock radios, MP3 players, various battery chargers The average college student has 18 electronic devices APPLIANCES Refrigerators, stoves, microwave ovens, countertop appliances, dishwashers, washer/dryer, electrical tools, treadmill, other exercise equipment INFRASTRUCTURE Air conditioner, heat pump, electric hot water tank, lighting control, garage door openers, lighting, security system, pool pump, hot tub controls $5-20,000 Typical $4-$15,000 Typical $7-25,000 Typical Costs do not include the substantial cost that may be required to hire electrician to repair/replace the infrastructure wiring 25

Grounding Example Phone Lines in PVC Conduit Phone Room 480 V 1200 A 208 V 800 A 208 V Metering 300 kva 208/120 V 500 kva 480 V 300 kva 208/120 V 26

Grounding Example Don t Use Isolated Ground Rods! NEC Violation IEEE Emerald Book Violation Isolated Ground Rod! Computer or Phone Equipmen t 208 V 800 A 300 kva 208/120 V 27

Solutions for Transient Voltages SPD Series Commercial/Industrial surge protection Integrated or side-mount CVX OEM and value line AEGIS Critical 120V and 230V loads Residential Complete Home Surge Protectors Surge Strips 28

Multi-Cycle Voltage Variations Sags are responsible for a majority of upsets and nuisance trips of sensitive electrical equipment Harmonic Solutions Effective Grounding Voltage Variation Solutions Surge Solutions 29

Symptoms of Voltage Sags Computer Rebooting or Locking-Up Drives Dropping Out Contactors Chatter or Open PLCs Locking-Up and Process Stoppage Corrupted data UV/HID Lamps Shutting Off Incandescent Lamps Flickering 30

Types of voltage variations Two components of a voltage variation Magnitude - can range from +/- 5% of nominal voltage to a complete outage Duration can last for cycles (milliseconds) or hours Cost and practicality of solution depends on the magnitude and duration of event 31

Which Solution Will Work? SAG SRT/DRT EVR UPS GEN 32

Voltage Sag Characteristics Retained Voltage Duration Number of Phases Affected 33

Where Do Sags Come From??? How can you prevent Let s have that??? a closer look. 34

Area of Vulnerability 40-70% X 20-40% 0-20% 70-90% 35

Drive Ride Through (DRT) Problem Description: Progressive Cavity Pumps ( screw pump ) 8 hours of downtime for short duration (<1 sec) events Boscan Oil Field (Maracaibo, Venezuela) Eaton Solution: Drive Ride Through (DRT) with Ultra Capacitor Energy Storage 36

Drive Ride Through (DRT) Field Results 95.5% Availability Increased to 99.2% Increased Production by 1440 Barrels per unit At $100/barrel Resulted in Revenue of $144,000 (USD) per unit in 4 months Total Revenue = $864,000 (USD) ROI < 1 month! 37

Sag Ride Through (SRT) Problem Description: UV treatment use in drinking water is increasing to reduce the homeland security risk and cost of chlorine treatment Medium Pressure UV Water Treatment Systems require 7-10 minutes to cool down and re-start after a sag event In order to comply with EPA requirements this can require alternate chemical treatment or rerunning the water through the system Eaton Solution: Sag Ride Through (SRT) 38

Sag Ride Through (SRT) Washington DC Drinking Water System Water Treatment Plant 12 Calgon Carbon 48 reactors installed treating up to 480 million gallons of water a day Patent pending solution using SRT solution with UV treatment units Reduces 95% of UV treatment light outages Ensures system exceeds EPA ultraviolet treatment standards UPS backup is a choice too Depends on the backup time needed Depends on the power quality at the site 39

3 (+1) Basic Types of UPS Standby Off Line Normal Operation Power Failure Event Powerware Series 3 The Series 3 (Stand-By) UPS delivers power protection from 3 of the most common power problems that threaten your equipment and data Interruption Sag Swell Line Interactive Buck/Boost Powerware Series 5 The Series 5 (Line-Interactive) UPS delivers power protection from 5 of the most common power problems that threaten your equipment and data Undervoltage Overvoltage Ferroresonant +1 Powerware Series Ferro The Series Ferro UPS delivers galvanic isolated power protection from 8 of the most common power problems that threaten equipment and data Harmonic distortion Line noise Switching transients On Line Double Conversion ( Powerware Series 9 The Series 9 (On-Line) UPS delivers power protection from all 9 of the most common power problems that threaten your equipment and data Frequency variation 41

Power conditioning options (non-ups) Eaton Solution Primary Benefit Rating Power-Sure 700 (EVR) Power-Sure 800 Power-Suppress 100 Power-Suppress T7 Sag Ride Through (SRT) Drive Ride Through (DRT) Harmonic Correction Unit (HCU) Voltage regulation 3-ph (10-300kVA) Sag/swell, noise, regulation Electrical noise (EMI/RFI) Electrical noise (EMI/RFI) Sag/swell, regulation Sags/interruptions for VFD s 1-ph (250VA-3.5VA) 3-ph (3.5kVA-25kVA) 1-ph (250VA-7.5kVA) 3-ph (15kVA-225kVA) 3-ph (75 kva-20mva) 3-ph (10HP-1000HP) Harmonics 3-ph (50A, 100A, 300A) Power Conditioning Website 42

Harmonic Distortion Harmonic problems are becoming more apparent because more equipment that produce harmonics are being applied to power systems Harmonic Solutions Effective Grounding Surge Solutions Voltage Variation Solutions 43

Harmonic Symptoms/Concerns Equipment Failure and Misoperation Notching (electronic control malfunctioning, regulator misoperation) Overheating/Failure (transformers, motors, cables/neutral) Nuisance Operation (fuses, breakers) Insulation deterioration Audible noise in electrical equipment Economic Considerations Oversizing (equipment is sized larger to accommodate harmonics) Losses/Inefficiencies/PF Penalties Inconsistent meter reading Harmonic Resonance with Power Factor Correction Capacitors 44

Introduction - Harmonics Utility is responsible for providing clean voltage Customer is responsible for not causing excessive current harmonics Utility can only be fairly judged if customer is within its current limits Harmonics cause voltage and current problems in power systems IEEE Std 519-1992 provides a basis for limiting harmonics Multiple methods exist for mitigating harmonics and one size does not fit all 45

Harmonics it s not that complicated. VE V = mc IIZ Z 2 d d h G U Misoperation Problems Heating Problems (Load Related) Source Impedance

Which came first? Voltage Distortion Current Distortion In this case the Egg! Current distortion causes Voltage distortion Voltage distortion is created by pulling distorted current through an impedance Amount of voltage distortion depends on: System impedance Amount of distorted current pulled through the impedance If either increases, V THD will increase

What s YOUR (Harmonic) Problem? Voltage Problem Current Problem Impedance Problem Solutions exist for every problem but you have to understand the problem first!

Sources of Harmonics General sources of harmonics Power electronic equipment (drives, rectifiers, computers, etc.) Arcing devices (welders, arc furnaces, florescent lights, etc.) Iron saturating devices (transformers) Rotating machines (generators) Most prevalent and growing harmonic sources Adjustable frequency drives (AFD) Switch-mode power supplies (computers) Fluorescent lightning 49

Internal vs. External Sources Some harmonic sources are internal VFDs, switch mode power supplies, etc. Other harmonic sources are external Customers sharing the same line Is the voltage distortion caused by you or your neighbor? Establish a baseline (your neighbor s load) Determine the incremental change (your load) 50

Harmonic Limits System Issues Actual measurements at 480 V main breaker - system with large variablefrequency drives Voltage distortion at no load is 4%! 51

Expected Harmonics Source Typical Harmonics* 6 Pulse Drive/Rectifier 5, 7, 11, 13, 17, 19 12 Pulse Drive/Rectifier 11, 13, 23, 25 18 Pulse Drive 17, 19, 35, 37 Switch-Mode Power Supply 3, 5, 7, 9, 11, 13 Fluorescent Lights 3, 5, 7, 9, 11, 13 Arcing Devices 2, 3, 4, 5, 7... Transformer Energization 2, 3, 4 * Generally, magnitude decreases as harmonic order increases H = NP+/-1 i.e. 6 Pulse Drive - 5, 7, 11, 13, 17, 19, 52

Harmonic Sources Continuous Current

But Remember Harmonics are not a problem unless they are a problem!

Harmonics and Heating Load 100% Harmonics Std Transformer Max Temp 176 F HMT Max Temp 105 F 55

Voltage Notching

Neutral Heating Oversize Equipment A B C N 10A at 180 Hz 10A at 60 Hz 10A at 180 Hz 10A at 60 Hz 10A at 180 Hz 10A at 60 Hz 0A at 60 Hz 30A at 180 Hz 57

3rd Harmonic Summation in Neutral 58

3rd Harmonic Summation in Neutral 59

Harmonics and Motor Heating X s X T M Linear Load (Motor) Draws Non-60Hz (Harmonic) Current 60 M Distorted Current Causes Distorted Voltage

Motor Heating and Vibrations Motor Heating Vibrations System Losses Like driving with one foot on the gas and one on the brake 61

Harmonics and Generators Generator Concerns Generator impedance is generally 3-4 times (16-18%) the equivalent source transformer (5-6%) Utility Souce Generator Source 4.4% Vthd 13% Vthd Same Load (all Drives) 62

Notching and Generators Generator Source may result in larger commutation notches and transients

Harmonics and Generators Utility Source 2.3% THD Generator Source 5.7% THD

Harmonics and Generators Example Generator Sync Failure Generator 1 (Loaded) Generator 2 (Unloaded)

Harmonics and Generators Example Generator Sync Failure Blue (top) = Generator 1 Bus Voltage Red (bottom) = Sync Check Voltage Generator #1 (Loaded) vs. Generator #2 (Unloaded) Blue (top) = 120 V Filtered Sync Check Input from Generator 1 Red (bottom) = 480 V Generator Bus Voltage Solution: Series-rated surge protector/ring-wave filter

Harmonics and Generators Generator Filter UPS Filter On/Off Utility Source Generator Source Harmonic Filter ON Harmonic Filter ON Harmonic Filter OFF

PF and Harmonics kva (and Amp) Reduction 125 kva 100 kw 75 kvar 103 kva 100 kw 25 kvar no PFC w/pfc 125 kva 103 kva 50 kvar 25 kvar 125 HP 50 kvar 100 kw 68

Somebody has to pay for capacity and losses Wasted Capacity (VAR s) Useful Work (Watts) Capacity (kva) 69

What is a VAR? Active power, also called real power, is measured in Watts or kw and performs Useful Work Electrical equipment like motors and transformers require reactive power create a Magnetic Field and allow work to be performed. This reactive power is called volt-amperes-reactive or VAR s Reactive power is measured in vars or kvars Capacitors also draw reactive power but this reactive power is 180 degrees opposite of motors. Total apparent power is called volt-amperes and is measured in VA or kva 70

Harmonic Resonance On November 7, 1940, at approximately 11:00 AM, the Tacoma Narrows suspension bridge collapsed due to wind-induced vibrations the bridge had only been open for traffic a few months. 71

Harmonic Resonance The Self Correcting Problem Blown Fuses Failed Capacitors Damaged Transformer Harmonics = Wind (Excites Resonance) 72

Harmonic Resonance h R kva kvar SC CAP X s 1500 kva 5.0% 480 V 200 HP Drive Source of Harmonics 500 HP 600 kvar Capacitor 73

Harmonic Resonance If a capacitor exists on the power system AND Harmonic producing loads are in use You MUST check for harmonic resonance (series and parallel)

Harmonic and PF Solutions Line Reactors and DC Chokes K-Rated/Drive Isolation Transformers Harmonic Mitigating Transformers/Phase Shifting Harmonically Hardened Capacitors Tuned and De-Tuned Filters Broadband Filters 18-Pulse Clean Power Drives Active Filters Active Rectifier UPS 75

PF Correction and Harmonic Filters Facilities requiring PF correction for utility penalties often use one of the following compensation methods: PF Capacitors (standard or switched) risk of harmonic resonance Harmonically Hardened capacitors like K-rated transformer Harmonic Filter Tuned to reduce overall harmonic distortion (typically 4.7 th tuning ) De-tuned to avoid resonance (typically 4.2 nd tuning ) Active Harmonic Filter (both harmonic compensation and PF correction) Capacitors Hardened Capacitors Cost Harmonic Filters Active Filters 76

Active Filter Harmonic Solutions Oversized Generator X s G X T 480 V Filter Low Distortion Electronic Ballast M HMT M Broadband Filter Active Rectifier or 18 Pulse M 12 Pulse + - HMT Active Rectifier, Filter or 12 Pulse UPS PF Corrected

Oversized Equipment Transformer Efficiency - 75 kva Example 0.99 Oversized Generator X s 0.985 0.98 0.975 0.97 G X T 480 V 0.965 0.96 0.955 15 25 35 50 75 100 % Load Resistive Load 100% Harmonic Load Oversized Transformer 2X Neutral

Drive and Rectifier Solutions Drive without line reactor Drive with line reactor Best cost/kva solution for drive harmonics

Current - % of Fundamental Effect of Drive Line Reactors 100% 80% Effect of Line Reactors 0.5% 3.0% 5.0% 60% 40% 20% 0% 1 3 5 7 9 11 13 15 17 19 Harmonic Order

How Does a Filter Work? Generator X s Harmonic Current Divides by Ratio of Harmonic Impedances G X T 6A 480 V 24A 12A 18A Filter Current Flows Here (On Phase Conductors) Total Harmonic Current Divides Here M M M M Filter 12A 12A 12A (5 th Harmonic)

Phase Shifting/Cancellation 12 Pulse, 18 Pulse or 24 Pulse Cancellation by Design #1 #2 12 Pulse Example

Harmonics and Cancellation Without Cancellation 24 Pulse Cancellation

Main HMT 5 th and 7 th Cancellation Say we have a three story building with a variety of loading. How much 5 th and 7 th cancellation can we expect? Normal Delta-Wye Normal Delta-Wye HMT-NON 0 Shift 5 Units 5 Units - 5 Units ZIG-ZAG CONNECTION 4 Units Normal Delta-Wye Normal Delta-Wye Normal Delta-Wye 4 Units 4 Units 3 Units Normal Delta-Wye HMT-NON 0 Shift Normal Delta-Wye Case 1 5+ 4+ 3= 12 Units - 3 Units ZIG-ZAG CONNECTION Case 2 5+ 4-3= 6 Units 3 Units Case 3-5+ 4 +3= 2 Units

18 Pulse Rectifier 18 Pulse Design Voltage Eaton Clean Power Current Drive CPX9000

Total Demand Distortion CPX 9000 Example HARMONIC 30 HZ 40 HZ 50 HZ 60 HZ THD (% of I 1 ) 26.7 % 14.1 % 9.1 % 5.9 % TDD (% of I L ) 3.6 % 4.1 % 4.5 % 4.8 % All Harmonics 8.2 9.2 10.1 10.8 RMS 31.9 65.8 110.7 183.1 1 (fundamental) 30.8 65.2 110.3 182.3 2 0.1 0.4 1.2 0.9 3 3.1 3.8 3.9 3.9 5 5.4 6.1 6.8 8.3 7 5.1 5.1 4.9 4.3 11 0.2 0.2 0.5 1.2 13 0.4 0.8 1.0 1.2 17 1.5 2.0 2.1 2.1 19 0.8 1.7 2.5 2.5 23 0.3 0.4 0.4 0.3 25 0.3 0.4 0.7 0.7 29 0.0 0.1 0.1 0.3 31 0.2 0.1 0.2 0.3 35 0.1 0.2 0.3 0.4 37 0.2 0.3 0.4 0.5 225 A Demand Load

Cost of Harmonic Correction Description Cost $/kva Cost p.u. Reactor 3 1 Capacitors (LV) 12 4 Filter (MV) 12 4 Filter (MV) Switched 15 5 K-Rated Transformer 20 7 Capacitors (LV) Switched 25 8 Filter (LV) 35 12 Filter (LV) Switched 45 15 Harmonic Mitigating Transformer 50 17 Blocking Filter (3rd's) 100 33 Broadband Filter (Drives) 100 33 Active Filter 150 50 Per unit costs compared to reactor pricing Note that prices are generalized for comparison only Some equipment must be fully rated for loads - others can be partially rated Capacitors are shown for reference only