PQ Issues Identified in IT/Commercial Buildings and Mitigation By Rajen Mehta 21 March 2017 Pride Hotel, Pune

Highest reliability

100% Up-time

Design Optimization

Lower power bills

Better network quality

Lesser maintenance

Fully Compliant Systems

Efficient Utilities

Extended Equipment Life

1"

Availability is binary. POWER QUALITY is not.

2

– PQ"is"mul*+thronged"and"dynamic"

– Good"PQ"is"rela*vely"difficult"to"define"

– PQ"improvement"is"specific"to"the"systems"being"

reviewed"

– End"user"Vs."U*lity"Vs."OEM"responsibility?"

– Financial"and"life+cycle"benefits"of"good"PQ"may"

not"be"upfront"or"obvious"

–  Improving"PQ"is"an"ongoing"process"that"calls"for"

investments"of"*me,"effort"and"mone"

Savings in excess of

INR 7.5 Cr.

Quick Fact Check.

Have you faced an inexplicable DOWNTIME?

Facts that fast become norms to “live with”...

Has your facility attracted any non-compliance PQ PENALTIES ?

Is voltage quality a concern?

Have you faced sensitive equipment MALFUNCTIONS?

Some action on harmonics – on your agenda?

3"

The Hidden Menace.

Source: efficienergi survey 4"

"Voltage"

Varia*on"

"Rapid"

Voltages"

Sags"/"

Swells"

"

Transient"

V"+"

Unbalanc

e"

High"

Vthd"

I"+"

Unbalanc

e"

High"Ithd"

#"of"Loca*ons"Surveyed" 969" 969" 969" 969" 969" 892" 969" 892"

Health"Score"#"Loca*on"Wise" 10%" 27%" 6%" 15%" 1%" 14%" 25%" 41%"

0%"

25%"

50%"

200"

400"

600"

800"

1000"

#"Loca'o

ns"Surveyed"

Survey"on"Voltage"Quality""

"

Volta

ge"

Varia

*on"

"

Rapid"

Volta

ges"

Sags"

/"

Swell

s"

"

Trans

ient"

V"+"

Unba

lance"

High"

Vthd"

I"+"

Unba

lance"

High"

Ithd"

#"of"Facili*es"Studied" 66" 66" 66" 66" 66" 70" 66" 70"

Health"Score"#"Facility"Wise" 44%" 67%" 14%" 48%" 8%" 12%" 55%" 87%"

0%"

25%"

50%"

75%"

100%"

64"65"66"67"68"69"70"71"

#"Indu

strie

s"

Survey"on"Voltage"Quality""

The Hidden Menace (Cont..)

Source: efficienergi survey

Ground"Poten*als/

Leakage"Poor"Loop"Impedance"

#"of"Facili*es"Studied" 29" 49"

Health"Score"#"Facility"

Wise"48%" 64%"

0%"

25%"

50%"

75%"

10"15"20"25"30"35"40"45"50"55"

#"Indu

strie

s"

Survey"on"Earthing"Quality""

Ground"Poten*als/

Leakage"Poor"Loop"Impedance"

#"of"Loca*ons"Surveyed" 1348" 5744"

Health"Score"#"Loca*on"

Wise"6%" 13%"

0%"

25%"

0"1000"2000"3000"4000"5000"6000"7000"

#"Loca'o

ns"Surveyed"

Survey"on"Earthing"Quality"

5"

The Hidden Menace (Cont..)

Source: efficienergi survey

"RCD"Test"

Failed""PI"Test"Failed" "CI"Test"Failed"

"Coordina*on"

Failed"

Discrimina*on"

Failed"

"

Thermography"

#"of"Facili*es"Studied" 6" 20" 30" 13" 11" 76"

Health"Score"#"Facility"Wise" 33%" 35%" 27%" 92%" 73%" 88%"

0%"

25%"

50%"

75%"

100%"

0"

20"

40"

60"

80"

#"Indu

strie

s"

Survey"on"Electrical"Infra"Health"

6"

Energy wastage"

energyberg Most 'state-of-the-art' energy and power network infrastructure do NOT deliver their real worth.

Malfunctioning

Energy spikes Penalties

Downtime

Data loss"

Sub-optimal designs"

Bad Power Quality"

Undesired Harmonics"

Fire Hazards"

Overheating"

Earthing problems"

Power conditioning problems"

non-compliance"

What we see

What’s the root cause?

Compromised Safety

8"

Improving Network Quality = Managing Collective Responsibility!

• PQ"compliant"Equipment,"PQ"Standards"

• Network"Quality"Monitoring,"Performance"obliga*ons"on"OEMs"Projects"and"Consultants"

• Awareness"building"regards"PQ"contractual"obliga*onss"U*li*es"

• Pre/Post"Installa*on/Commissioning"checks,"Sensi*za*on"of"all"project"stakeholders"EPC"and"Contractors"

• Electrical"Network"Quality"Data"Monitoring"frameworks"

End"Use"and"Maintenance"

• Publish"PQ"Compliance/Standards,"Align"to"meet"PQ"goals"for"the"electrical"network"OEMs"

9"

Impact of Poor PQ on Electrical Network Life Cycle in Commercial/IT

Design Build Commission Pilot Production Steady State

Sustainability goals unmet

Retrofit

Faster ageing

Constant

firefighting for uptime

Ad-hoc

solutions

Over-rating

Improper power conditioning

Rework

High installation cost

Functional Failures

Failed compliance/safety

PQ risks across the network lifecycle

10"

Why Network Quality – Few Thoughts –  Compliance requirements by Grid owners, end users, OEMs –

harmonics, voltage quality, ground potentials

–  IST (Integrated System Testing) / Pre-Post Commissioning Tests

–  Contractual obligations

–  Performance monitoring & verification of installed systems /equipment

–  For Justifying CAPEX proposals

–  Root Cause & Failure Analysis

–  Benchmarking Studies – Mainly Grid Level

–  “Fixing the blame Audit” (expecting Pre-conceived Outcomes)

11"

PQ = Lot’s of Myths PQ myths that need corrections

–  PQ ≠ (just) PF correction

–  Harmonics ≠ Always harmful

–  Oversized System ≠ Better PQ

–  UPS/SVR/Harmonic Filter ≠ “The” solution for PQ

–  PV/Wind Generation ≠ No PQ issues

–  Additional earthing stns ≠ protection of sensitive equipment …and many more

12"

Poor PQ – Caused by Utilities or Our Facility?

No-Load PQ Study Low High

Criticality

Solution Usage

14"

Cap Bank, Motor failures, Neutral Overload, Overheating, Tripping etc.

PF Improvement/Harmonics Mitigation Study

The"recommended"limits"in"this"clause"apply"only"at"the"point"of"common"coupling"and"

should"not"be"applied"to"either"individual"pieces"of"equipment"or"at"loca*ons"within"a"

user’s"facility.""

Low High

Criticality

Solution Usage

At"the"PCC,"system"owners"or"operators"

should"limit"line+to+neutral"voltage"

harmonics"as"follows:""

"

!""Daily"99th"percen*le"very"short"*me"(3"s)"

values"should"be"less"than"1.5"*mes"the"

values"given"in"Table"1.""

"

!""Weekly"95th"percen*le"short"*me"(10"

min)"values"should"be"less"than"the"values"

given"in"Table"1.""

15"

IEEE 519 – 2014

PF Improvement/Harmonics Mitigation Study Low High

Criticality

Solution Usage

!""Daily"99th"percen*le"very"short"*me"(3"s)"

harmonic"currents"should"be"less"than"2.0"

*mes"the"values"given"in"Table"2.""

"

!""Weekly"99th"percen*le"short"*me"(10"

min)"harmonic"currents"should"be"less"than"

1.5"*mes"the"values"given"in"Table"2.""

"

!""Weekly"95th"percen*le"short"*me"(10"

min)"harmonic"currents"should"be"less"than"

the"values"given"in"Table"2.""

16"

IEEE 519 – 2014 Contd

All values should be in percent of the maximum demand current, IL. This current value is established at the PCC and should be taken as the sum of the currents corresponding to the maximum demand during each of the twelve previous months divided by 12.

Cap Bank, Motor failures, Neutral Overload, Overheating, Tripping etc.

Harmonic Pollution due to drives A Chemical plant

Fully Automated Manufacturing with major loads comprising drives, automation, warehousing cranes, induction motors.

CASE

STU

DY

17"

Symptoms

•  High no of motor failures •  Motor locking or process stoppages •  Humming noise from capacitor banks •  7% detuned PF compensation

equipment remained ON when plant ran frequently on DG set

•  7-9% voltage distortion due to non-linear load when DG ON

•  Premature derating of the capacitor banks

Recommendations

•  Upgrade the Detuned PF compensation equipment to a Hybrid Harmonic Filter (Active + Passive) due to the variable source impedance as well as very high distortions near load end due to majority of non-linear load

•  Distribute load such that a single generator would not be loaded with more than 25-30% of non-linear load

•  Consult Drive manufacturer to modify control such that generator feedback could be incorporated & filters switched OFF

Unattributed Equipment Malfunctions and Downtime

Advanced PQ Analysis/Audit

Voltage Sags

Low High

Criticality

Solution Usage

18"

DG Start-up Failures/Issues

Advanced PQ Analysis/Audit Low High

Criticality

Solution Usage

19"

Symptoms

•  Critical rectifier power modules started failing at a rate of 1 module every 2-3 days

•  RCA conducted in the following areas •  Frequency Disturbances •  Amplitude Disturbances: Time > 1 cycle •  Transients & Periodic (Slow voltages/over voltages/

voltage dropouts) •  Periodic Voltage Fluctuations & flickers •  EMI/RFI/DC–fields •  Amplitude Disturbances: Time < 1 cycle •  Transients (Fast voltage changes/voltage spikes &

notches) •  Periodic (Harmonics) •  Three Phase Symmetry

Recommendations

•  External •  Capacitor Switching in stages •  Evaluate possibility to route the client supply through a

more robust feeder

•  Internal •  Mitigation equipment to arrest transients at the

facility mains and near the sub-mains and equipment sub DBs.

•  Decoupling inductance, k-30 rated

•  Mitigating coupling channel effect by: •  Tuning PF compensation equipment •  Installing a low impedance earth derivative to provide

the stable neutral under transient state of the network at the transformer secondary

Failing Rectifier Power Modules Regional hub of a multinational into communications capabilities deliverance Equipment consist of high end tele-communication processing equipment, such as DC rectifiers, Routers, Gateway Switches, UPS, SMPS, Server Racks, etc.

CASE

STU

DY

20"

Voltage/high Frequency Transient

Mitigation using SPD Low High

Criticality

Solution Usage

Date Time Duration (mSec) Signal Type Peak

TRANSFORMER MAINS 20/02/10 04:50:23 199 V31 Swell 585.3 20/02/10 04:50:23 71 V12 Swell 571.3 20/02/10 04:50:23 24 V23 Swell 560.3 21/02/10 08:46:26 8 V31 Swell 454.1 22/02/10 06:26:36 8 V31 Swell 452.7 23/02/10 04:48:20 16 V12 Swell 498.0 23/02/10 04:48:20 8 V23 Swell 542.3 24/02/10 05:33:43 291 V23 Swell 692.8 24/02/10 05:33:43 333 V12 Swell 542.2 25/02/10 05:35:11 8 V23 Swell 464.8 28/02/10 08:32:41 8 V1N Swell 911.1 01/03/10 08:37:00 12 V2N Swell 747.2 02/03/10 07:10:41 28 V3N Swell 956.5 03/03/10 06:56:22 8 V2N Swell 801.1 05/03/10 08:34:57 8 V31 Swell 522.1 06/03/10 06:05:47 8 V12 Dip 179.6 06/03/10 06:05:47 8 V23 Swell 501.8 06/03/10 06:05:47 8 V31 Swell 516.5 06/03/10 07:36:34 8 V12 Swell 462.3 07/03/10 07:31:49 8 V12 Swell 531.8 07/03/10 08:16:41 16 V23 Dip 270.4 07/03/10 08:16:41 16 V31 Dip 154.1 08/03/10 06:23:27 24 V23 Swell 510.6

Date Time

27-02-10 08.30 28-02-10 08.32 01-03-10 08.35 02-03-10 07.10 03-03-10 07.00 04-03-10 07.05

05/3/2010 08.35 06/3/2010 07.38 07/3/2010 07.32 08/3/2010 06.22 09/3/2010 07.21

HT Capacitor Switching Times The cells highlighted in yellow match with the times of HT Capacitor switching as shown in the adjacent table

21"

3� Symmetry Study

Sr.No. Location/FeederBreaker2Rating2(A)

NEV$(volt)PE$$$$$$$

(mA)BE$$$$$$$

(mA)NE$$$$$$(mA)

Sigma$Current$(mA)

1 1st$floor$Main$incomer 125.00 A A A2 1st$Floor$15A$socket$for$BERA$M/C 15.00 7.4V A A A 311.003 1st$Floor$5A$socket$ 5.00 8.0V A A A 200.004 1st$floor$Raw$power$AC$DB 40.00 A A A A A5 1st$floor$UPS$DB 40.00 A A A A6 1st$floor$15A$socket$for$Sonography$M/C 15.00 A A A A7 1st$floor$15A$socket$for$Sonography$M/C 15.00 A A A A8 1st$floor$Raw$power$15A$socket 15.00 A A A A9 2nd$floor$Raw$power$AC$DB 40.00 A A A A10 2nd$floor$Main$Incomer 125.00 A A A 3.611 2nd$floor$UPS A 1.4*v A 2.29 188.00 15012 Ground$floor$EB$supply$Main$I/C 160.00 A A NA 1 NA13 GF$Main$Incomer 100.00 A A 1 0.714 Raw$AC$DB 63.00 A A 5.50 1 0.315 Lighting$&$Power$DB 63.00 A A 2.30 1 0.516 Ground$floor$meter$room$socket A 1.25*v A A 1 116 Earth$PitA01 A A A A 1 2517 Earth$PitA02 A A A A 1 26818 Earth$PitA03 A A A A 1 019 Earth$PitA04 A A A A 1 NA

THREE$PHASE$SYMMETRY$TEST

TEST2RESULT

Multiple N-G loops, mixing of critical and raw power earthing, Neutral Swap over

Malfunctions in Sensitive/ Critical Loads Server Racks, Hospital Equipment

Low High

Criticality

Solution Usage

23"

Malfunctions in Sensitive/ Critical Loads Server Racks, Hospital Equipment

Low High

Criticality

Solution Usage

Poor Earthing Systems

Earth Loop Impedance Study & Earth Resistance Study 24"

System Performance and Reliability – As Designed

Pre-Commissioning – IST (Integrated System Testing)

GeneratorEngine Alternator

Fuel tank

UPS PDU RPP

RPP

CRAC

BTDealing / Communication

Other tenants

Tr

UV

Grid power

ATS

Cage Servers

MHCB servers�

� � �

��

��

500KVA x 3

Oscilloscope

�

��

��

��

��

��

UPS circuitEssential

��

��

��

��

��

��

None UPS , Generator circuit

Airconditioning & othersNone essential

Typical Voltage Waveforms

Single Line Diagram for PQ Study measurements

Low High

Criticality

Solution Usage 29"

Spurious Tripping, Excessive Voltage Drops, Arc Flash Hazards

Electrical Network Modelling Low High

Criticality

Solution Usage 31"

Electro Magnetic Compatibility (EMC) & EMI/RF Studies

Divation(from(ref(value

Remark

µT KV/Mtr µT KV/Mtr%(of(ref(µT

%(of(ref(kV/mtr µT KV/Mtr µT KV/Mtr Pass/Fail

20#Meter 5 10 0.1 0.0 +99% 0.1 0 Pass40#Meter 5 10 0.1 0.1 +99% Pass60#Meter 5 10 0.1 0.1 +99% Pass

140#Meter#(220/22KV#Transformer#at#MSETCL#Switch#yard)

4.2 0.5 0.4 0.1 0.11 0.02 Fail

160#Meter 5 10 0.3 0.6 +95% 0.1 0.2 0.06 0.4 Pass180#Meter 5 10 0.1 0.3 +98% 0.1 0.2 0.06 0.2 Pass200#Meter 5 10 0.5 0.5 +90% 0.2 0.2 Pass

220#Meter#(220/22KV#Transformer#at#MSETCL#Switch#yard)

1.1 0.5 0.1 0.1 Fail

240#Meter 5 10 0.2 0.4 +96% 0.1 0.1 Pass260#Meter 5 10 0.1 0.3 +99% 0.1 0.1 Pass280#Meter 5 10 0.1 0.3 +97% 0.1 0.1 Pass

300#Meter#(over#head#220KV#Double#circuit#line)(22KV#switch#yard#start)

0.3 1.4 0.2 1.4 Fail

320#Meter 5 10 0.3 0.6 +95% 0.2 1.6 Pass340#Meter 5 10 0.1 0.3 +97% 0.1 0.3 Pass360#Meter 5 10 0.1 0.3 +98% 0.1 0.2 Pass

0'(Meter(Boundary(of(MSETCL(&(Gigaplex

10'(Meter(from(

Boundary(wall(in(side(of(

20'(Meter(from(Boundarywall(in(side(of(Gigaplex(plotDistance(in(meter

Reference(Values

Low High

Criticality

Solution Usage

32"

Interference between Power and Voice/Data network

Mitigation Summary

34"

Source:""

EPRI"

1st Level Mitigation

•  Isolation xfmrs on Output side (UPS/DB/Floor level)

•  SPDs – B20C3 •  Reduction in failures –

but not elimination

2nd Level Mitigation

•  UPS power earthing separated, earth junction boxes installed, BE & CPE separated,

•  Improved loop impedance and six monthly thermal scans

•  Design standardization for greenfield projects

Periodic PQ Audits (3 years) BPO with over 1 Lakh Sq. Ft. Area

Server failures, Rebooting, Flash memory wipeout, Desktop MCB/DB trippings, Desktop HDD failures, SMPS failures, UPS / ATS tripping

Annual PQ audits spread over 3-4 years

Some Challenges Transparent Info sharing between IT user and Facilities Management

CASE

STU

DY

36"

Remember! Reliability Improvement through Power Quality is

–  Not a one time effort

–  Spread through the entire life cycle : Design to Steady State

Operation

–  To be incorporated through careful modeling and component

selection at design

–  To be done periodically during normal operation

–  With IIot can be monitored and analyzed on a 24/7 basis

–  Will yield significant direct and indirect benefits and high ROI

with the correct application

37"

Connect with us

Efficienergi Consulting Pvt. Ltd. 1303, B Wing, O2 Twin Towers, Minerva Industrial Estate, Mulund (W), Mumbai, 400080.

+91 22 2591 22 44 +91 22 2592 22 11

rajen@efficienergi.com info@efficienergi.com

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38"