1. Prof. Mohsin A Mulla
Assistant Professor, EE
SITCOE Yadrav
2. ◦ Effects of power quality
◦ Power Quality definitions revisited
◦ What is needed for PQ monitoring ?
◦ GE Multilin’s solution
PQMII
EPM9000 series
◦ Summary
Monitor and Analyze Power Disturbances, Disruptions & Harmonics
3. Power Quality issues cause business problems
such as:
◦ Lost productivity, idle people and
equipment
◦ Lost orders, good will, customers and
profits
◦ Lost transactions and orders not being
processed
◦ Revenue and accounting problems
◦ Customer and/or management
dissatisfaction
◦ Overtime required to make up for lost work
time
According to Electric Light and Power Magazine, 30 to 40 Percent
of All Business Downtime Is Related to Power Quality Problems.
4.
5. ◦ The sensitivity of today’s electronic equipment
makes it susceptible to power disturbances
◦ For some devices, a momentary disturbance can
cause
scrambled data
interrupted communications
a frozen mouse
system crashes and equipment failure
6. ◦ Berkeley Lab Study Estimates $80 Billion
Annual Cost of Power Interruptions …
Research News, Berkeley Lab, February 2,
2005
◦ $50 billon per year in the USA is lost as a
results of power quality breakdowns ….
Bank of America Report
◦ A manufacturing company lost more than $3
million one day last summer in Silicon Valley
when the “lights went out.” … New York
Times January 2000
◦ “A voltage sag in a paper mill can waste a
whole day of production - $250,000 loss” …
Business Week, June 17,, 1996
◦ Half of all computer problems and one-third
of all data loss can be traced back to the
power line … Contingency Planning
Research, LAN Times
7. ◦ Lost production
◦ Scrap
◦ Costs to restart
◦ Labor costs
◦ Equipment damage and
repair
◦ Other costs
• High Cost Facilities
o Semiconductor plants
o Pharmaceuticals
o Data centers
• Medium Cost Facilities
o Automotive manufacturing
o Glass plants
o Plastics & Chemicals
o Textiles
8. IEEE Categories
Std 1159-1995
Short Duration
Variations
Typical
Duration
Instantaneous Sag 0.5 – 30 cycles
Momentary Sag 30 cycles – 3
sec
Temporary Sag 3 sec – 1 min
9. IEEE Categories
Std 1159-1995
Short Duration
Variations
Typical
Duration
Instantaneous Sag 0.5 – 30 cycles
Momentary Sag 30 cycles – 3
sec.
Temporary Sag 3 sec – 1 min.
Instantaneous Swell 0.5 – 30 cycles
Momentary Swell 30 cycles – 3
sec.
Temporary Swell 3 sec – 1 min.
10. IEEE Categories
Std 1159-1995
Short Duration
Variations
Typical
Duration
Instantaneous Sag 0.5 – 30 cycles
Momentary Sag 30 cycles – 3
sec.
Temporary Sag 3 sec – 1 min.
Instantaneous Swell 0.5 – 30 cycles
Momentary Swell 30 cycles – 3
sec.
Temporary Swell 3 sec – 1 min.
Momentary Interruptions 0.5 – 30 cycles
Temporary Interruptions 30 cycles – 3
sec.
11. IEEE Categories
Std 1159-1995
Long Duration
Variations
Typical
Duration
Sustained interruptions > 1 min
Under voltages > 1 min
Over voltages > 1 min
12. IEEE Categories
Std 1159-1995
Long Duration
Variations
Typical
Duration
Sustained interruptions > 1 min
Under voltages > 1 min
Over voltages > 1 min
Voltage imbalance Steady state
Waveform Distortion
13. IEEE Categories
Std 1159-1995
Long Duration
Variations
Typical
Duration
Sustained interruptions > 1 min
Under voltages > 1 min
Over voltages > 1 min
Voltage imbalance Steady state
Waveform Distortion
DC offset Steady state
Harmonics Steady state
Inter harmonics Steady state
For Electric Utilities Control of Voltage and Prevention of Outages is Power
Quality
14. Utility Sources
◦ Lightning
◦ PF Correction
Equipment
◦ Faults
◦ Switching
Internal Sources
• Individual Loads –Lighting, Elevators, Coolers,
HVAC
• Uninterruptible Power Supplies
• Variable Frequency Drives
• Battery Chargers
• Large Motors During Startup
• Electronic Dimming Systems
• Lighting Ballasts (esp. Electronic)
• Arc Welders, and Other Arc Devices
• Medical Equipment, e.g. MRIs and X-Ray
Machines
• Office Equipment and Computers
• Wiring
15. Typical problems Disturbance Type Possible Causes
Overheated neutral
Intermittent lock-ups
Frequency deviations
Steady-state Shared neutrals
Improper or inadequate wiring
High source impedance
SCR/Rectifiers and notching
Harmonics
16. Typical problems Disturbance Type Possible Causes
Overheated neutral
Intermittent lock-ups
Frequency deviations
Steady-state Shared neutrals
Improper or inadequate wiring
High source impedance
SCR/Rectifiers and notching
Harmonics
Interruption
Garbled data
Random increase in harmonics levels
Utility faults
Inrush currents
Inadequate wiring
17. Typical problems Disturbance Type Possible Causes
Overheated neutral
Intermittent lock-ups
Frequency deviations
Steady-state Shared neutrals
Improper or inadequate wiring
High source impedance
SCR/Rectifiers and notching
Harmonics
Interruption
Garbled data
Random increase in harmonics levels
Utility faults
Inrush currents
Inadequate wiring
Intermittent lock-ups
Lights flicker
Garbled data
Sags/Swell Source voltage variations
Inrush/surge currents
Inadequate wiring
18. Typical problems Disturbance Type Possible Causes
Overheated neutral
Intermittent lock-ups
Frequency deviations
Steady-state Shared neutrals
Improper or inadequate wiring
High source impedance
SCR/Rectifiers and notching
Harmonics
Interruption
Garbled data
Random increase in harmonics levels
Utility faults
Inrush currents
Inadequate wiring
Intermittent lock-ups
Lights flicker
Garbled data
Sags/Swell Source voltage variations
Inrush/surge currents
Inadequate wiring
Component failure
Dielectric breakdown
Lock-ups
Garbled data
Wavy CRTs
Impulses
EMI/RFI
Lightning
Load switching
Capacitor switching
Static discharge
Hand-held radios
Loose wiring/arcing
19. Typical problems Disturbance Type Possible Causes
Overheated neutral
Intermittent lock-ups
Frequency deviations
Steady-state Shared neutrals
Improper or inadequate wiring
High source impedance
SCR/Rectifiers and notching
Harmonics
Interruption
Garbled data
Random increase in harmonics levels
Utility faults
Inrush currents
Inadequate wiring
Intermittent lock-ups
Lights flicker
Garbled data
Sags/Swell Source voltage variations
Inrush/surge currents
Inadequate wiring
Component failure
Dielectric breakdown
Lock-ups
Garbled data
Wavy CRTs
Impulses
EMI/RFI
Lightning
Load switching
Capacitor switching
Static discharge
Hand-held radios
Loose wiring/arcing
Overheated transformers and motors
Voltage and current distortions
Garbled data
Lock-ups
Harmonics Electronic loads
SCR/rectifier
20. Source: EPRI, 1994
Spikes, 7%
Sags, 56%
Outages,
6%
Swells,
31%
Sags (Dips)
Associated with system faults
Switching of heavy loads
Starting of large motors
Swells
System fault conditions
Switching on a large capacitor bank
Switching off a large load
21. Textile Industry
Plastics Industry
Glass Industry
Process Industry
Semiconductors
$1k $10k $100k $1M $10M
Losses per Voltage Sag Event
Source: EPRI “The Economics of Custom Power”, IEEE T&D Show 2003
24. Continuous PQ Monitoring Detects, Records, and Leads
to the Prevention of PQ Problems
• Power Quality monitoring provides a continuous
“Health Check” of a facility’s power system … for
example:
o Harmonic interaction between loads and
power conditioning equipment spotted
o High Inrush currents from equipment
startup detected
o Transients from load switching are seen
• It provides data to see, diagnose and avert
looming problems – “like squeaky brakes on a
car”
o Trends can be detected
o JIT equipment maintenance programs
can be established
• It acts like a “Black Box” on an airplane to tell
you what, when, and where a Power Quality
event occurred … to prevent it from reoccurring
25. PQ Monitors must detect and
record the 7 types of PQ
problems
◦ Transients
◦ Interruptions
◦ Sag/Under Voltage
◦ Swell/Over Voltage
◦ Waveform Distortion
◦ Voltage Fluctuations
◦ Frequency Variations
These include Flicker and
Compliance to ITI(CBEMA), IEEE
and ISO Standards
Plus they must …
• Be easy to use
• Be Suitable for continuously
monitoring indoors and outdoors
• Interface with standard PQ analysis
Software…PQDif format
• Be fast enough to capture high
speed events that produce
equipment problems
• Have enough storage to save the
waveforms you need
• Have PQ analysis tools that
produce usable, actionable
recommendations
26. Source: AGA Brazil
Meter: EPM9650
Period: Jan 2005 – Dec
2005
Continuous Monitoring of the Station for PQ Problems
33. GE Multilin provides the necessary tools for a successful PQ
disturbance analysis and allows users to take remedial actions
Accurate Measurement to
determine actual state
Examinations
Remedial actionsRemedy
Feels the pulse of the
power system network
Symptoms
High resolution recordings
for longer durations
GE Communicator
software
Diagnosis
34. If You Can’t Measure it You Can’t Manage
it
If You Can Measure it You Can Manage
it