Power Quality Solutions Overview

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Power Quality Solutions Overview
Presented by Leo Craig MIEE FinstSMM Riello UPS
Ltd www.riello-ups.co.uk
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Lost of Power Costs!!
Cost of Downtime for one hour loss of
supply Chemical and Pharmaceutical 1004k Financ
e/Business 800k Food and Beverage 22k Manufa
cturing 35K Transport 790k According to
Larry Owens of Silicon Valley Power, a blackout
costs Sun Microsystems "up to 1 million per
minute." source- www.nrel.gov
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Did You Know!
A typical computer system is subjected to more
than 125 potentially devastating power
disturbances each month. source - Business Week
Every hour of downtime for a typical mid-sized
network costs its owner 18,000.   source -
Business Week One-third of all data loss is
caused by power problems.  source - Business
Week Half of all computer problems are traced
to the power line. source - Business Week The
overall cost of these problems to businesses in
Europe is estimated to be in a range of 13-20.3
billion per year    source - CDA
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Power Quality

• GRID Distribution Codes
• Stipulates max / min values of voltage, frequency
  etc.
• BS EN 61000-4-7 (G5/4)
• Harmonics limits and regulations
• BS EN 50160
• Details typical disturbances found on the system.
• BS EN 61000-4-15
• Flicker measurement limits and methods
• BS EN 61000-4-30
• Class A B for monitoring compliancy

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Power Disturbances
Equipment Failure
CPU Damage
PSU damage
Hard Drive damage
Data corruption
Component stress
Component Damage
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Power is Essential in a Crisis

• EXTERNAL SOURCES
• Storms
• Fuel Shortages
• Over demand
• JCB Diggers
• Bird Strikes
• Grid Faults
• Dogs

October 23, 2006 SHOCKED Gary Davies saw his
dog erupt in flames after it peed on a live
power cable. Bailey the Staffordshire bull
terrier also cut power to 148 homes by cocking a
leg against a faulty pylon. Gary, 42, said
There was an almighty explosion and the whole
street lit up. I turned round and the dog was on
fire. Power was off for five hours in
Middlestone Moor, Co Durham. Last night Bailey
was recovering at home after being treated for
burns. Source The Sun
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Power is Essential in a Crisis

• INTERNAL SOURCE
• Factory equipment
• Office equipment
• Air conditioning and lift drive motors
• Nuisance Tripping (Harmonics PF)
• Maintenance
• Poor Cable Management

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Effects of Power Disturbances
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CBEMA Voltage Tolerance Curve
Computer Business Equipment Manufacturers
Association (CBEMA) curve
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Applying Protection-Building Overview
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Power Solutions
PowerProblem AutomaticVoltage Stabiliser (AVS) Motorised AutomaticVoltage Stabiliser (AVS) Electronic Power Conditioner CVT Ferro Resonate UPS (online) Dual Conversion DVRs Dynamic Voltage Restorers
Blackout / Power Failures ? ? ? ? ?
Sags /Brownouts ? ? ? ? ?
Surges / Overvoltages ? ? ? ? ?
Spikes / Transients ? ? ? ? ?
High Frequency Noise ? ? ? ? ?
Frequency Variation ? ? ? ? ?
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Specification Considerations

• Selecting a Solution
• Sizing the Equipment
• Site Considerations
• System Configuration
• Autonomy (Battery Back-up time)
• Communications

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Selecting a Solution
What do we need to know? The Disturbance The
Severity The Duration The Source The Effect
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Comparisons
Method Advantages Disadvantages Applications
Resistor Potentiometers Rheostats Inexpensive Easy to install Low efficiency Can be Fragile Bulky Limited use Manually adjusted Cannot regulate frequency Motor field control Variable loads
Transformer based AVSs Can provide high output voltage Robust Servo/motor-controlled Automated detection and control Good MTBF if maintained Require maintenance High power/weight ratio Slow to react Transformers are bulky and heavy Low efficiency Cannot regulate frequency Test engineering Fan Control Test instruments Welding equipment High voltage power supplies
Thyristor/Transformer based AVSs Can provide high output voltage Relatively Compact Automated detection and control Require little maintenance Good MTBF Average efficiency Robust Relatively good reaction time Transformers can be heavy Stepped output voltage Average efficiency Cannot regulate frequency Relatively wide output voltage tolerance Relatively good reaction time Electro-plating Furnaces Vacuum coating Materials handling Ozone generation Soft starters
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Comparisons
Method Advantages Disadvantages Applications
Ferro-resonate Transformer / Constant Voltage Transformer (CVT) Good reaction time Very Robust No Maintenance High MTBF No control circuits necessary Low efficiency Current limits (motor start) Very heavy Relatively wide output voltage tolerance Frequency sensitive Cannot regulate frequency PLC and control Harsh environments
UPS and UPS as AVSs No variation of output voltage regardless of input Full voltage and frequency regulation Requires little maintenance High MTBF and High MTTR Relatively small Very Robust High efficiency Frequency conversion Requires some maintenance especially if batteries used. Expensive to replace the batteries if necessary Batteries limit operational temperature Some systems maybe slightly more expensive IT Data applications Flicker Emergency Lighting Most environments
DVRs Voltage Regulation at LV, MV or HV High efficiency Environmentally friendly Only Regulates Voltage. Expensive. Semiconductor Fabrication Large process industries
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Sizing a Solution
Total load of equipment Load list Manufacturer
s rating plate will always be maximum worst case
load Stated Amps is often rated at 110Vac and
50 less at 230Vac Using the manufacturers
Watts (W) and Current (A) ratings may over- size
the solution by up to 50 or worse
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Sizing a UPS Case Study, DWP
From the published information the UPS was sized
with a load of 10.87kW. A 15kVA UPS that is
capable of supplying 12kW was selected. The
running load was estimated to be 6.5kWatts
(28Amps) for battery sizing. Once Installed,
the load was monitored and the maximum RMS
current drawn by the equipment above was 7.3 amps
(1.68 kWatts). Power drawn was 15 of the
manufacturers published data. This is an extreme
case but highlights the potential for
over-estimating.
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Sizing a Solution
Total load of equipment Load list Manufacturer
s rating plate will always be maximum worst case
load Stated Amps is often rated at 110Vac and
50 less at 230Vac Using the manufacturers
Watts (W) and Current (A) ratings may over- size
the solution by up to 50 or worse Measure
current RMS and Peak Remember to only
support the essential parts of the Load!
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Site Considerations

• Physical size.
• Delivering and positioning Will it go through
  the door?
• Physical weight.
• Can it go up the stairs?
• Will it fall through the floor?
• Location Access Installation Servicing -
  Security
• Floods, Chemicals and Gases.
• AC, Soil or water pipes overhead.
• Ventilation Removal of heat
• Regulations Fire regulations. EPO requirement?
• Site specific regulations Hospitals, military
  etc
• Interface with other equipment
• Generators

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Availability
Availability Term Downtime per Year
99.9999 Six nines 32 seconds
99.999 Five nines 5 minutes 35 seconds
99.99 Four nines 52 minutes 33 seconds
99.9 Three nines 8 hours 46 minutes
99 Two nines 87 hours 36 minutes
90 One nine 36 days 12 hours
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Configuration Options for Greater Resilience
Single UPS 99.99
Parallel UPS 99.99
Parallel Redundant UPS System 99.999
N2 Redundant UPS System 99.9999
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External Bypass Switch
Single UPS with External Bypass
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Autonomy

• Question - How long should the UPS support the
  load?
• Answer - Minimum autonomy as I have a generator!
• WRONG!
• The autonomy should be as long as it takes to
  carry out a controlled shutdown!
• Answer I want to keep going for 2, 4 or 8 hours
• WRONG!
• Temperature rise will be to great if theres for
  no air-conditioning 30-45 minutes.
• Also consider
• Type of Battery - Sealed lead Acid
• 5 Year or 10 Year design Life
• Batteries are the weakest link (2 strings or
  more)

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Communications

• Remote Indication LEDs, LCD, mimics
• Volt Free Contacts BMS
• Modem Remote interrogation by phone
• FCT (fixed cell terminals) for remote locations.
• 24/7 Monitoring

• Controlled Shutdown Monitoring Software
• RS 232 Direct connection to server/PC
• SNMP Presence on LAN WWW
• Keep critical servers running longer (load
  shedding)
• Real time monitoring
• 24/7 Monitoring - email alert, SMS, WAP

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Combined Therapies
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Key points

• Resilience Power Plan
• Keep it simple!
• Evaluate the Risks ()
• Calculate the Costs () Implementation and
  ownership

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And Finally
Any Questions ?
Thank you for listening