Transcript Uninterruptible Power Supplies

UNINTERRUPTIBLE POWER SUPPLIES
JOHN LIGUORI
CONSULTING ENGINEER
MSEE, PE
PRESENTED TO THE IEEE LONG ISLAND CONSULTANT’S NETWORK
9/6/06
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UNINTERRUPTIBLE POWER SUPPLIES
• THIS PRESENTATION IS FOR INFORMATIONAL AND
EDUCATIONAL PURPOSES ONLY. IT DOES NOT CONTAIN ALL
INFORMATION REQUIRED, AND IS NOT INTENDED TO BE
USED FOR THE SPECIFICATION OR DESIGN OF
UNINTERRUPTIBLE POWER SUPPLIES (UPS) OR UPS
SYSTEMS.
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UNINTERRUPTIBLE POWER SUPPLIES
OUTLINE
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•
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•
•
•
•
INTRODUCTION
POWER DISTURBANCES
UNINTERRUPTIBLE POWER SUPPLIES
GENERAL DISCUSSION
SUMMARY
REFERENCES
QUESTIONS
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INTRODUCTION
• PURPOSE
• WHAT IS AN UNINTERRUPTIBLE POWER SUPPLY?
• WHY USE A UPS?
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PURPOSE
•
THE PURPOSE OF THIS PRESENTATION IS TO DISCUSS THE DIFFERENT
TYPES OF UNINTERRUPTIBLE POWER SUPPLIES AVAILABLE, WHAT THE UPS
PROTECTS AGAINST, THE COMPONENTS OF A UPS, AND ISSUES REGARDING
SELECTION AND SIZING.
•
THE DIFFERENT TYPES AND CAUSES OF POWER DISTURBANCES ARE
DISCUSSED, AS WELL AS WHAT THE POWER UTILITY, THE ORIGINAL
EQUIPMENT MANUFACTURER, AND YOU, CAN DO TO MINIMIZE THEIR
EFFECT.
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WHAT IS AN UNINTERRUPTIBLE POWER SUPPLY?
• AN UNINTERRUPTIBLE POWER SUPPLY (UPS) IS A DEVICE
THAT HAS AN ALTERNATE SOURCE OF ENERGY THAT CAN
PROVIDE POWER WHEN THE PRIMARY POWER SOURCE IS
TEMPORARILY DISABLED
• THE SWITCHOVER TIME MUST BE SMALL ENOUGH TO NOT
CAUSE A DISRUPTION IN THE OPERATION OF THE LOADS
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WHY USE A UPS?
• PROTECTS AGAINST MULTIPLE TYPES OF POWER
DISTURBANCES
• ONLY DEVICE THAT PROTECTS AGAINST AN OUTAGE
• OFFERS PROTECTION AGAINST
 EQUIPMENT NOT OPERATING PROPERLY
 COMPUTER AND EQUIPMENT DAMAGE
 DATA LOSS
 TIME AND EXPENSE TO RECOVER BACK TO WHERE
YOU WERE, IF EVEN POSSIBLE
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POWER DISTURBANCES
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•
•
•
•
•
•
CAUSES
TYPES
DURATION
RESULTING PROBLEMS
COMMENTS
WHAT THE POWER UTILITY CAN DO
WHAT THE ORIGINAL EQUIPMENT MANUFACTURER (OEM)
CAN DO
• WHAT YOU CAN DO
• PROTECTIVE DEVICES
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CAUSES OF POWER DISTURBANCES
• STORM ACTIVITY – LIGHTNING, WIND, ICE
• OBJECTS COMING IN CONTACT WITH POWER LINE AND
TRIPPING BREAKER – TREE BRANCHES, ANIMALS, OTHER
• UTILITY FAULT CLEARING
• CONSTRUCTION ACTIVITY
• ACCIDENTS – MOTOR VEHICLE, OTHER
• EQUIPMENT FAILURE
• OVERLOADING
• LOAD SWITCHING
• NON-LINEAR LOADS
• POOR GROUNDING
• ESD
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TYPES OF POWER DISTURBANCES
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•
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INTERRUPTION
SAG, UNDER VOLTAGE
SURGE, OVER VOLTAGE
VOLTAGE FLUCTUATION
FREQUENCY VARIATION
SPIKES / TRANSIENTS
 IMPULSIVE
 OSCILLATORY
• WAVEFORM DISTORTION





DC OFFSET
HARMONICS
INTERHARMONICS
NOTCHING
NOISE
• VOLTAGE IMBALANCE
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DURATION OF POWER DISTURBANCES
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INSTANTANEOUS
MOMENTARY
TEMPORARY
SUSTAINED
-
½ CYCLE (8 1/3 ms) OR LESS
½ CYCLE TO 3 SEC
3 SEC TO 1 MIN
GREATER THAN 1 MINUTE
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CLASSIFICATION OF PROBLEMS RESULTING FROM
POWER DISTURBANCES
• DISRUPTIVE
 EQUIPMENT DOES NOT OPERATE AS INTENDED
• DISSIPATIVE
 EQUIPMENT EXPERIENCES REPEATED STRESSES THAT LEAD TO
FAILURE LATER FOR NO APPARENT REASON
• DESTRUCTIVE
 EQUIPMENT FAILS AT THE INSTANT THE DISTURBANCE OCCURS
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PROBLEMS RESULTING FROM
POWER DISTURBANCES
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DATA ERRORS
DATA LOSS
BLOWN FUSES
TRIPPED BREAKERS
INTERFERENCE WITH CONTROL OF LOADS
OVERLOADED NEUTRAL CONDUCTORS
MOTORS





•
HEATING
SPEED VARIATION
STALLING
AUDIBLE NOISE
VIBRATION
TRANSFORMERS
 HEATING
 AUDIBLE NOISE
 VIBRATION
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POWER DISTURBANCES - COMMENTS
• NOT ONLY IS MODERN EQUIPMENT MORE SUSCEPTIBLE TO
POWER DISTURBANCES, BUT THE EQUIPMENT ITSELF
GENERATES MORE DISTURBANCES
• ALL LOADS, FROM LARGE POWERFULL MOTORS AND
INDUSTRIAL EQUIPMENT TO SMALL, SENSITIVE ELECTRONIC
COMPONENTS, ARE CONNECTED TO THE SAME POWER GRID
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WHAT THE POWER UTILITY CAN DO TO MINIMIZE
THE EFFECT OF POWER DISTURBANCES
• INSTALL STORM RESISTANT WIRING
• USE INFRA RED SCANNING TO DETECT WEAK SPOTS IN
POWER LINES
• INSTALL REMOTE CONTROLLED RADIO SWITCHES TO
RESTORE POWER QUICKLY
• CLEAR TREE LIMBS AWAY FROM POWER LINES
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WHAT THE OEM CAN DO TO MINIMIZE THE EFFECT
OF POWER DISTURBANCES
BUILD EQUIPMENT CONTAINING ONE OR MORE INTERNAL
PROTECTIVE DEVICES




SURGE PROTECTIVE DEVICES
LINE FILTERS
ISOLATION TRANSFORMER
BATTERY OR CAPACITOR BACK UP TO INCREASE RIDE THROUGH TIME
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WHAT YOU CAN DO TO MINIMIZE THE EFFECT OF
POWER DISTURBANCES
• BUY EQUIPMENT THAT HAS INTERNAL PROTECTIVE DEVICES
 FOR EXAMPLE, BATTERY BACK UP FOR ANY APPLIANCE THAT
CONTAINS A CLOCK
• USE ONE OR MORE EXTERNAL PROTECTIVE DEVICES





SURGE PROTECTORS
LINE FILTERS
ISOLATION TRANSFORMER
VOLTAGE REGULATING LINE CONDITIONER
UPS
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PROTECTIVE DEVICES OTHER THAN UPS
• SURGE PROTECTIVE DEVICES – SPD’S
PROTECTS AGAINST SPIKES OF LIMITED ENERGY
 METAL OXIDE VARISTORS – MOV
 DIODES
 GAS TUBES
 LCR FILTERS
 HYBRIDS
• LINE FILTERS
FILTERS OUT HARMONICS, TRANSIENTS AND NOISE
• ISOLATION TRANSFORMER
ELIMINATES DC OFFSET AND NOISE
• VOLTAGE REGULATING LINE CONDITIONER
AUTOMATICALLY ADJUSTS FOR UNDER AND OVER VOLTAGES
 CONSTANT VOLTAGE TRANSFORMER - CVT
 MOTORIZED VARIAC
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POWER DISTURBANCES
AND
PROTECTIVE DEVICES
POWER DISTURBANCE
SURGE
PROTECTOR
PROTECTIVE DEVICE OFFER PROTECTION?
LINE FILTER
ISOLATION
VOLTAGE
TRANSFORMER
REGULATING
LINE
CONDITIONER
INTERRUPTION
SAG, UNDER VOLTAGE
SURGE, OVER VOLTAGE
VOLTAGE FLUCTUATION
FREQUENCY VARIATION
SPIKES / TRANSIENTS
WAVEFORM DISTORTION
VOLTAGE IMBALANCE
YES
YES
YES
IMPULSIVE
OSCILLATORY
DC OFFSET
HARMONICS
INTERHARMONICS
NOTCHING
NOISE
YES
YES
YES
YES
YES
YES
YES
YES
YES
ON-LINE UPS
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
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UPS
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ARCHITECTURES
WAVEFORMS
INVERTER TECHNOLOGY
COMPONENTS
SWITCHOVER TIME
ADVANTAGES / DIS-ADVANTAGES
SIZING
BATTERY SAFETY
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UPS ARCHITECTURES
• LINE INTERACTIVE
• ON-LINE
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BLOCK DIAGRAM
LINE INTERACTIVE UPS
AUTOMATIC
SWITCH
AC SUPPLY
BATTERY
CHARGER
CRITICAL
LOAD
(AC)
INVERTER
DC TO AC
BATTERY
AC FAIL
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BLOCK DIAGRAM
ON-LINE UPS
AUTOMATIC
SWITCH
AC SUPPLY
CONVERTER
AC TO DC
INVERTER
DC TO AC
CRITICAL
LOAD
(AC)
BATTERY
INVERTER FAIL
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BLOCK DIAGRAM
LAPTOP COMPUTER POWER SUPPLY
CRITICAL
LOAD
AC SUPPLY
CONVERTER
AC TO DC
CONVERTER
DC TO DC
(DC)
BATTERY
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UPS WAVEFORMS
• TRUE SINEWAVE
• MODIFIED SINEWAVE
• SQUARE WAVE
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UPS WAVEFORMS
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VOLTAGE
TRUE SINEWAVE
MODIFIED SINEWAVE
SQUARE WAVE
0
0
4
8
12
16
20
TIME (ms)
-170
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INVERTER TECHNOLOGY FOR TRUE SINEWAVE
• PULSE WIDTH MODULATION - PWM
• LINEAR AMPLIFIER
• RESONANT INVERTER
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BLOCK DIAGRAM
PWM INVERTER
DC POWER
HIGH
FREQUENCY
GENERATOR
PULSE WIDTH
MODULATOR
BASE /
GATE
DRIVE
TRANSISTOR
BRIDGE
TRANSFORMER
FILTER
CRITICAL
LOAD
(AC)
REFERENCE
SINEWAVE
GENERATOR
COMPARISON
AMPLIFIER
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BLOCK DIAGRAM
LINEAR AMPLIFER INVERTER
DC POWER
SINEWAVE
OSCILLATOR
TRANSFORMER
CRITICAL
LOAD
(AC)
OSCILLATOR
AMPLIFIER
COMPARISON
AMPLIFIER
POWER
AMPLIFIER
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BLOCK DIAGRAM
RESONANT INVERTER
DC POWER
SQUARE
WAVE
GENERATOR
SWITCH
DRIVE
TRANSISTOR
SWITCHES
TRANSFORMER
LC RESONANT
TANK FILTER
CRITICAL
LOAD
(AC)
(OR FERRORESONANT)
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UPS COMPONENTS
• CONVERTER - AC TO DC
 SPD - PROTECTS AGAINST SPIKES AND TRANSIENTS
• BATTERY
 STORED ENERGY DEVICE - PROTECTS AGAINST INTERRUPTIONS
• INVERTER – DC TO AC
 WAVEFORM SYNTHESIS – PROTECTS AGAINST DC OFFSET AND
INTERHARMONICS
 FILTER – PROTECTS AGAINST HARMONICS, NOTCHING AND NOISE
 VOLTAGE REGULATOR – PROTECTS AGAINST SAGS, SURGES AND
FLUCTUATIONS
• MONITOR AND CONTROL HARDWARE / SOFTWARE
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SWITCHOVER TIME
• A TYPICAL SWITCHOVER TIME
2 – 4 ms
ONE QUARTER CYCLE OR LESS
FOR SOME EQUIPMENT THIS IS NOT TOLERABLE
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ADVANTAGES / DIS-ADVANTAGES OF THE
DIFFERENT UPS ARCHITECTURES
• LINE INTERACTIVE ADVANTAGES
 AC TO DC CONVERTER / BATTERY CHARGER DOES NOT HAVE TO
PROVIDE FULL LOAD POWER (POTENTIALLY CHEAPER)
 LESS STRESS ON DC TO AC INVERTER SINCE IT RUNS AT NO LOAD UNTIL
UPS SWITCHES TO BATTERY POWER (POTENTIALLY CHEAPER)
• ON-LINE ADVANTAGES
 ZERO SWITCHOVER TIME FROM MAIN LINE TO BATTERY POWER
 ALWAYS ISOLATED FROM POWER DISTURBANCES ON THE MAIN LINE
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SIZING THE UPS
• EQUIPMENT RATINGS FOR LOADS
 OBTAIN RATINGS FROM NAMEPLATE OR SPEC SHEET
 ENERGY USAGE MAY BE SPECIFIED IN VOLT AMPS (VA) OR WATTS (W)
AND IN VALUES THAT ARE EITHER MAXIMUM OR NOMINAL
 (VA) AND (W) ARE RELATED VIA THE POWER FACTOR
• TOTAL UPS LOAD MUST NOT EXCEED THE UPS VOLT AMP (VA)
RATING
• TOTAL UPS LOAD MUST NOT EXCEED THE UPS WATT (W)
RATING
• OVERSIZE / DERATE TO ADD LIFE
• RUNTIME CHARTS
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UPS SIZING – EXAMPLE SPREADSHEET
ITEM
1
2
3
4
5
6
7
8
9
10
11
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EQUIPMENT DESCRIPTION
MANUFACTURER
MODEL
VOLT
AMPS
MAX
POWER
(va)
(w)
NOTES
MAX
PC
MONITOR
EXTERNAL HARD DRIVE 1
EXTERNAL HARD DRIVE 2
AUDIO SYSTEM
PRINTER 1
PRINTER 2
CABLE MODEM
LAPTOP / DOCKING STATION
PHONE AND ANSWER MACHINE
LAMP
CLOCK
TOTAL
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BATTERY SAFETY
• MAINTENANCE
 INSPECT PERIODICALLY
 REPLACE AS NEEDED
• RISKS





ACID
ELECTRIC SHOCK
BURN
FLYING, MOLTEN METAL (EYES)
INJURIES RESULTING FROM CARRYING HEAVY BATTERY PACKS
• DISPOSAL
 DISPOSE OF PROPERLY
 RECYCLE WHENEVER POSSIBLE
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GENERAL DISCUSSION
• DOES A UPS OFFER COMPLETE PROTECTION?
• DO YOU THINK “POWER DISTURBANCES WON’T HAPPEN TO
YOU” ?
• MISCELLANEOUS
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DOES A UPS OFFER COMPLETE PROTECTION?
• SOME POWER DISTURBANCES MAY EXCEED THE HANDLING
CAPABILITY OF THE UPS
• UPS FAILURE
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DO YOU THINK “POWER DISTURBANCES WON’T
HAPPEN TO YOU” ?
• POWER DISTURBANCES OCCUR FREQUENTLY, THOUGH
MANY ARE SMALL AND WITHOUT CONSEQUENCE
• AN ON-LINE UPS CAN PROTECT AGAINST MORE SIGNIFICANT
POWER DISTURBANCES WHEN THEY DO OCCUR
• THE COST OF NOT HAVING A UPS CAN EASILY EXCEED THE
COST OF A UPS
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MISCELLANEOUS
• MANY RETAIL UPS FOR COMPUTER APPLICATIONS ARE LINE
INTERACTIVE
• MANUFACTURERS AND BUILDING CODES DO NOT ALLOW
EXTENSION CORDS OR SURGE SUPPRESSORS TO BE USED
WITH A UPS
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SUMMARY
THINGS TO CONSIDER WHEN SPECIFYING A UPS
• POWER QUALITY
 ARCHITECTURE - LINE INTERACTIVE OR ON-LINE
 WAVEFORM - SQUARE, MODIFIED SINE, TRUE SINE
 IMMUNITY TO DISTURBANCES OTHER THAN OUTAGE
•
•
•
•
RUN TIME WITH AN OUTAGE
RELIABILITY
AUDIBLE NOISE
MONITOR AND CONTROL HARDWARE / SOFTWARE
 LOCAL / REMOTE CONTROL
• INITIAL COST
• MAINTENANCE COST
• WARRANTY
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REFERENCES
• IEEE STANDARD 1100-2005
RECOMMENDED PRACTICE FOR POWERING AND GROUNDING SENSITIVE
ELECTRONIC EQUIPMENT
• IEEE STANDARD 1159-1995
RECOMMENDED PRACTICE FOR MONITORING ELECTRICAL POWER QUALITY
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QUESTIONS
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