Seminar by:
S.Murali krishnan5050910061-B Tech EEE,SRM University,Chennai
What is UPS?
UPS – Uninterruptible Power Supply is a
standby electrical Power source connected
between the Power Utility and the load.
• Modern Electronic gadgets and computer systems are highly sensitive to the power fluctuations• Disruption of power may lead to Data loss/ corruption/ malfunction etc.• Standby Power Sources - Generators• Starting the generator takes a few minutes. UPS is mainly used as a Power Backup for the above few minutes
• Modern Electronic gadgets and computer systems are highly sensitive to the power fluctuations• Disruption of power may lead to Data loss/ corruption/ malfunction etc.• Standby Power Sources - Generators• Starting the generator takes a few minutes. UPS is mainly used as a Power Backup for the above few minutes
• UPS maintains power instantaneously by switching to battery in the event of a power failure
or a dip (brown out)
• Used to condition the power supply by reducing
spikes and harmonics.
• Designed to correct a variety of power problems -
- Sags – Transient Under voltage
- Surge – Short duration high voltage
- Brownouts – Low voltage for long time
- Spikes – Brief but high energy bursts
- Line noise, frequency variation, switching
transient and Harmonic distortion
• UPS maintains power instantaneously by switching to battery in the event of a power failure
or a dip (brown out)
• Used to condition the power supply by reducing
spikes and harmonics.
• Designed to correct a variety of power problems -
- Sags – Transient Under voltage
- Surge – Short duration high voltage
- Brownouts – Low voltage for long time
- Spikes – Brief but high energy bursts
- Line noise, frequency variation, switching
transient and Harmonic distortion
Three types of UPS
1. Offline UPS
2. Line interactive UPS
3. Online UPS
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1. Offline UPS
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2. Line Interactive UPS
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3. Online UPS
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Online UPS
� Main components of UPS:
- Rectifier / Battery Charger
- Battery
- Inverter
� Main features for a Good UPS:
- Shortest changeover time < 4mS
- Sufficient battery backup time
- Quality output supply
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Online UPS
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Online UPS - Operation
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Online UPS
�Elements of UPS:
- Input
- Rectifier / Battery Charger
- DC System
- Inverter
- Output
- Static Bypass
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Online UPS
�Elements of UPS:
- Input
- Rectifier / Battery Charger
- DC System
- Inverter
- Output
- Static Bypass
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Online UPS - Input
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Online UPS - Input
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Online UPS - Input
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Online UPS - Input
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Online UPS
�Elements of UPS:
- Input
- Rectifier / Battery Charger
- DC System
- Inverter
- Output
- Static Bypass
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Online UPS -Rectifier
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Online UPS -Rectifier
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Online UPS -Rectifier
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Online UPS -Rectifier
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Online UPS -Rectifier
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Online UPS -Rectifier
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Online UPS -Rectifier
� Switching speeds and power ratings – SCR Vs IGBT
IGBT MOSFET
Thyristor IGCT
101 102 103 104
102
104
106
108
Th
yri
stor
IGBT
MOSFET
Pow
er (
VA
)
Switching Frequency (Hz)
IGCT
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Online UPS
�Elements of UPS:
- Input
- Rectifier / Battery Charger
- DC System
- Inverter
- Output
- Static Bypass
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Online UPS – DC System
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Online UPS – DC System
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Online UPS
�Elements of UPS:
- Input
- Rectifier / Battery Charger
- DC System
- Inverter
- Output
- Static Bypass
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Online UPS – Inverter
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Online UPS – Inverter
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Online UPS – Inverter
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Online UPS – Inverter
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Online UPS – Inverter
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Online UPS
�Elements of UPS:
- Input
- Rectifier / Battery Charger
- DC System
- Inverter
- Output
- Static Bypass
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Online UPS – Output
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Online UPS – Output
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Online UPS
�Elements of UPS:
- Input
- Rectifier / Battery Charger
- DC System
- Inverter
- Output
- Static Bypass
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Online UPS – Static Bypass
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Online UPS – Static Bypass
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Online UPS – Other points
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• Design Factors• Typical Circuit• Typical PCB• Faults• Do’s• Don’ts
Online UPS – Design Factors
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Online UPS – Typical Circuit
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Online UPS – Typical PCB
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Online UPS – Faults
� Overload Trip
� Battery Low trip
� Output OV/ UV
� Over Temperature
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Online UPS – Do’s
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Online UPS – Don’ts
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