1. Power Conditioners and Uninterruptible Power Supplies
Chapter 11
Power Conditioners and Uninterruptible Power Supplies
Becoming more of a concern as utility de-regulation proceeds
Copyright © 2003
by John Wiley & Sons, Inc.
Chapter 11 Power Conditioners
and UPS

2. Distortion in the Input Voltage
The voltage supplied by the utility may not be sinusoidal
Copyright © 2003
by John Wiley & Sons, Inc.
Chapter 11 Power Conditioners
and UPS

3. Typical Voltage Tolerance Envelope for Computer Systems
This has been superceded by a more recent standard
Copyright © 2003
by John Wiley & Sons, Inc.
Chapter 11 Power Conditioners
and UPS

4. Typical Range of Input Power Quality
Copyright © 2003
by John Wiley & Sons, Inc.
Chapter 11 Power Conditioners
and UPS

5. Electronic Tap Changers
Controls voltage magnitude by connecting the output to the appropriate transformer tap
Copyright © 2003
by John Wiley & Sons, Inc.
Chapter 11 Power Conditioners
and UPS

6. Uninterruptible Power Supplies (UPS)
Block diagram; energy storage is shown to be in batteries but other means are being investigated
Copyright © 2003
by John Wiley & Sons, Inc.
Chapter 11 Power Conditioners
and UPS

7. UPS: Possible Rectifier Arrangements
The input normally supplies power to the load as well as charges the battery bank
Copyright © 2003
by John Wiley & Sons, Inc.
Chapter 11 Power Conditioners
and UPS

8. UPS: Another Possible Rectifier Arrangement
Consists of a high-frequency isolation transformer
Copyright © 2003
by John Wiley & Sons, Inc.
Chapter 11 Power Conditioners
and UPS

9. UPS: Another Possible Input Arrangement
A separate small battery charger circuit
Copyright © 2003
by John Wiley & Sons, Inc.
Chapter 11 Power Conditioners
and UPS

10. Battery Charging Waveforms as Function of Time
Initially, a discharged battery is charged with a constant current
Copyright © 2003
by John Wiley & Sons, Inc.
Chapter 11 Power Conditioners
and UPS

11. UPS: Various Inverter Arrangements
Depends on applications, power ratings
Copyright © 2003
by John Wiley & Sons, Inc.
Chapter 11 Power Conditioners
and UPS

12. Chapter 11 Power Conditioners
UPS: Control
Typically the load is highly nonlinear and the voltage output of the UPS must be as close to the desired sinusoidal reference as possible
Copyright © 2003
by John Wiley & Sons, Inc.
Chapter 11 Power Conditioners
and UPS

13. UPS Supplying Several Loads
With higher power UPS supplying several loads, malfunction within one load should not disturb the other loads
Copyright © 2003
by John Wiley & Sons, Inc.
Chapter 11 Power Conditioners
and UPS

14. Another Possible UPS Arrangement
Functions of battery charging and the inverter are combined
Copyright © 2003
by John Wiley & Sons, Inc.
Chapter 11 Power Conditioners
and UPS

15. UPS: Using the Line Voltage as Backup
Needs static transfer switches
Copyright © 2003
by John Wiley & Sons, Inc.
Chapter 11 Power Conditioners
and UPS