1. Why AVRs fail to protect Power-sensitive Equipment!
M. Navid Akram Ansari
Managing Director
Systek (Pvt.) Ltd.
February 2019

2. FLOW Writing on the Wall! Background Reasons Solution Features
Conclusion
Recommendation
Outlook

3. ‘All ICT equipment shall fail sooner than later, unless ...’
Writing on the Wall!
‘All ICT equipment shall fail sooner than later, unless ...’
(Anonymous)
Not because of Murphy’s Law:
‘Anything that can go wrong will go wrong’

4. Writing on the Wall! AVRs JUST CANNOT PROTECT
Because:
Wrong equipment being used for wrong application!
AVRs JUST CANNOT PROTECT
POWER-SENSITIVE EQUIPMENT
Period!

5. Background Why?
Most of the ICT equipment employ SPS (Switch-mode Power Supply)
The ICT equipment mostly remain ON causing SPS components to age quickly
Thus they become more prone to fault on brown-out conditions
The capacitor of input filter, diode of the rectifier or the switching device may fail

6. Background ICT Equipment
Computers
Hubs
Gateways
Bridges
Routers
Adapters
Switches
VOIP Switches
Brown-out Conditions
Sags
Over-voltage
Surges
Under-voltage
Spikes
EMI
Noise
RFI

7. Background Nature of ICT Equipment
Commonly narrow input voltage range
Prone to effects of brown-out conditions
Faulty SPS may pass RFI, spike or ripple to circuit
Power-sensitivity increases with increase in clock-speed
Require high-level of Power Quality & Reliability - PQR

8. Background Ensuring PQR
Mains voltage stabilization
Electrical noise suppression
Harmonic filtrations
Electrical load isolation
Lightning protection
Mitigation of other brownout condition

9. Reasons ICT Equipment get damaged because
Following are deployed to protect them:
Conventional Automatic Voltage Regulators (AVR)
Line Conditioners incorporating such AVR
These AVRs are based on one of the following:
Relay
Servo-motor
Both these types of AVRs are ineffective in protecting ICT equipment due to their inherent shortcomings

10. Reasons Drawbacks of Relay-based AVR
Sparking due to make and break of contacts
Early failure on frequent voltage fluctuations
Coarse voltage regulation due to finite tappings
Slower response on higher power ratings
Inability to mitigate brown-out conditions

11. Reasons Drawbacks of Servo-based AVR
Slow response to changes in input voltage
Pass on sudden sags or surges to load
Gradual slowing of response over time
Early failure in dusty environment
Extreme output voltage upon resumption of mains power
Inability to mitigate brown-out conditions

12. Solid-state Power-line Conditioner
Solution
Solid-state Power-line Conditioner
Incorporating:
Solid-state Electronic AVR
Galvanic Isolation
Additional Protection
Most important is the SOLID-STATE AVR

13. Solution Indigenous Solution
PWM SOLID-STATE
POWER-LINE CONDITIONER
40 kVA 3-f OUTDOOR UNIT
40 kVA 3-f INDOOR UNIT
10 kVA 1-f INDOOR UNIT

14. Solution Technology Innovative Series-PWM Topology
Switch-mode Technology
High-frequency PWM Technology
Intelligent high-frequency chopping of Series Transformer
Employs IGBT modules

15. Solution Principle
Series regulation transformer is used to control the output voltage
The output voltage is controlled through the secondary by stepping up or down the input voltage at the primary
The primary voltage is controlled by solid-state PWM switching of input voltage

16. Solution Salient Features
Extremely fast response to changes in input voltage
Effective mitigation of brown-out conditions
Averse to dust due to solid-state parts
Provides Galvanic Isolation from mains
Very high efficiency
High power-to-size ratio

17. Solid-state Power-line Conditioner
Solution
Parameter
Solid-state Power-line Conditioner
Conventional
Line Conditioner
Normal Stabilizer
Topology
Solid-state PWM
Servo-control
Servo / Relay-based
Response Time
20 ms
400 ms
~ 600ms
Accuracy
± 1.5%
± 2 - 5%
± 3 -10%
Input Range
V or
V (Ext. Range) V V
Surge Suppression
LC, VDR, RFI
VDR, RFI No
Efficiency
98%
95%
90%
Display
Interactive LCD
LCD
Input/Output Volt Meter
Hi/Low Voltage Protection
Yes
High Voltage Withstand
Up to 460V
Over Load Protection
Software & CB CB
ON Delay
Selectable
Remote Interface
Over -temperature Protection

18. Conclusion
Conventional AVRs (Stabilizers) cannot protect the power- sensitive ICT equipment
Line Conditioners incorporating such relay or servo-based AVR cannot protect ICT equipment either
Such Line Conditioners are NOT the Power-line Conditioners that are suitable for ICT equipment
The only solution are the SOLID-STATE Power-line Conditioners based on Solid-state AVRs

19. Recommendation
Deploy ONLY SOLID-STATE Power-line Conditioners to effective protect power-sensitive ICT equipment
Deploy SOLID-STATE Power-line Conditioners with wide input voltage range at sites with poor power conditions
Deploy SOLID-STATE Power-line Conditioners with Isolation Transformers at sites with poor earthing

20. Outlook Futuristic Features
Event logging
Input power analysis
3-f output even with 1 or 2-f outage
Internet and GPRS connectivity
Remote parameters monitoring
Remote operation control
AI for optimum performance

21. THANK YOU! PLEASE REMEMBER! All power-sensitive ICT equipment are
BOUND TO FAIL SOONER THAN LATER!
UNLESS:
Protected by SOLID-STATE
POWER-LINE CONDITIONER!
THANK YOU!