1. Why AVRs fail to protectPower-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. 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! Because: Wrong equipment being used for wrong application! AVRs JUST CANNOT PROTECT POWER-SENSITIVE EQUIPMENT Period!

5. BackgroundWhy? • 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. BackgroundICT Equipment • Computers • Gateways • Routers • Switches • Hubs • Bridges • Adapters • VOIP Switches Brown-out Conditions • Sags • Surges • Spikes • Noise • Over-voltage • Under-voltage • EMI • RFI

7. BackgroundNature 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. BackgroundEnsuring PQR • Mains voltage stabilization • Electrical noise suppression • Harmonic filtrations • Electrical load isolation • Lightning protection • Mitigation of other brownout condition

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

13. SolutionIndigenous 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. SolutionTechnology • Innovative Series-PWM Topology • Switch-mode Technology • High-frequency PWM Technology • Intelligent high-frequency chopping of Series Transformer • Employs IGBT modules

15. SolutionPrinciple • 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. SolutionSalient 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. Solution

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