JONATHAN WHITE, PE FEBRUARY 16, 2016 WEAT FEBRUARY SEMINAR

Transcription

1 SCADA SYSTEMS: DESIGNING FOR RELIABILITY JONATHAN WHITE, PE FEBRUARY 16, 2016 WEAT FEBRUARY SEMINAR

2 A reliable SCADA system is achieved by 1 Providing redundancy at single points of failure 2 Enhancing reliability of communications systems 3 Mitigating adverse environmental conditions

3 Reliable SCADA systems require a comprehensive design approach Instrumentation Integrated Control Systems SCADA System

4 Reliable SCADA systems require a comprehensive design approach Process Design Electrical Design Programming Design Communications Systems Design HVAC Design SCADA System

5 A reliable SCADA system is achieved by 1 Providing redundancy at single points of failure 2 Enhancing reliability of communications systems 3 Mitigating adverse environmental conditions

6 Redundant methods can eliminate single points of failure Remote Telemetry Controller VFD Control Panel Wetwell

7 Redundant methods can eliminate single points of failure Remote Telemetry Controller VFD VFD Control Panel Wetwell

8 Redundant methods can eliminate single points of failure Remote Telemetry Controller VFD VFD Control Panel Wetwell

9 Redundant methods can eliminate single points of failure Remote Telemetry Controller VFD VFD Backup Relay Control Wetwell Control Panel

10 Redundant methods can eliminate single points of failure Remote Telemetry Cellular Controller VFD VFD Backup Relay Control Wetwell Control Panel

11 Redundant controllers protect against failures with a centralized approach Primary Server Primary PLC Main Control Building Remote I/O Panel Headworks Remote I/O Panel Aeration Basins Remote I/O Panel RAS/WAS

12 Redundant controllers protect against failures with a centralized approach Redundant crossload Primary Server Primary PLC Secondary PLC Sec. Server Main Control Building Remote I/O Panel Headworks Remote I/O Panel Aeration Basins Remote I/O Panel RAS/WAS

13 Distributed control approach eliminates single point of failure SCADA Server Main Control Building Standalone PLC Panel Headworks Standalone PLC Panel Standalone PLC Panel RAS/WAS Aeration Basins

14 Typical configurations only allow one path of communication Redundant crossload Primary PLC Secondary PLC Main Control Building RAS/WAS SPOF Remote I/O Panel Headworks Remote I/O Panel Aeration Basins Remote I/O Panel RAS/WAS

15 Ring configurations allow data to travel multiple ways Redundant crossload Primary PLC Secondary PLC Main Control Building Self Healing Ring Remote I/O Panel Headworks Remote I/O Panel Aeration Basins Remote I/O Panel RAS/WAS

16 Backup power is necessary to maintain system control UPS STANDBY GENERATOR 1 hour Critical time without power as generator kicks on 10 seconds 24 hours OUTAGE LENGTH

17 Redundant control executed at WWTP MGD WWTP Redundant PLCs & SCADA Servers 2 Local PLCs and RIO Panels 3 Ring Network Configuration

18 A robust SCADA system is achieved by 1 Providing redundancy at single points of failure 2 Enhancing reliability of communications systems 3 Mitigating adverse environmental conditions

19 Remote communication networks provide variable reliability MOST RELIABLE Dedicated fiber optic MOST CRITICAL SCADA OPERATIONS Radio telemetry Broadband LEAST RELIABLE Cellular LEAST CRITICAL SCADA OPERATIONS

20 Radio telemetry reliability depends on: Lightning Protection Fade Margin Data Rate Grounding is very important Surge protection at multiple levels Signal buffer at receiving end 20dB recommended Atmospheric conditions Keep coax lengths short Only transmit what is needed Slower rate = fewer errors

21 Remote communication provides secondary control REMOTE SECONDARY LOCAL PRIMARY RADIO SCADA Work station RADIO PLC

22 A robust SCADA system is achieved by 1 Providing redundancy at single points of failure 2 Enhancing reliability of communications systems 3 Mitigating adverse environmental conditions

23 Environmental conditions affect control reliability Reliability High Low Ideal Environmental Conditions Adverse

24 Proper cooling increases expected life Variable Frequency Drive Life Expectancy 90,000 Life in Hours 10 Years 60,000 5 Years 30, Temperature in F

25 Panel protection extends life expectancy Cost Type 1 Type 12 Type 3R Type 4X Type 7 Ingress of dirt Dirt, light splashing water Rain, snow, and sleet Rain, snow, sleet, hosedown water, corrosive agents Explosion Proof Hazardous locations

26 Comprehensive design approach creates SCADA system reliability 1 Provides redundancy at single points of failure 2 Enhances reliability of communications systems 3 Mitigates adverse environmental conditions

27 QUESTIONS? JONATHAN WHITE, PE WEAT FEBRUARY SEMINAR