Battery Back Up Systems vs. Cost of Power Outages
Battery Back Up Systems vs. Cost of Power Outages
Traffic UPS Systems Agenda
•
Benefits of Installing Traffic UPS System
• •
Power disturbances Case Studies Liability
Statistical data supporting the installations of the BBS UPS Topologies and Misconceptions
Power Outages • • • •
Storms High winds Lightning Ice on power lines
• • • •
Traffic accidents Construction work Digging Animals interfering with Hydro infrastructure
Common Power Disturbances Temporary or Long Term Outage –
Systems shut down
planned or accidental total loss of power
Momentary Interruption - very short planned
Equipment is tripped off
or accidental power loss Sag/Swell - Decrease (sag) or increase
Memory losses, data
(swell) in voltage
errors, equipment shut downs
Transient Notch - a sudden change in
Processing errors, data
voltage up to several thousand volts (also
loss, burned circuit
called impulse or spike)
boards
Noise or Harmonic Distortion - alteration of
Processing errors, data
the pure sine wave due to non-linear loads
loss, overheating
on the power supply
Effects of Power on Traffic Safety During power outages signalized intersections typically lose all functionality. Fact: Many motorists do not know who has the right of way when approaching a dark signal. Typically, two actions take place: motorists on the ‘main’ road assume they have the right of way and do not stop, or motorists will treat the dark signal as an all way stop. In 2003 alone, 1.4 million people suffered injuries as a result of intersection-related crashes. Safety risks escalate when traffic signals are not functioning.
Traffic Safety Fact: There is one intersection fatality every hour in the United States 2003 and 2004, 80 – 90% of dark signal accidents resulted in injuries compared to 33% for the average New York State accident Center for Infrastructure and Transportation Studies Technical Report No: 08‐01, June 1, 2008
Energy Crisis Fact: We face an energy crisis today where the slightest disruption in balance of supply and demand can lead to disaster. Fact: The oldest grids in Canada are nearly 150 years old. It’s prone to failure and it struggles to cope with the ever increasing demands of electricity. Fact: Over 400,000 kilometres of lines have been placed on an aging infrastructure, that cannot be easily powered down for maintenance. How do you repair a 500,000V line that cannot be switched off? Fact: Extreme weather & fires already cause 40% of all power outages in major cities
Energy Crisis of the Future Estimated that there will be a 30% increase in demand for electricity within the next decade alone! Outages of the future are predicted to last more than 24hrs. –CBC, Passionate Eye
Traffic Safety Fact: There is one intersection fatality every hour in the United States 2003 and 2004, 80 – 90% of dark signal accidents resulted in injuries compared to 33% for the average New York State accident Center for Infrastructure and Transportation Studies Technical Report No: 08‐01, June 1, 2008
Traffic Safety and Systems Flawless when good, clean, uninterrupted power is available. - Traffic moves safely and efficiently Or… Flawed with poor power -Traffic grinds to a halt. Commuters are left to deal with the disruption, crashes can occur, and safety can be compromised – and not forgetting the economic and environmental impact resulting from such delays.
Recent Report – March 2010 GRIDLOCK – Toronto in Dead Last “Study finds gridlock in GTA costs $5 billion/ year in lost productivity”
How to handle an outage
Do-Nothing Approach This is the norm – -Authorities that can take action may not know the power at an intersection is out -By the time the proper resources are notified to respond, the power many have been restored. TTC Bus crossing dark intersection during Jan’09 blackout
Police Since most power outages are unknown in advance the intersections that are controlled by police are often uncontrolled until the proper resources respond to the intersection.
Battery Backup Systems -To use a BBS efficiently, lights should be converted to LEDs -Provides full‐operation, flash‐operation, or a combination of both depending on the power requirements. -California Energy Commission in 2004 found that intersection with the BBS was used at least eight to ten times per year due to local power outages and have reduced traffic congestion, injury accidents and controller maintenance.
Liability – What is “Reasonably Foreseeable” ? In a 2000 press release it was noted that backup systems in California significantly improve the safety of an intersection, “according to Caltrans' research that began in 1993, traffic accidents have been reduced by 90% in certain high‐risk intersections due to battery back‐ups” *.
* Mitzi, Amon. California Traffic Light Programs Sets National Standards. Emerson Process Management. September 28, 2000.
Cost – Benefit Analysis At new intersections, the case for installing a battery backup system along with LED lights is only a fractional expense he overall cost.
The BBS has a favorable cost/benefit – particularly for important traffic corridors. An added benefit is that UPS also protect against poor power and surges that damage controllers and cause traffic lights to fail.
BBS Criteria Defined Consider traffic volume, frequency of injury accidents, proximity to a school zone, speed of approach traffic, and availability of pedestrian pre‐emption controls. Public Impact: What is the cost to human life when emergency vehicles fail to arrive quickly because they are entangled in traffic and unable to move? The direct and indirect costs that result when a system fails to operate far outweigh the initial cost of including a UPS.
BBS Criteria Defined
While the railroad crossing signal operation historically has battery backup when commercial power fails, the traffic signals typically have not.
Case Study: New York During the 2003 blackout, subways stopped, traffic lights went out, and police struggled to accommodate a mass exodus from New York City. However, during the summer of 2006 when a record-breaking heat wave caused major outages in many boroughs, there was calm instead of panic. Traffic lights continued to function normally in key sections of the city where Alpha Technologies backup power systems were installed.
Benefits of installing a Traffic UPS System • Safety – Prevent Accidents due to dark intersections • Keeps the traffic moving - Prevents Traffic Congestion due to power outages • Extends Life of Equipment – Regulated Power from the UPS prevents premature equipment failure • Lowers Cost – Eliminates the need for Police to direct traffic during a power outage
UPS Topologies and Misconceptions
Understanding Your Application How much transfer time is tolerated by mission-critical equipment?
The Switch-Mode Power Supply (SMPS)- SMPSs are the power supplies found in virtually all electronic equipment. They must have a “ride-through” time of 10 milliseconds or more to comply with international standards. Any electronic equipment that cannot sustain such a ride-through time is generally considered to be of inferior design or extremely rare — most likely an uncommon specialized application.
Features of the SMPS • Will accept wide variations in input voltage and frequency without degradation in performance to the equipment • They have built-in galvanic isolation between their AC input and DC outputs, eliminating the need for upstream common-mode (neutral-to-ground) isolation. • They can accept an appreciable amount of input voltage distortion without degradation in service life or reliability. • They have a built-in “ride-through” time to tolerate brief power interruptions.
SMPS International Standards Acceptable output limits of a UPS on the SMPS load: • For durations up to 1 millisecond, the UPS output voltage can go as high as 240V. • For durations up to 10 milliseconds, the UPS output voltage can be zero • For durations up to 100 milliseconds, less severe swings (either up or down) can be present — allowable duration depends on the severity of the disturbance. • For durations greater than 100 milliseconds (includes continuous operation), the UPS output voltage must remain between 96V and 132V.
UPS Topologies
Common UPS Topologies •
Standby
•
Line Interactive
•
Double Conversion (Online)
Standby UPS Simplified Block Diagram INPUT POWER Transfer Relay BATTERY CHARGER
INVERTER
BATTERY SYSTEM
• Normal operation from line • Switch over to UPS when power fails • Applications: home & small office business usage
OUTPUT POWER
Pro’s and Cons of a Standby UPS Pro’s
Con’s
• Low Cost
• No voltage regulation
• Small
• Minimal Load Protection
• Light Weight
• 4-6 ms transfer time • Square Wave
Line Interactive UPS Simplified Block Diagram
• Normal operation from line • Auto Voltage Regulation via Buck & Boost Mode • Batteries are not used in an undervoltage (brown-out) condition
Applications: Outdoor applications, home & business computer equipments
Pro’s and Cons of a Line Interactive UPS Pro’s
Con’s
• Low Cost/ TCO
•
Traffic UPS Systems Agenda
•
Benefits of Installing Traffic UPS System
• •
Power disturbances Case Studies Liability
Statistical data supporting the installations of the BBS UPS Topologies and Misconceptions
Power Outages • • • •
Storms High winds Lightning Ice on power lines
• • • •
Traffic accidents Construction work Digging Animals interfering with Hydro infrastructure
Common Power Disturbances Temporary or Long Term Outage –
Systems shut down
planned or accidental total loss of power
Momentary Interruption - very short planned
Equipment is tripped off
or accidental power loss Sag/Swell - Decrease (sag) or increase
Memory losses, data
(swell) in voltage
errors, equipment shut downs
Transient Notch - a sudden change in
Processing errors, data
voltage up to several thousand volts (also
loss, burned circuit
called impulse or spike)
boards
Noise or Harmonic Distortion - alteration of
Processing errors, data
the pure sine wave due to non-linear loads
loss, overheating
on the power supply
Effects of Power on Traffic Safety During power outages signalized intersections typically lose all functionality. Fact: Many motorists do not know who has the right of way when approaching a dark signal. Typically, two actions take place: motorists on the ‘main’ road assume they have the right of way and do not stop, or motorists will treat the dark signal as an all way stop. In 2003 alone, 1.4 million people suffered injuries as a result of intersection-related crashes. Safety risks escalate when traffic signals are not functioning.
Traffic Safety Fact: There is one intersection fatality every hour in the United States 2003 and 2004, 80 – 90% of dark signal accidents resulted in injuries compared to 33% for the average New York State accident Center for Infrastructure and Transportation Studies Technical Report No: 08‐01, June 1, 2008
Energy Crisis Fact: We face an energy crisis today where the slightest disruption in balance of supply and demand can lead to disaster. Fact: The oldest grids in Canada are nearly 150 years old. It’s prone to failure and it struggles to cope with the ever increasing demands of electricity. Fact: Over 400,000 kilometres of lines have been placed on an aging infrastructure, that cannot be easily powered down for maintenance. How do you repair a 500,000V line that cannot be switched off? Fact: Extreme weather & fires already cause 40% of all power outages in major cities
Energy Crisis of the Future Estimated that there will be a 30% increase in demand for electricity within the next decade alone! Outages of the future are predicted to last more than 24hrs. –CBC, Passionate Eye
Traffic Safety Fact: There is one intersection fatality every hour in the United States 2003 and 2004, 80 – 90% of dark signal accidents resulted in injuries compared to 33% for the average New York State accident Center for Infrastructure and Transportation Studies Technical Report No: 08‐01, June 1, 2008
Traffic Safety and Systems Flawless when good, clean, uninterrupted power is available. - Traffic moves safely and efficiently Or… Flawed with poor power -Traffic grinds to a halt. Commuters are left to deal with the disruption, crashes can occur, and safety can be compromised – and not forgetting the economic and environmental impact resulting from such delays.
Recent Report – March 2010 GRIDLOCK – Toronto in Dead Last “Study finds gridlock in GTA costs $5 billion/ year in lost productivity”
How to handle an outage
Do-Nothing Approach This is the norm – -Authorities that can take action may not know the power at an intersection is out -By the time the proper resources are notified to respond, the power many have been restored. TTC Bus crossing dark intersection during Jan’09 blackout
Police Since most power outages are unknown in advance the intersections that are controlled by police are often uncontrolled until the proper resources respond to the intersection.
Battery Backup Systems -To use a BBS efficiently, lights should be converted to LEDs -Provides full‐operation, flash‐operation, or a combination of both depending on the power requirements. -California Energy Commission in 2004 found that intersection with the BBS was used at least eight to ten times per year due to local power outages and have reduced traffic congestion, injury accidents and controller maintenance.
Liability – What is “Reasonably Foreseeable” ? In a 2000 press release it was noted that backup systems in California significantly improve the safety of an intersection, “according to Caltrans' research that began in 1993, traffic accidents have been reduced by 90% in certain high‐risk intersections due to battery back‐ups” *.
* Mitzi, Amon. California Traffic Light Programs Sets National Standards. Emerson Process Management. September 28, 2000.
Cost – Benefit Analysis At new intersections, the case for installing a battery backup system along with LED lights is only a fractional expense he overall cost.
The BBS has a favorable cost/benefit – particularly for important traffic corridors. An added benefit is that UPS also protect against poor power and surges that damage controllers and cause traffic lights to fail.
BBS Criteria Defined Consider traffic volume, frequency of injury accidents, proximity to a school zone, speed of approach traffic, and availability of pedestrian pre‐emption controls. Public Impact: What is the cost to human life when emergency vehicles fail to arrive quickly because they are entangled in traffic and unable to move? The direct and indirect costs that result when a system fails to operate far outweigh the initial cost of including a UPS.
BBS Criteria Defined
While the railroad crossing signal operation historically has battery backup when commercial power fails, the traffic signals typically have not.
Case Study: New York During the 2003 blackout, subways stopped, traffic lights went out, and police struggled to accommodate a mass exodus from New York City. However, during the summer of 2006 when a record-breaking heat wave caused major outages in many boroughs, there was calm instead of panic. Traffic lights continued to function normally in key sections of the city where Alpha Technologies backup power systems were installed.
Benefits of installing a Traffic UPS System • Safety – Prevent Accidents due to dark intersections • Keeps the traffic moving - Prevents Traffic Congestion due to power outages • Extends Life of Equipment – Regulated Power from the UPS prevents premature equipment failure • Lowers Cost – Eliminates the need for Police to direct traffic during a power outage
UPS Topologies and Misconceptions
Understanding Your Application How much transfer time is tolerated by mission-critical equipment?
The Switch-Mode Power Supply (SMPS)- SMPSs are the power supplies found in virtually all electronic equipment. They must have a “ride-through” time of 10 milliseconds or more to comply with international standards. Any electronic equipment that cannot sustain such a ride-through time is generally considered to be of inferior design or extremely rare — most likely an uncommon specialized application.
Features of the SMPS • Will accept wide variations in input voltage and frequency without degradation in performance to the equipment • They have built-in galvanic isolation between their AC input and DC outputs, eliminating the need for upstream common-mode (neutral-to-ground) isolation. • They can accept an appreciable amount of input voltage distortion without degradation in service life or reliability. • They have a built-in “ride-through” time to tolerate brief power interruptions.
SMPS International Standards Acceptable output limits of a UPS on the SMPS load: • For durations up to 1 millisecond, the UPS output voltage can go as high as 240V. • For durations up to 10 milliseconds, the UPS output voltage can be zero • For durations up to 100 milliseconds, less severe swings (either up or down) can be present — allowable duration depends on the severity of the disturbance. • For durations greater than 100 milliseconds (includes continuous operation), the UPS output voltage must remain between 96V and 132V.
UPS Topologies
Common UPS Topologies •
Standby
•
Line Interactive
•
Double Conversion (Online)
Standby UPS Simplified Block Diagram INPUT POWER Transfer Relay BATTERY CHARGER
INVERTER
BATTERY SYSTEM
• Normal operation from line • Switch over to UPS when power fails • Applications: home & small office business usage
OUTPUT POWER
Pro’s and Cons of a Standby UPS Pro’s
Con’s
• Low Cost
• No voltage regulation
• Small
• Minimal Load Protection
• Light Weight
• 4-6 ms transfer time • Square Wave
Line Interactive UPS Simplified Block Diagram
• Normal operation from line • Auto Voltage Regulation via Buck & Boost Mode • Batteries are not used in an undervoltage (brown-out) condition
Applications: Outdoor applications, home & business computer equipments
Pro’s and Cons of a Line Interactive UPS Pro’s
Con’s
• Low Cost/ TCO
•
