A Journey into the U.S. Electric Power Grid
Tom Ferguson, P.E.Adjunct InstructorDept. of Electrical EngineeringUniversity of Minnesota, Duluth
Presentation to EE 1001September 18, 2014
© 2014 Tom Ferguson
A Journey Into the Grid
• High School: Voltage Regulation Issue• High School: Grounding Lesson• College: Theory Behind it All!• NSP: Grid Impacts from Thermal Storage• MP: Fields from Power Lines on Comm• MP: Power System Control• MP: Everything High Voltage• MP: Global Exposure, Major Changes in Industry• Retired: Sharing What I Learned; Still Exploring
© 2014 Tom Ferguson
Basic Power System
Generation Transmission Distribution “Behind the Meter”
© 2014 Tom Ferguson
In Ninth Grade . . .
Learned about electronics through amateur radio . . . but my knowledge of power systems was limited to this:
You plug stuffinto outlets.
© 2014 Tom Ferguson
Then Came the Big Radio Amplifier – and Dim Lights
Voltage Drop DueTo Resistance
240 V AC 210 V AC
© 2014 Tom Ferguson
Later in High School, I Learned About Grounds (the hard way)
120 Vac
Neutral
Ground
Chassis of
Radio Receiver
Chassis Of
Teletype Decoder
© 2014 Tom Ferguson
College Filled in Many Missing Blanks . . .. . . on Power Generation Technologies
© 2014 Tom Ferguson
Concentrations Driven by Questions
Power-Related Multi-course Concentrations
•Electromagnetic Fields (7!)
•All EE Power Courses
•Heat Transfer
•Nuclear Reactor Design
Includes• Hydro• Biomass• Wind• Solid Waste• Geothermal• Solar PV• Solar Thermal
Source: U.S. Energy Information Administration, Electric Power Monthly (June 2013). Percentages based on Table 1.1 for 2012 Calender Year.http://www.eia.gov/electricity/monthly/index.cfm?src=Electricity-f2 Updated 9/2013. Percentages on an ENERGY basis, not capacity.
Coal 37%
Natural Gas 30%
Nuclear 19%
Renewables 12%
2012
© 2014 Tom Ferguson
College Introduced the Immense Scale of the Power Grid
“The Grid” = Generators (about 18,000) + HV Transmission Network
© 2014 Tom Ferguson
Moving Power Across Long Distances
• High Voltage Transmission Lines – Connect generators with loads– Transmit energy at near speed of light– High voltage reduces current flow (P=V x I)
– Reduced current reduces losses (Ploss=I2R)
© 2014 Tom Ferguson
College Started to Answer Some Very Big Questions
• How is energy converted to electricity?• How does power flow down parallel paths?• What happens when a 500,000 volt line shorts?• What happens when a large generator suddenly quits
generating power?• How are nuclear, coal, wind and solar different?• How are generators controlled to minimize cost?• What’s happening: electrons or electromagnetic waves?• Often, just knowing the questions helps you get a job!
© 2014 Tom Ferguson
First Real Job: Telecommunications Engineer
• Voice, data, video system design– Within a utility and with neighbors
– Voice communications
– Remote monitoring and control
– Private systems for security, reliability
• Microwave, fiber optics, radio• Digital and analog, narrow and wide bandwidth• Design engineering and performance analysis• Power systems require robust communications, but
– Power systems also AFFECT telecomm systems
© 2014 Tom Ferguson
A Few Years Later: A Large Power System Control Project
• Managed a project team– HW and SW engineers, users– Accountants, schedulers
• An “Energy Management System”– Controls generators, substations, gates, valves, etc– Interfaces humans with control technology– Utilizes software to simplify, predict, suggest– Constantly matches generated power with loads
© 2014 Tom Ferguson
Energy Management System
EMS
Substations Neighboring Utilities
Stream Flows, Pond Levels, Weather
Stations, Lightning Data
System Operators
Alarm and Historical
Data Systems Power System
Study Engineers
Power System Simulators
and Training Energy ControlCenter
© 2014 Tom Ferguson
A Few Jobs Later: Management
• High voltage transmission system– Planning, design, operations, maintenance, construction
– Disciplines: electrical, mechanical, civil, structural
– Technical, plus: budgets, regulations, laws, policy
• Industry committees – More engineers, now from around the world
– Engineers as managers always go back to their roots
• Customer satisfaction
© 2014 Tom Ferguson
The Grid Powers Society
• Human behavior repeats itself daily– Morning routine: lights, hot water, electronics
– Stores open: lights, heating/cooling
– Industry starts: pumps, motors, arc furnaces
• The grid must respond to these loads– generators must be ready and reliable
– generators must be controllable to match load
– transmission/distribution lines must be intact (operating)
• It had better work well, or society struggles• Y2K exposed society’s worry
© 2014 Tom Ferguson
You Learn That Not All Power Systems are the Same
Types of generation vary across U.S. according to– availability of fossil fuels– availability of renewable energy sources– water availability– environmental limitations– state policies on renewables and nonrenewable
generation
Some require very specialized engineering skills
© 2014 Tom Ferguson
You Learn That Not All Power Systems are the Same . . .
Smaller Utility•Telecomm Engineer
•Substation Engineer
Large Utility•Microwave Engineer•Fiber Optics Engineer•Radio Systems Engineer
•Grounding Engineer•Transformer Engineer•Bushing Engineer•Protection Engineer•Substation Envir. Engineer•Rodent Control Specialist (!)
© 2014 Tom Ferguson
. . . And That Change is Constant
Before 1996•Utilities:
– Chose generation
– Set prices
– Operated “closed” systems
•Customers:– Had no choice of supplier
– Put up with indifference
•Renewable Generation– No subsidies, no interest
1996 to the Present•Utilities:
– Forced to open up trans. system
– Must compete with other suppliers
– Must allow oversight of operations
•Customers:– Can buy energy from anyone
– Pay “reasonable” delivery rates
– Are treated much better
•Renewable Generation – Mandated; subsidized to compete
– Is a threat to grid reliability
© 2014 Tom Ferguson
Challenges with Wind Generation • Adds no inertia to grid (no energy storage)• Relatively poor low-voltage behavior• Limited contribution to peak load capability• Not dispatchable• Negative correlation with loads• But the technology is fascinating!
When loads are greatest during the mid-day, wind generation is usually lowest.Conversely, wind is highest when least needed (night). Plots depict a day in California.
© 2014 Tom Ferguson
The U.S./Canadian Grid is Also Fascinating!
• Largest, most complex machine humankind has created• Speed of light energy movement• Three Synchronized Regions
– Eastern (east of Rockies)
– Western
– Texas
• All generators in
each region are
synchronized (60 Hz)
© 2014 Tom Ferguson
The Journey Never Ends
• Your Journey Continues with the Next Two Speakers– Scott Norr, UMD EE Department
– Andrew Remus, Minnesota Power
• The electric power industry is unique!– Societal value leads to great personal satisfaction
– Ethical behavior of people is second-to-none
– Huge opportunities: technology complexity, size and cost of equipment
© 2014 Tom Ferguson
Good Luck!
© 2014 Tom Ferguson