1. The U.S. Electrical Grid
Design
Function
Issues

2. Electricity Grid:
The ‘traditional model’ of electric power generation and delivery :
Based on construction of large, centrally located power plants
Power plants located on hubs
Hubs near major electrical load centers
Ultimate Grid Purpose = Deliver power from generation source to users.

3. Some Factors that influence Power Plant siting
Location of load centers –vs- Availability of fuel resources
Need for a cooling water source
Fundamental for operation of conventional fossil fuel plants
Environmental considerations
Larger influence than ever
Global Climate Change, Endangered Species Act, Wilderness areas, Ocean Health, etc.
Carbon Footprint Concerns

4. More power plant siting factors
Geographical/Economic considerations
Plant located close to coal mines to minimize the cost of shipping coal… (A Local Issue?!)
Hydro plants in dams at water source, may be far from cities
Social, political considerations
View-shed, Public demand/acceptance
Political clout and will.
Special Interests Pro/Con

5. Grid infrastructure Transmission systems
High-voltage to minimize electrical losses
138 kV to 765 kV, most A/C
Carry electricity from the power plants
Transmit from source to user, a few miles to thousands of miles

6. Electrical Substations
Substation transformers "step down" the transmission voltages
Switchgear and circuit breakers to protect the transformers and the transmission system from electrical failures on the distribution lines.

7. Distribution systems Lower-voltage
Draw electricity from the transmission lines
More Transformers located along the distribution lines further step down the voltage to 120 V or 240 V for household use.
Distribute electricity to individual customers.
Circuit breakers located on distribution lines isolate electrical problems (e.g. short circuits caused by downed power lines).

8. Grid Architecture and Function
The transmission system is central trunk of the electricity grid.
Thousands of distribution systems branch off from this central trunk
Distribution systems fork and diverge into tens of thousands of feeder lines reaching into homes, buildings, and industries.
Power flow to the distribution systems determined by the power flow through the transmission systems.

9. Grid Architecture and Function
Most references to “power grid" really mean the transmission system.
Grid nomenclature accurate: Transmission lines run from power plants to load centers and from transmission line to transmission line
Redundant system helps ensure smooth flow of power
If a transmission line is taken out of service in one part of the power grid, the power can usually be rerouted through other power lines to continue delivering power to customers.

10. Grid Architecture and Function
Grid permits power from many power plants to be "pooled" in the transmission system
Each distribution system draws from this pool
Networked system helps achieve a high reliability for power delivery because any one power plant that shuts down will only constitute a fraction of the power being delivered by the grid.
Networked system permits a diversity of power sources
Coal
Nuclear
Natural gas
Oil
Renewable energy sources

11. Energy Flow

12. U.S. Power Grids
No "national power grid" in the United States: Actually there are 3 main power grids:
The Eastern Interconnected System, or the Eastern Interconnect
The Western Interconnected System, or the Western Interconnect
The Texas Interconnected System, or the Texas Interconnect.

15. The 10 North American Electric Reliability Council (NERC) regions
ECAR — East Central Area Reliability Coordination Agreement
ERCOT — Electric Reliability Council of Texas
FRCC — Florida Reliability Coordinating Council
MAAC — Mid-Atlantic Area Council
MAIN — Mid-America Interconnected Network
MAPP — Mid-Continent Area Power Pool
NPCC — Northeast Power Coordinating Council
SERC — Southeastern Electric Reliability Council
SPP — Southwest Power Pool
WSCC — Western Systems Coordinating Council

16. U.S. Power Grid Operations

19. Controlling the Grid Electricity is generated as it is used.
There is very little ability to store electricity.
Because of this instantaneous nature, the electric power system must constantly be adjusted to ensure that the generation of power matches the consumption of power.
On continental U.S. power grids, roughly 150 Control Area Operators serve this function by using computerized control centers to dispatch generators as needed.

20. Grid Operation
Responsibility for electric grids has traditionally rested with electric utilities
Control Area Operators run the grid within their control areas
Each utility has responsibility for the operation of the electrical grid within its service area

21. Grid Operation, cont.
Some states have moved to pass the control of the grids to independent system operators, or ISOs.
Utility control of the grid has been viewed as a conflict of interest.
California ISO controls the transmission grid for California.
ISOs also exist in Texas and New England.
Ownership of the transmission and distribution systems may be retained by the utilities or be passed off to independent transmission companies ("TransCos"), in which case the utility effectively becomes a distribution company ("DisCo").

22. Electric Control Area Operators — Continental United States, 1998.

23. U.S. Grid Interconnections
The Eastern and Western Interconnects have limited interconnections with each other
Texas Interconnect is only linked with the others via direct current lines.
Both the Western and Texas Interconnects are linked with Mexico
Eastern and Western Interconnects are strongly interconnected with Canada.
All electric utilities in the mainland United States are connected with at least one other utility via these power grids.

24. Hawaii and Alaska grid systems
Much different than those on the U.S. mainland.
Alaska grid system connects only Anchorage, Fairbanks, and the Kenai Peninsula
The rest of AK depends on small diesel generators, or minigrids
Hawaii depends on minigrids to serve each island's inhabitants.

25. Electrical generation sources divided into three categories
Baseload power plants, which are run all the time to meet minimum power needs
Nuclear plants are nearly always operated as baseload plants because they are most stable at full power.
Peaking power plants, which are run only to meet the power needs at maximum load (known as "peak load“ or “cyclilng”)
Peaking plants are generally the most expensive plants to operate. In many cases, these are small, older coal- or oil-fired plants, although gas turbines can also be used as peaking plants.
Intermediate power plants, which fall between the two and are used to meet intermediate power loads.
Intermediate plants are well-suited to changing power loads (called "load following"); gas turbines can be used as intermediate plants.
E.G. Basin Creek 50 MW NG Plant near Butte, Dave Gates Generating Station east of Anaconda

27. Existing Grid Designed Around Large Centralized Power Plants
Premise of the Design of our electric power industry:
Large, centralized power plants could achieve economies of scale that would make them the least expensive source of electricity.
This principle not necessarily still accepted
Small, efficient gas turbines can produce inexpensive electricity on a relatively small scale.
Distributed generation from renewables may play increased role
Siting, permitting, and construction delays and costs for large-scale power plants have made them less competitive.

28. A little history: 1980’s Power Crunch
Around 1985, electric utilities began to anticipate increased competition
Companies looked to cut costs and avoid debt that would make them uncompetitive
Large power plants involving investments of billions of dollars viewed as unacceptable risks
Utilities avoided new power plant investments
Demand-side management programs (programs to encourage energy efficiency and load reduction) became popular as one alternative to power plant construction.
By the time wholesale electricity competition began in the United States in 1996, utility investment in power plants had slowed considerably.
Wholesale competition changed the way utilities operate
With restructuring imminent, electric utilities also reduced their investments in demand-side management because these investments seemed counter to their goals.

29. Electric Restructuring
Electric restructuring; California and several other states.
California 1996
Montana Deregulation in 1997
Some states with low rates were reluctant to pursue restructuring.
Efforts to establish restructuring on a federal level were not successful.
Uncertainty in the industry dragged on, further discouraging utility investments.
Load growths in the range of 3% per year also created little incentive to build new power plants
In the Northeast, the option of importing inexpensive hydropower from Canada was a simple and inexpensive solution to growing power needs.
Lack of generation growth led to tight electricity supplies in the United States, particularly in California, circa 2000.
A drop in hydropower production in the Pacific Northwest contributed to these tight electricity supplies.
NEW investments in Electrical Generation now occurring.
Wind, Solar, taking the lead

30. Power Quality and Reliability Issues
Power quality is a concern for today's power grid and the loads it serves.
Computer equipment, in particular, is sensitive to power quality problems
High power quality is important to many commercial and industrial firms and the average homeowner.
Renewables do not always provide best power quality due to fluctuating nature

31. Some Power Quality Problems
Decaying oscillatory voltages — The voltage deviation gradually dampens, like a ringing bell. This is caused by banks of capacitors being switched in by the utility.
Commutation notches — These appear as notches taken out of the voltage wave. They are caused by momentary short circuits in the circuitry that generates the wave.
Harmonic voltage waveform distortions — These occur when voltage waves of a different frequency—some multiple of the standard frequency of 60 cycles per second—are present to such an extent that they distort the shape of the voltage waveform.
Harmonic voltages — These can also be present at very high frequencies to the extent that they cause equipment to overheat and interfere with the performance of sensitive electronic equipment.

32. Power Quality
The most severe power quality problem is voltage surge caused by a lightning strike.
Other power quality problems include:
Voltage sags and swells — The amplitude of the wave gets momentarily smaller or larger because of large electrical loads such as motors switching on and off. Voltage sags are the most commonly experienced power quality problem among electronic and computer equipment users.
Impulse events —glitches, spikes, or transients; voltage deviates from the curve for a millisecond or two (much shorter than the time for the wave to complete a cycle). Impulse events can be isolated or can occur repeatedly and may or may not have a pattern.

33. Power Quality
Other power quality problems may also be considered reliability problems because they occur when the transmission system is not capable of meeting the load on the system.
Brownouts are a persistent lowering of system voltage caused by too many electrical loads on the transmission line.
Blackouts = a complete loss of power.
Unanticipated blackouts are caused by equipment failures, a downed power line, a blown transformer, or a failed relay circuit.
Although normally limited by design to a small geographic area, blackouts have been known to affect wide regions of the United States.
"Rolling" blackouts
intentionally imposed upon a transmission grid when the loads exceed the generation capabilities. By blacking out a small sector of the grid for a short time, some of the load on the grid is removed, allowing the grid to continue serving the rest of the customers. To spread the burden among customers, the sector that is blacked out is changed every 15 minutes or so—and hence, the blackouts "roll" through the grid's service area.

34. Possible Future Power Solutions
METHOD 1: Use the traditional utility paradigm:
Build more power plants, update existing plants
Beef up the transmission system
allow power to be shipped to where it is needed.
Create legislation to encourage investment in both approaches
(these actions are moving forward in many states)
These investments could be encouraged via a National Energy Plan.

35. Possible Future Power Solutions
METHOD 2: Incorporate more Distributed energy (DE) resources
DE investments bring power solutions directly to user locations
Reduced need for long-distance transmission of power.
Reduce reliance on transmission and distribution systems by providing customer-specific solutions at the point of need
Each DE system represents a relatively small investment that can generally be installed within a short timeframe.
DE can lessen the financial risk of investment and can be more responsive to changing load growth.
*Combinations of these two major themes are likely
*All Solutions benefit from efficiency increases

36. Other Power Grid Concepts
There are a variety of approaches to improving the operation of the electricity grid, some of which involve replacing it entirely in specific locales. All of these approaches are motivated by power reliability and/or quality concerns, and all incorporate Distributed Energy.
Minigrids
Power Parks
DC Microgrids
Flexible Alternating Current Transmission Systems
Electrical Load as a Reliability Resource
SMART GRID

37. Smart Grid & Integration of Renewable Energy Resources (Portions adapted from a presentation by SmartGrid IIT, Johdpur, India)

38. What is Smart Grid ?
The Smart Grid is a combination of hardware, management and reporting software, built atop an intelligent communications infrastructure.
In the world of the Smart Grid, consumers and utility companies alike have tools to manage, monitor and respond to energy issues.
The flow of electricity from utility to consumer becomes a two-way conversation, saving consumers money, energy, delivering more transparency in terms of end-user use, and reducing carbon emissions. ,

39. What is Smart Grid ?
Modernization of the electricity delivery system so that it monitors, protects and automatically optimizes the operation of its interconnected elements – from the central and distributed generator through the high-voltage network and distribution system, to industrial users and building automation systems, to energy storage installations and to end-use consumers and their thermostats, electric vehicles, appliances and other household devices.
The Smart Grid in large, sits at the intersection of Energy, IT and Telecommunication Technologies. 39

40. Key Elements of Smart Grid
Transmission Optimization
Demand Side Management
Distribution Optimization
Asset Optimization

41. SMART GRID IN TRANMISSION41

42. Technology Integration & Grid Management
Need for development of Smart Grid having features like-
Phasor Measurement Technique
Wide Area Measurement (WAM)
Flexible AC Transmission System (FACTS)
Adoptive Islanding
Self healing Grids
Probabilistic and Dynamic Stability Assessment
Distributed and autonomous Control 42

43. Sidebar…
A phasor measurement unit (PMU) or synchrophasor is a device which measures the electrical waves on an electricity grid, using a common time source for synchronization. Time synchronization allows synchronized real-time measurements of multiple remote measurement points on the grid. In power engineering, these are also commonly referred to as synchrophasors and are considered one of the most important measuring devices in the future of power systems.[1] A PMU can be a dedicated device, or the PMU function can be incorporated into a protective relay or other device.[2]

44. Benefits of PMU Time synchronized sub-second data
Dynamic behavior observing
Directly provides the phase angles (State Estimation to State Measurement)
Improve post disturbance assessment
High data rates and low latency due to computation 44

45. SCADA Vs PMU ~ STATE MEASUREMENT STATE ESTIMATION
SCADA = supervisory control and data acquisition
PMU = Phasor Measurement Units
Network model
State Estimator
SCADA Telemetry
V KV
P MW
Q MVAR
Hz Hz ~
Open
Close
Several Seconds to a Minute
milli secs
to sec
STATE MEASUREMENT
STATE ESTIMATION
Supervisory Control and Data
Acquisition (SCADA) Systems
Phasor Measurement
Traditionally developed for accommodating old information technology regime (Slow communication, data without time stamp)
Made possible for all round development in technologies 45
LD&C_SCADA

46. Overview of Smart Grid 46

47. Advance Metering Infrastructures Adaptive Islanding etc.
Smart Grid in Power Sector
Transmission
Distribution
System Operations
Asset Management
HVDC and UHVAC etc.
Advance Metering Infrastructures
Asset Management etc.
Self Healing Grids
WAMS
Adaptive Islanding etc. 47

48. Smart Grid in Distribution

49. Smart Grid in Distribution
Distribution Automization
Demand Optimaization - Selective Load Control
Operation –Islanding of Micro-grids

50. Distribution Automization/Optimization
Managing Distribution Network Model
Outage management and AMI Integration
DMS & Advanced Switching Applications
Integrated Voltage / VAR Control

51. Demand Optimization Demand Response – Utility
Demand Response – Consumer
Demand Response Management System
In Home Technology enabling

52. Demand Optimization Smart Metering –
Automatic, Time of Use, Consumer Communication & Load Control
Communications : Automated Metering Infrastructure (AMI) – LAN, WAN, HAN
DRMS (Demand Response Management)
In Home enabling technology
Demand in three category:
Immediate, Deferrable, Storable
Customer aggregation & De-aggregation required for Peak shifting

53. Demand Optimization: Advanced Web Portal
Energy Usage Information
Utility Communication
Consumer Enrollment in DR programs
In Home Technology- Availability & Purchase , Device Provisioning

54. Control Center with Service Oriented Architecture (BUS)
Having
GIS (geo-spatial Information Systems),
AMI,
SAP (ERP),
OMS (Outage management System),
DMS (Distribution Management System),
EMS (Energy Management System),
DRMS (Demand Response management System).
Model manager synchronizes GIS data with OMS, DMS & EMS.

55. Expectation of Technology & Solution Partners
To associate and collaborate with Smart Grid players in other parts of globe
Develop local expertise to manufacture and provide support services
Development of CIM
Application Development in India Power Sector Context.

56. Why Smart Grid?
Integrate isolated technologies : Smart Grid enables better energy management.
Proactive management of electrical network during emergency situations.
Better demand supply / demand response management.
Better power quality
Reduce carbon emissions.
Increasing demand for energy : requires more complex and critical solution with better energy management

58. Drivers of Smart Grid Increasing demand:
High Aggregate Technical & Non Technical, Losses:18%-62%
Ageing assets…transformers, feeders etc.,
Grid to carry more power: Need for, Reliability and greater Security
Billing and collections: Profitability of distribution companies
Energy mix: Need for Renewable to reduce carbon footprint

59. Implementation leads to …..
Deliver sustainable energy
Increased efficiency
Empower consumers
Improve reliability
Smart Grid

60. New Technologies for…..
Energy Storage to support a Resilient Smart Grid
(Comparing & evaluating cost competitiveness of:
Compressed air, pumped hydro, ultra capacitors, flywheels, battery tech, fuel cells.)
Smart Grid & Electric Vehicle Integration
(How can electric Vehicle optimize the use of renewable energy resources, improve efficiency)

61. Challenges Faced by Smart Grid
Present Infrastructure is inadequate and requires augmentation to support the growth of Smart Grids.
Most renewable resources are intermittent and can not be relied on (in its present form)for secure energy supply
Regulatory Policies to deal with consequences of Smart Grid; like off peak, peak tariffs and other related matters.
Grid Operation : Monitoring & control

62. Integration of Renewables
Net Zero – Energy / Water / Waste
Green Community – Self Sufficient & Reliant
Judicial Mix of various Technologies and Options for different use
Use or Supply
Draw or Store
Storage Options
Type of Use
Heating /Cooling
Illumination / Ventilation
Machine Operations
Appliance Powering ( Computers / Printers / Copiers / Faxes)
Domestic Appliances

63. Integration of Renewables
Choice of Current
AC or DC
AC – DC
DC – AC
DC – DC
Switches and Disconnects
Availability of Domestic DC Appliances - Power Packs
Connectivity to Grid – Size of Plant, Distance to Consumers
Control Strategy and Methodology – availability of software

64. Some More Resources
cities-adopting-smart-grid-technology