present and future electric power...

College of Engineering and Architecture

Present and Future Electric Power Grid

Anjan Bose

Washington State University Pullman, WA

MIT Washington Seminar Series Bethesda, MD

October 8, 2013


THE INTERCONNECTED GRID

• Economics Transfer electric energy from areas where it

is cheap to where it is expensive. Electricity trading dates back to the beginning

• Reliability Neighbors can back up each other. The

cost of redundancy is shared.

Grid Tech Team Grid Tech Team

The GTT recognizes that the line between T & D is blurring, creating a need to prepare for how this changes the grid space

Institutions and other drivers are important to consider with a comprehensive RD&D strategy

GTT Space (outlined in red)

DOE GTT Space


The Past (before 1960s)

• Hard wired metering • Ink chart recording • Light and sound alarming • Hard wired remote switching • Analog Load Frequency Control (1930s) • Economic Dispatch (1950s) • ED was first to go digital


The Present (since 1960s) • The digital control center (SCADA-AGC) • The RTU to gather digital data at substation • Comm. channel from sub to control center (CC) • The SCADA The Data Acquisition from RTU to CC The Supervisory Control signal from CC to RTU

• The screen based operator display • Automatic Generation Control (AGC) The digital algorithm for ED The digital version of LFC


Communication for Power System

Control Center

RTU RTU RTU

Third Party •Analog measurements •Digital states


The Present (since 1970s) • The Energy Management System (EMS) • State Estimation (SE) • Static Security Analysis (n-1) • Dynamic Security Analysis (stability) Transient, Oscillatory, Voltage

• Optimal Power Flow based analysis Preventive Action calculation Corrective Action calculation


Evolution of Computer Architecture

• Special real time computers for SCADA-AGC • Mainframe computer back ends for EMS • Redundant hardware configuration with checkpoint

and failover • Multiple workstation configuration Back-up is more flexible

• Open architecture initiated • CIM (Common Information Model) standard

Eastern Interconnect Control/Monitoring Center

RC1

Sub1 Sub10

0

RCi RC10

Act1-10 Sen1-100

Subk

… … … …

CC1

CCj

CC10

… …

… …


West European Power Grid


XinJiang Autonomous

Region

South

Central East

Northwest

North

Northeast China Grid

1 BTB HVDC

3 HVDC

1 500kV AC

2 parallel 500 kV AC

1 HVDC

Tibet


India Grid


Monitoring the Power Grid

• Visualization Tabular, graphics

• Alarms Overloaded lines, out-of-limit voltages Loss of equipment (lines, generators, comm)

• State estimator • Security alerts Contingencies (loading, voltage, dynamic limits) Corrective or preventive actions


Control of the Power Grid • Load Following – Frequency Control Area-wise Slow (secs)

• Voltage Control Local and regional Slow to fast

• Protection Mostly local, few special protection schemes Fast

• Stability Control Local machine stabilizers Remote special protection schemes Fast


What is a SMART Grid?

• Self-heals • Motivates and includes the consumer • Resists attack • Provides power quality for 21st century needs • Accommodates all generation and storage options • Enables markets • Optimizes assets and operates efficiently


Substation Automation • Many substations have Microprocessor based devices (IED) Data acquisition at faster rates (30-60 Hz) Digital protection and control systems Remote setting capabilities

• Data can be time-stamped by satellite Measure magnitude and phase angle (PMU)

• Local Area Network to control room (LAN) • New substation applications


Phasor Measurements

Super PDC PDC PDC PMU

PMU PMU PMU PMU PMU


Control Center

Substation 1

Measurement1

Measurement i

Substation Server 1

LAN

Executive Unit1

Executive Unit i

Substation 2

Measurement1

Measurement i

Substation Server 2

LAN

Executive Unit1

Executive Unit i

Substation 3

Measurement1

Measurement i

Substation Server 3

LAN

Executive Unit1

Executive Unit i

SPS 1

Power System Communication Systems

SPS 2

R

R

R

R

R

R

R

R

Proposed Communications

Basic GridStat Functionality

Publishers Subscribers

Area Controller

Management Plane

Area Controller

Load Following

…

Generator

ISO

…

Wide Area Computer Network

(Data Plane)

QoS Control

QoS Meta-Data

US/EU-Wide Monitoring? (future??)

QoS Requirements

PMU


DISTRIBUTION AUTOMATION • Measurements along the feeder • Switches, transformer taps, shunt capacitor and

inductor controls • Communications: Radio, Power Line Carrier, Fiber

backhaul • Closer voltage control increases efficiency • Greater switching ability increases reliability • Better coordination with outage management • Sets up for distributed generation, demand

response, electric vehicles or local storage

Pic of one feeder with the new equipment

31

Switched Capacitors

Regulator

Recloser

Francis & Cedar F3, Spokane, WA


Building Automation

• Smart Meters Gateway between utility and customer Communication to utility and home appliances Time-of-day and real-time rates

• Applications Optimize energy efficiency and energy cost Demand response Can integrate generation (roof PV), storage (EV)

• Microgrids


DOE GTT Vision of the Future Grid

A seamless, cost-effective electricity system, from generation to end-use, capable of meeting all clean energy demands and capacity requirements, with: • Significant scale-up of clean energy (renewables, natural gas, nuclear, clean coal) • Universal access to consumer participation and choice (including distributed generation,

demand-side management, electrification of transportation, and energy efficiency) • Holistically designed solutions (including regional diversity, AC-DC transmission and

distribution solutions, microgrids, energy storage, and centralized-decentralized control) • Two-way flows of energy and information • Reliability, security (cyber and physical), and resiliency

Balance several key attributes while recognizing situational differences

Cost-Effective and Reliable

Accessible to New Technologies

Clean and Efficient

Empowered Consumers with Options

Secure and Resilient


The future grid will be vastly more complex than the one we have today

Grid operators must be able to understand implications of events

Grid operators must be able to respond appropriately to events

Institutional factors guide actors’ behavior

Grid operators must be able to see events coming

DOE GTT Framework – Grid Interdependencies


DOE GTT Roadmap – Objectives • Developing the Future Grid Operating System

(Transmission) • Improving the Control of Power Flows (Transmission) • Creating Smarter, More Resilient Distribution Systems

(Distribution) • Integrating Multiple Systems and Technologies

(Distribution) • Designing and Planning the Future Grid (Transmission

and Distribution) • Engaging and Assisting Grid Stakeholders

(Transmission and Distribution)


SOCIETAL GOALS • Economics – Plan and Operate the Grid

optimally • Reliability, Resiliency and Security (physical,

cyber) • Less Carbon – Increase Renewable Resources • More Customer interaction and choice • Flexibility needed for uncertain future • Smart Grid is the enabler – Use more

information technologies


INSTITUTIONAL ISSUES • Reliability standards – need emphasis on best

practices rather than compliance • Transmission planning – who is responsible? • Operational procedures – e.g. data sharing • Market rules – often does not take into account

operational realities • Rate regulation – FERC, state PUCs • Federal or state energy policies


Conclusions

• Holistic systems research approach – not piecemeal for each goal or component

• Ramp up systems research to match investment in components

• Adoption of new technologies in the grid (Realistic test platforms needed)

• Institutional policies updated to encourage technological solutions to meet goals

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