exchange of data and models between control centers

College of Engineering and Architecture

Exchange of Data and Models between Control Centers

Anjan BoseWashington State University

Pullman, WA, USA

EPCC WorkshopBled, Slovenia

May 18-20, 2015


West European Power Grid


Balancing Authorities


Communication for Power System

Control Center

RTU RTU RTU

Third Party•Analog measurements•Digital states


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


Distribution Management Systems• 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

10

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


EMS Database• Real-Time Database SCADA measurements Exchanged data Calculated data

• Static Database Connectivity of the grid Limits Model parameters External model parameters

• Historical Database


Data Reliability

• Data Communications Dual (redundant) channels

• Database Backup Checkpoint Bumpless Failover

• Backup Control Center Hot Standby or Shared Responsibility Changing Responsibility

Is this design vulnerable to cyber attacks?


Model Maintenance

Static Database Updating• Internal Model Rigorous procedure

• External Model Exchange models in timely manner Requires data standard (CIM?) Requires standard synchronized procedure

across interconnection


Real Time Data Exchange

• SCADA data from neighbors All or selected? How often?

• For what applications? Operator visibility

• Match with external model displays• External outage data should be quick State Estimation

• Match with external model• Update data before each SE run


Data Exchange Vertically

Between EMS and DMS• From DMS Generation on distribution feeders Dynamic load availability Aggregated or individual measurements?

• From EMS Control signals for load response Control signals for distributed generation

How about the customer side (microgrids)?


When PMUs Proliferate• Data rate is two magnitudes higher• High bandwidth network communication needed• Faster applications will be available E.g. SE can be run at 30-60 Hz

• PMU-based controls can be as fast as protection• Wide-area protection and control• Exchange of PMU data already important• Do we need to centralize all PMU data at the

control center?


PMU Data Movement• PMU data communication Data should reach application as and when

needed Not all data need to go to all applications

• Applications don’t have to be at the control center and can reside at substations

• Fast applications like protection and control should have the necessary static data at the application computer


Proposed Communications


Each Application – Different Data• Monitoring at the control center Needs all data points But at slow rates (every few seconds)

• Special Protection Schemes Needs few data points But at fast rates (many times a second)

• Each application must access this data in a different way Moving real time data from source to application

is a complex optimization task


Basic GridStat Functionality

Publishers Subscribers

AreaController

Management Plane

Area ControllerLoad Following

…

Generator

ISO

…

Wide Area Computer Network

(Data Plane)

QoS Control

QoS Meta-Data

US/EU-WideMonitoring?(future??)

QoS Requirements

PMU


Data Exchange Issues• Real time data base must be distributed Large amounts of calculated data must be part of

this data base• Static data base must be distributed• Historical data base will require still another design• Substation data bases and system level data bases

have to be coordinated• All data bases in the same interconnection will

have to be coordinated• Standards will be key

exchange of data and models between control centers

Documents