oncor electric delivery company llc smart grid demonstration project – dynamic line rating (dlr)...

Oncor Electric Delivery Company LLC

Smart Grid Demonstration Project – Dynamic Line Rating (DLR)

June 25, 2010Justin JohnsonERCOTReliability Operations Subcommittee Meeting

Oncor Electric Delivery Company LLC

Tension Based Dynamic Rating Technology

Justin Johnson ERCOT ROS Presentation 06/25/2010 3Oncor Electric Delivery Company LLC

Dynamic Line Rating

Transmission Line Ratings are governed by:

Current flowing in the conductor

Conductor size and resistance

Ambient weather conditions:

– Temperature

– Wind speed and direction

– Solar radiation


Ambient Temperature:

– 2oC fluctuation +/- 2% capacity,

– 10oC drop in ambient + 11% capacity

Solar Radiation:

– Cloud shadowing +/- a few percent,

– Total eclipse + 18% capacity

Wind increase 1 m/sec:

– 45° angle ~ 18% capacity

– 90° angle ~ 23%capacity

How Weather Conditions Affect Ratings (Illustrative Only)


What to Monitor?

Dead-end Dead-end

Suspension Suspension Suspension

Tension increases in spans cooled by wind,

and decreases in spans not cooled by wind…..


Tension Monitoring - Dynamic Line Rating

Tension Equalizes

Suspension insulator strings swing to equalize horizontal conductor tension

Monitoring the conductor’s tension solves the problem of varying winds and exposure along the transmission line.

A conductor’s tension is directly related to the average temperature of all the spans in the line section.

That temperature is directly correlated to the conductor sag and clearances.

Dead-end Dead-end

Suspension Suspension Suspension


Know true line capacity in real time

Improve system reliability

Optimize grid utilization

Dynamic Line Rating Concepts (Illustrative Only)

Dynamic Line RatingDesign Isotherm


Line was operating within limits in accordance with operating standards

Without DLR, this event must be reported as a violation

The operator would have been forced to move the grid off its optimum dispatch

Dynamic Rating

Actual Load

Static Rating

Impact On Transmission Grid OperationsExample Of Safely Managed Contingency


LOCATION OF INSTRUMENTED CIRCUITS

Study Area in Critical Congestion Zone

45 Loadcell Tension Monitoring Units

8 Master Locations Feeding into SCADA


DLR Smart Grid Demonstration

Project Goal: Increase available capacity on a known congested and constrained transmission path and remove existing commercial constraints to implementing DLR technology

Existing Commercial Constraints Include:

• Clear Demonstration that DLR Technology is Reliable

• Utility Planners Understand the Cost Structure and Benefits

• Interoperability with Utility Transmission Management Systems


PROJECT OBJECTIVES

Operational Objectives

Relieve congestion and transmission constraints

Gain operational knowledge of DLRs for wide scale deployment

Ensure that safety code clearances are not impacted

Demonstrate that multiple monitoring units can be integrated into operations

Identify/quantify other operational limits that may impact ability to raise ratings


PROJECT OBJECTIVES

Demonstration Objectives

Extrapolate the impact of DLRs on the study’s transfer path to entire ERCOT region

Determine a methodology to release day-ahead ratings

Develop user friendly tools for the operator to manage improved WASA


PROJECT OBJECTIVES

Economic Objectives

Quantify economic value of released transmission capacity to market

Estimate the savings associated with deferral of rebuilding, reconductoring, or building new circuits

Quantify the total costs of implementing this type of DLR


Integrated Dynamic Line Rating Systems

• Tension-based Dynamic Line Rating System for overhead transmission lines

• Tension resolves all environmental factors for accurate results

• Best way to capture spatial variability of wind, sun, air temperature

• Captures as built, as aged condition of line

• Communicates with utility’s Energy Management System


Solid stainless steel construction.

Sized to match maximum tension

Real Time Rating - Loadcell Monitors Tension


Real Time Rating – Communications Package

Reads conductor tension, net radiation temperature, ambient temperature

Communicates with substation via spread spectrum radio

Solar powered


Integrated Dynamic Line Rating Systems

SCADA/EMS Master

Existing SCADA protocol

over substation RTU channel

(RS232/485)

License free

Spread Spectrum Radio

IntelliCATTM

for Windows

ICCP or MODBUS protocol

CAT-1™ and line load data from EMS

Substation

Control Center

Transmission Line

Operator’s Console’

CAT-1TM Remote Monitors

CATMasterTM

Base Station

Line capacity and temperature to EMS


MAJOR PARTICIPANTS

• Oncor

Purchase DLR equipment and manage project

• The Valley Group, a Nexans company

Provide DLR equipment

• Siemens Energy, Inc.

Integrate DLR technology into Oncor’s TMS system

• Chapman Construction Company

Install equipment on designated circuits

• Southwest Research Institute

Perform independent analysis


Initial Device Installation

PROJECT TIMELINE

2010

Qtr 1

2011 2012 2013

Qtr 2 Qtr 3 Qtr 4 Qtr 1 Qtr 2 Qtr 3 Qtr 4 Qtr 1 Qtr 2 Qtr 3 Qtr 4 Qtr 1 Qtr 2 Qtr 3 Qtr 4

Design/Initial Procurement

Fine-tune Initial Device Output

Terminal Upgrades

Remaining Device

InstallationFinal Report Submitted to

DOE

Project Studies

Reporting (Quarterly to

DOE)


Summary

• Target Completion is 2nd Quarter 2013

• Provides two years of summer peak data

• Will provide a “roadmap” for other utilities to follow - study will be public

• Success Factors include increasing transmission capacity and removing existing commercial constraints to DLR technology

• All eight circuits should be instrumented by end of this year

oncor electric delivery company llc smart grid demonstration project – dynamic line rating (dlr)...

Documents

scada slide

contingency slide

true line capacity

line section

deadend suspension slide

conductors tension

capacity wind

horizontal conductor