Utilizing AMI Infrastructure to Support Distribution Automation - - PowerPoint PPT Presentation

Utilizing AMI Infrastructure to Support Distribution Automation Applications

Smart Grid Distribution Automation Conference

• Nov. 2-3, 2011, Raleigh, NC

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"Load/voltage modeling of distribution systems; a system identification approach," Gorman, M.J.; Civanlar, S. ; (Grainger, J) Southeastcon '89. Proceedings. Energy and Information Technologies in the Southeast., IEEE , vol., no., pp.386-389 vol.1, 9-12 Apr 1989

Abstract: A system identification method is proposed which can be used to characterize the distribution system load as a function of the substation voltage. The primary objective of this technique is to capture the dynamic variation of the composite system load on distribution feeders so that the most effective substation voltage level can be obtained and applied to conserve energy over specified control periods. The proposed system identification method is implementable on actual distribution systems by utilizing existing capabilities of the distribution automation hardware. Also, the impulse response of a space heating load is identified using the proposed technique to demonstrate the applicability of the identification method.

History Lesson

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• Libya October 31: Libya's interim authorities have named Tripoli

academic Abdurrahim al-Keib as the new prime minister.

• Papers – listed as El-Kib
• Grainger interview:

http://www.alumniblog.ncsu.edu/2011/11/02/nc-state-professor- recalls-student-who-now-leads-libya/

Volt/VAR Researcher in Spotlight

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• Volt/VAR Control Retrofit Paths
• Utilization of “AMI Infrastructure”
• Enhancing Meter Functionality
• Considerations for realizing a set of bellwether voltage

metering functions

– Operational – Nonoperational

• Bellwether meter configuration and reporting
• Conclusions

Topics

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• How to proceed with different starting points as far as existing level
• f automation?
• What about the small utilities, munis, coops (3000 entities)?
• What type of Volt/VAR control makes sense for:

– A 5,000 meter utility? – A 25,000 meter utility? – A 250,000 meter utility?

• How should need for scalable solution approaches impact AMI/DA

product offerings?

• Can AMI Infrastructure installation facilitate a “DA Catch Up”?

Volt/VAR Retrofit Paths

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Possible Starting Point

• No top of feeder measurements, non-microprocessor-based relay
• Switched capacitors sparingly used
• Power factor not properly corrected
• Possible voltage regulation problems
• Local control on switched capacitor, no upgrade path for

communications or remote control

• Local control on substation and line regulators, no options for remote

control

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• Install basic

substation automation components

• Upgrade feeder relay

to microprocessor- based – get richer set of feeder measurements

• Upgrade voltage

regulator control – SCADA compatible

• Add substation

points to Supervisory Control and Data Acquisition (SCADA)

• r historian

Adding the Substation Automation

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• Upgrade

feeder controls

• Install

Radios

• Link to

Head End for collecting data

• Interface to

SCADA

Upgrading Feeder Controls

Substation Gateway/PLC

SCADA

Voltage Regulator Control Regulator Control

Substation

Voltage Regulator Feeder Relay Switched Capacitor Control DA Radio Module DA Radio Module

DA Head End

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• DA endpoints

need to support a wide variety of automation applications (greenfield and retrofit)

• Need flexibility on

communications type (ex. Licensed Radio and Cellular versions)

• Faceplates?

DA Endpoints

Intelligent Electronic Device Communications Module MicroRTU Capacitor Bank Control Fault Current Indicator Receiver

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DA Radio Module Interface Example

• DA Radio

Module mounted on inside of cabinet.

• SCADA

connection (via DNP) for data monitoring and remote switch control.

• Pass Through

for device configuration program.

DA Radio Module DA Device Controller Direct Pass Through SCADA Connection

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• Addition of End of

Line voltage measurements

• Decentralized or

Centralized Control

• Engineering effort

for model building, configuration and testing

• How many EOL

points are needed?

Enabling Volt/VAR (DA Only)

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Voltage Range Targets

• Allowable Voltages defined by

ANSI Standard C 84.1 – 1995 “Electrical Power Systems and Equipment – Voltage Ratings.”

• Feeder Voltages typically at

high end of utilization range.

• Volt/VAR control used to both

drop utilization voltage and narrow voltage deviation range.

• Meter measurements could

ensure that limits not violated.

Voltage 128 126 124 122 120 118 116 114 112 110 108

A Service A Utilization Typical Range VVC Range

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Volt/VAR with AMI Infrastructure

• DA Radio Modules

provide communications interfaces to capacitor controls, line regulator controls, etc.

• DA head end links

endpoints with SCADA and Volt/VAR Control.

• Bellwether meters

provide voltage data to AMI head end.

• AMI head end that

receives voltage data from bellwether meters and forwards this data to the target Distribution Management System application(s).

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• Licensed RF
• Multi-Channel Base Stations
• Concurrent Parallel Channels
• Electric, Water, Gas & DA
• DA Traffic put on channels

separate from AMI to avoid traffic degradation

AMI/DA Channelization Scheme

DA Normal Read

AMI Poll

ALARM

AMI Normal Read

DA Poll

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• Traditional meter functionality is

measurement of Energy (kWh), Peak kW, Reactive Power (kVAR), interval data, instantaneous voltage ping.

• Meter has enough processing power

to perform other measurement functions.

• Voltage samples can be processed to:

– Voltage averages over longer defined intervals (seconds to minutes). – Voltage averages/minimum/maximums

• ver defined intervals.

– Voltage power quality sags and swells magnitudes and durations.

Enhancing Meter Functionality

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• Operational

– Time-Schedule Reporting – Report on Exception – Unsolicited Alarm Reporting

• Nonoperational

– Voltage Interval Data – Voltage Power Quality Data

Data Types

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• Voltage averages over a predefined interval at a fixed report

frequency

• Ex. (1:01:13; 122.5V), (1:06:22; 122.4),(1:011:11, 121.9)
• Uplink only, no acknowledgement from head end

Time-Scheduled Reporting

122 122.5 123 123.5 124 124.5 125

5 Min Ave Xmit 10 Sec 5 Min Max 5 Min Min

Example of intermittent voltage due to photovoltaics

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• Only send voltage if change exceeds a threshold change to reduce

traffic

• Ex. (1:01:13; 122.5V), (1:011:11, 121.9)
• Send “heartbeat” report to verify meter still communicating
• Advantage is reduction in communications traffic

Report on Exception

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• Only send voltage data (or just alarm) if value goes below or above

threshold

• Ex. (1:01:15; 118V)
• If only alarm status set, can follow up with voltage ping

Unsolicited Alarm Reporting

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• Provide distribution planners with indication of where voltage

problems are occurring with time stamps

• Voltages calculated over predefined window (ex. 1 minute) – need

window compatible with evaluating volt/VAR control

• Voltage average, minimum and maximum over fixed interval, such as

1 hour

• Transmit voltage interval data every 24 hours

Voltage Interval Data

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• Provide distribution engineers with voltage quality data
• Trigger meter recording on voltage sags and swells
• Compute voltage sag/swell magnitude, duration with timestamp
• Transmit on threshold or hold for predefined time period

Voltage Power Quality Data

0.02 0.04 0.06 0.08 0.1

• 1
• 0.5

0.5 1 Time (sec) Voltage (pu)

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Bellwether Meter Configuration & Reporting

• Bellwether meters are user selectable (ex. 1 or 2 meters per lateral).
• Assume small number (1-2%) of meters utilized for near real-time feedback.
• Measurement data routed to volt/VAR client application.

Firewall

AMI Transceiver Bellwether Provisioning Messages

User Interface for Bellwether Configuration Firewall

Cryptography Keys AMI Head End Electric Meter Measurement Data Messages

Backhaul

Bellwether Meter Configuration Client Distribution Management System Application Meter Data Archiving

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• Minimize need for expensive End of Line feeder measurements.
• Can easily relocate bellwether meter points.
• Voltage interval data can be utilized to:

– Plan for location of bellwether points – Determine if voltage violations are already occurring – Evaluate effectiveness of control scheme

• Have more confidence in setting lower voltage targets if can be

assured that violations are not occurring.

• Use of a large of measurements might allow for simpler control

strategies.

Advantages of Bellwether Functionality

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• New to Volt/VAR Control? – Consider spending some time in the

library.

• More to Volt/VAR control than just radios and logic, need to

consider complete infrastructure build-up and other supporting solution components.

• Need to factor in the potential synergy between AMI projects

and Volt/VAR control – it’s more than just a DA app.

• Meters are more than cash registers and outage detection

devices – a great deal of potential sensor input still waiting to be tapped.

Summary

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QUESTIONS?