The Smart Grid Power Quality Power Reliability Terry Chandler Power Quality Inc, USA Power Quality...

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The Smart Grid

Power QualityPower Reliability

Terry ChandlerPower Quality Inc, USA

Power Quality Thailand LTDSept 2011www.powerquality.org all rights reserve 1

www.powerquality.org all rights reserve 2

SmartGrid

A smart grid is neither a clearly defined single concept nor a single technology. Rather it is like a basket containing various combinations of balls. The context and the interpretation depend upon the user. • Carnegie Mellon University USA

Utility perspective

Andy Tang, an executive at the PG&E utility in California, “ Smart Grid is not a thing or a specific project. It is about how the utilities leverage technology to enhance their entire portfolio of business processes.”

What is a Smart grid?

“Smart grid” generally refers to a class of technology people are using to bring utility electricity delivery systems into the 21st century, using computer-based remote control and automation.

These systems are made possible by two-way communication technology and computer processing that has been used for decades in other industries.

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Definitions

A smart grid is an umbrella term that covers modernization of both the transmission and distribution grids. http://en.wikipedia.org

Smart Grid is a new industry being built around the modernization of the electrical grid, green power generation and more efficient usage of electrical power.• Terry Chandler, Power Quality Inc Aug 2009

NIST SmartGrid Conceptual model

Why do we need SmartGrid?Improve efficiencies.

SmartGrid changes and PQ Interconnects at multiple levels Changes in the network in real time will

affect many customers and network operations will become more complex.

These will require products to isolate the faults quickly and without network disruption.

Products that can predict failures before the happen or isolate before damage occurs will be in high demand.

Why do we need SmartGrid?Improve reliability!

Sept 8th 2011 a Blackout occurred that affected 5 Million customers in SW USA.• It started at a 500KV substation in Yuma, AZ• It tripped the 500KV line serving San Diego, Ca and

all the border communities in between.• This caused an overload on the remaining

transmission line from Los Angles Area. It tripped.• This removed a large percentage of the load from

the nuclear power station North of San Diego. It shut down two generators

• Blackout lasted from 6 hours to 24 hours

Approximate area of blackout

5 Million people, blackout for up to 12 hours.

Blackout Sept 8th San Diego Ca. USA (Cause?)

The Arizona Public Service Co. worker was switching out a capacitor, which controls voltage levels, outside Yuma, Ariz., near the California border. Shortly after, a section of a major regional transmission line failed

Cost of reliability for this outage

$100 million $ = 3 Billion Thai Baht

Could the SmartGrid have prevented this Massive Blackout?

Yes, (if not prevented it could have reduced the impact and dramatically improved the restoration time)

How? Communication!• between the loss of transmission line and

automatic load shedding. • between the North Transmission line and

Nuclear generators that the load would be restored quickly.

• Communication to users that power would be restored quickly.

What is Power Quality?

The characteristics of the supply voltage and the electrical system that affect the performance of the load

The characteristics of the load that affect the electrical system or other loads..• Terry Chandler PQI 1995

June of 2008, the U.S. Department of Energy list for Smart Grid

1 Optimize asset utilization and operating efficiency.

2 Accommodate all generation and storage options. (Green)

3 Provide power quality for the range of needs in a digital economy.

4 Improve reliability (outage seconds/minutes)

Power reliability = outage > than 2 secondsPQ = the value of voltage and other parameters

PQ/PR issues for Utility side As Bill Howe presented, in general improving

reliability decreases the Quality of Supply.• Voltage sags increase due to network connections• Harmonics will change when switching sources

Voltage transients• Lightning (better protection)• Switching grid will increase• Power Factor Capacitor switching Increase

Voltage unbalance, change as source changes Frequency? worse if microgrids are islanded Phase shifts maybe more frequent when

switching sourceswww.powerquality.org all rights reserve 18

Event Avoidance to improve PR/PQ

Remote load profiling/management

Automatic Grid event diagnostics

Advanced data analysis

Grid condition sensing and predictive response

Self-Healing Grid (improve PR)

Improved asset management/visibility

Real-time grid condition monitoring• Increase reliability, increase information

Automated grid switching to improve reliability and reduce risk of major blackouts.• It will decrease the Quality of Supply by

increasing the number of switching transients

Self healing grid

Meters as a sensors for the SmartGrid

Transformer load management, near real time

Condition-based crew dispatching with Automatic Fault locating

Advanced Meter Infrastructure• Meters, Revenue, Grid monitors & PQMS• Meter with load connect/disconnect• Automatic outage notification• Two-way communications with meters• Automated meters a critical role in the

Smart Grid architecture as sensing devices.

Today’s Grid vs Smart Grid

Compare the reliability

Power not available9's Seconds Minutes2 99.0000000% 315,360.00 5,256 3 99.9000000% 31,536.00 526 4 99.9900000% 3,153.60 53 5 99.9990000% 315.36 5 6 99.9999000% 31.54 7 99.9999900% 3.15 8 99.9999990% 0.32

Fixed line telephony

How will Smart Grid affect Power Quality

Frequent switching of the grid will• Significant increase of switching

transients (until solid state switching devices are used)

Sensitive loads will experience an increase in transients

• Voltage imbalance/unbalance will change with switching alternate sources

Harmonics affected by Smart Grid Voltage Harmonic levels

• Voltage distortion is a function of Harmonic load current and the source impedance.

As the SmartGrid switches between sources it will change the source impedance. This will cause the Voltage distortion level to change when the Grid Switches.

SmartGrid and voltage sags

Interconnection of distribution substations

Increases voltage sags incidents at that voltage level.

PQ changes with SmartGrid

PQ parameter Transition to netgrid Smart Grid fully implementedV Harmonics Increase decrease or return existing levelVoltage transients Increase decrease or return existing levelVoltage imbalance Increase decrease or return existing levelVoltage Phase Shifts Increase decrease or return existing levelVoltage Sags Increase depends on implementation

Conclusions Short term affects As the grid changes from Hierarchal to

network configuration the voltage sag incident will increase.

The Voltage harmonics will change frequently as the source impedance changes when the SmartGrid switching.

Voltage waveform transients will occur during the switching and can be sever if the new source is at a different phase angle than the existing source.

Conclusions Long Term

GridSwitching will become more sophisticated to switch only at zero crossing and when in phase.

Network design will change to reduce voltage sag depth and duration.

Short and medium term Power Quality will deteriorate

Long Term Power Quality should improve to existing levels or better

References http://

www.leonardo-energy.org/what-definition-smart-grid

http://www.utilitiesproject.com http://www.smartgridnews.com/artman/pu

blish/article_177.html www.Gridwise.org

Information sources for SmartGrid

http://www.sgiclearinghouse.org/ http://www.smartgrid.gov/ http://

www.nist.gov/smartgrid/sgip-072611-factsheet.cfm

http://www.sgiclearinghouse.org/LearnMore

Thank You

Terryc@powerquality.org Terryc@smartgridasia.us

The Smart Grid Power Quality Power Reliability Terry Chandler Power Quality Inc, USA Power Quality...

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