12/10/13 - PowerPoint Presentation

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Homeostatic Utility Control

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Homeostatic Utility Control in Retrospect

J.L. Kirtley Jr.kirtley@mit.edu

Gridwise

Architecture Council

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th

Transactive

Energy WorkshopSlide2

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Homeostatic Utility Control

Arose from an initiative of Fred C. Schweppe

and his colleagues in the late 1970’s

Was actually named by Richard Tabors

Was part of

Schweppe’s

efforts to re-invent the electric utility system

Was intended to make the grid work better

Was developed in the context of regulated public utilities

When first presentation, was rather roundly ridiculed

Has provoked quite a lot of researchSlide3

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There were three basic elements of Homeostatic Utility Control:

Frequency Adaptive Power Utility Regulator (FAPER): Fast controlThe Energy Marketplace

Marketplace Interface to CustomerSlide4

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Frequency Adaptive Power Utility Regulator (FAPER): Fast control

The Energy MarketplaceMarketplace Interface to CustomerSlide5

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FAPER

Intended to replace (or supplement) ‘Spinning Reserve’Fast (virtually instantaneous) controlTakes advantage of ‘average power’ or ‘energy’ type loads

Works only within the hysteresis band of an energy load

Within that band, turns load on or off according to frequencySlide6

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FAPER would help the system, but why would customers want to install them?

There is some expense

Probably negligible impact on comfort of equipment operation

Here is

Schweppe’s

suggestion for compensation

Charge less when frequency is high and more when frequency is low!Slide7

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Later work on FAPERs at MIT: Kevin Brokish

Surprisingly large fractions of consumer loads are amenable to FAPER operationBrokish assumed operation to be a modification of

setpoint

in a hysteresis type controlSlide8

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Brokish

recognized

an instability that can arise with a lot of FAPERS controlling loads by switching them on and off

Loads synchronize with each other

Solution is like Ethernet communications: use probabilistic delay

White band is the dead band

Outside dead band, lighter blue is higher probability of switchingSlide9

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More Transactive Energy Work: Olivia

Leiterman on StorageFAPER like action need not depend on frequency

Signals from the utility system can initiate change in interchange

Energy Storage is the ultimate in ‘energy’ type load

Here is some motivation for involving real energy wiggles in ‘ancillary services’Slide11

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‘Power Signal’ could be derived from frequency

Or it could be an area power error signal

Separating high and low frequency signalsSlide12

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Separation of high frequency and low frequency variations

Energy Duration tells what your energy storage is doing

Ramp Duration tells what your other (slower) regulation resources are doingSlide13

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Here is the bottom line:

More to this than can be quickly explained

Longer (slower) frequency cutoff reduces mean ramp rate for thermal units

But it also means more storage energy is requiredSlide14

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Frequency Adaptive Power Utility Regulator (FAPER): Fast control

The Energy MarketplaceMarketplace Interface to CustomerSlide15

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This is the Energy Marketplace as envisioned by

Schweppe

in 1980

Note ‘Utility Generation’ is in the ‘Regulated Industry’ Slide16

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In The Energy Marketplace:

There would be a mix of regulated and unregulated generation

Regulation to ensure return to capital and prevent monopoly pricing

Separate ‘buy’ and ‘sell’ prices for customer generation

‘Time of Day’ pricing was recognized as insufficient

Anticipated automation in customer premises

Recognized that there would be issues with customer acceptance and privacy

And anticipated (maybe incorrectly) that two-way communication with meters might be impracticalSlide17

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Later work on Spot Pricing:

Jiankang Wang

Here we have a pretty generic explanation of why you want to get the final price rightSlide18

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In a deregulated market, System operators must buy electricity and keep the system balanced

Elasticity Matrix describes

instantaneous elasticity of demand

cross-elasticity (from one time period to others)Slide19

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Demand is determined by a balance

Unit Commitment

Economic Dispatch

Price Elasticity predicts change in demand

But see there are numerous ways things might not balanceSlide20

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Better search methods can find the balanceSlide21

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Frequency Adaptive Power Utility Regulator (FAPER): Fast control

The Energy MarketplaceMarketplace Interface to CustomerSlide22

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Market Interface to Customer (MIC)

Need to get ‘price’ or ‘prices’ to Customer

Requirement may be only 5 to 10 minutes

Anticipated that there might need to be a confirming signal in reverse

Automation at the customer premises was anticipated

Some form of ‘smart meter’ was also anticipatedSlide23

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To avoid this fellow (who

Scheweppe

anticipated)

Smart Meter does not report on customers in real time

Measures power, multiplies by price, integrates the result

Market Interface to CustomerSlide24

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Later work at MIT:

‘The Energy Box’

Richard Larson and students:

Dan

Livengood

Woei

Ling

Leow

Anticipates forecasts of price, weather, etc. will be required

This is an image from

Livengood’s

thesis, (taken without permission)Slide25

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Current work: using an office building for ancillary services (Young-Jin Kim)

Solar

Cells

Electric Car Charging

Air Conditioner ModulationSlide26

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Discussion

This work was presented to the IEEE Power Engineering Society Summer Meeting in Vancouver

Charles J. Frank of EPRI told us we were idiots

None of the group had any experience with running a utility

We don’t know what spinning reserve is (misuse the term)

FAPER would cost $60k

Robert W. Alford of Siemens-Allis said that

I

ndirect load control would not be effective

Complicated pricing structures require too much customer participation

Confirmation of prices posted every 5 minutes would require too much

bandwidth

The Electric Utility Business is not as mature

as it used to be.