Agc Structure for Smart Grids

8/12/2019 Agc Structure for Smart Grids

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Why conventional AGC structure fails in a Smart grid

scenario.

Tools which the new AGC structure uses to combat the

challenges.

New AGC structure . ( Control diagram )

Cyber Architecture for the New AGC structure.

Challenges for the new AGC structure.


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Smart power grids have great penetration of Renewable

energy resources in the generation sector.

Although this provides clean energy , brings the sustainability

factor also brings the intermittency factor.

Sudden cloud cover or sudden storms cause sudden drop intheir power generations which are of greater deviation and

more sudden compared to general load variations

The secondary control of the AGC and the supplementary

control have found wanting in these scenarios. ACE is a vital indicative of the power imbalance and value is

used by the new AGC structure to provide effective control.


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ACE of an ISO with a sampling rate of 5s. Rapid ACE changeoccurs during sudden loss of INGs.

A threshold of ACE can be set to detect a ING loss and bringin fast reserves. Conventionally Gas fired units are used forthis.


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Demand Response : Demand response (DR) traditionally

refers to the ability to curtail some electrical load at peak timesto alleviate the need for peaking generation resources .

Good candidates for demand dispatch include dish washers,

washers and dryers, electric hot water heaters, HVAC system

with thermal storage, battery chargers, Plug- in- vehicles andsome aspect of refrigeration operation.

Much of the recent interest in DR, particularly in areas withorganized regional wholesale power market, has focused on

price responsive demand (PRD).

Numerous analysis of customer response to dynamic pricingand DR programs have reported that consumers on averagerespond when facing retail price signals that vary from theirstandard rates.


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Smart meters provide the consumers with their current usage

of electricity and current tariff being applied to their usage.

During peak loads and sudden intermittencies of INGs the

consumers participate in voluntary load shedding or the ISO

can curtail their critical loads with an incentive tariff toappease them.


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Pumped Hydro Energy Storage

Compressed Air Energy Storage

Battery Energy Storage

Superconducting Magnetic Energy Storage (SMES)

Super Capacitor Energy Storage

Fly Wheel Energy Storage

Thermal Energy Storage System

Hydrogen Energy Storage system


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AGC must adopt distinct decision and control strategies to

cope with the low- and high-frequency load fluctuations. By

modeling the load dynamic trends using the one-step-ahead

load model, both high- and low-frequency load fluctuations

can be controlled by judicious selection of AGC assets. The

idea behind this methodology is based on system identificationusing a recursive sample of observations Y(k) and identifying

the underlying process model and its parameters. The load

observed sequence corresponds to stochastic processes and is

produced by an autoregressive moving average (ARMA)model.


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The new AGC structure to overcome the drawback ofintermittency in smart power grids. Also the new AGC has acyber architecture to accommodate intermittency of INGs

One-step-ahead load forecast for valve point control of CPSassets.

Optimal dynamic load control of VPS units to follow a one-step-ahead load target.

The distributed community storage (DCS) together with loaddynamic response (DR) and aggregated DRs as virtual

generator (DR/VG) assets are used to control high-frequencyload fluctuations.

The INGs and nuclear units are used as base loads.


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The research problems are as follows:

i) A cyber-power grid system that can monitor the state of

power grid.

ii) Online gross dynamic models of boilers.

iii) A smart power grid AGC simulator for operator training.


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[1]. Keyhani, A.; Chatterjee, A., "Automatic Generation Control Structure forSmart Power Grids," Smart Grid, IEEE Transactions on, vol.3, no.3,

pp.1310,1316, Sept. 2012.

[2]. K. Moslehi and R. Kumar, Vision of a self-healing power grid, ABBRev., pp. 2125, Apr. 2006.

[3]. Juelsgaard, M.; Totu, L.C.; Shafiei, S.E.; Wisniewski, R.; Stoustrup, J.,"Control structures for Smart Grid balancing," Innovative Smart GridTechnologies Europe 2013 4th IEEE/PES, vol., no., pp.1,5, 6-9 Oct. 2013.

[4]. P. Kundur, Power System Stability and Control. Palo Alto, CA: Mc-Graw-Hill, 1994.

[5]. P. Varaiya, F. Wu, and J. Bialek, Smart operation of smart grid: Risklimiting dispatch, Proceedings of the IEEE, vol. 99, no. 1, 2011.

[6]. D.P. Chassin. How Demand Response can mitigate renewableintermittency Pacific Northwest National laboratory.

[7]. Hatziargyriou, N.; Asano, H.; Iravani, R.; Marnay, C., "Microgrids," Powerand Energy Magazine, IEEE, vol.5, no.4, pp.78, 94, July-Aug. 2007

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Agc Structure for Smart Grids