Energy-Efficient Signal Processing Techniques For Smart Grid Heterogeneous

Communication Networks

Prof. Naofal Al-Dhahir Prof. Brian L. Evans

Univ. of Texas at Dallas Univ. of Texas at Austin

SRC GRC ICSS S7.1 Smart Grid Applications

Task ID: 1836.133

May 7, 2014

Project Kickoff Presentation

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Task Description:Improve rate, reliability, and energy efficiency of two-way wireless and powerline communications (PLC) between smart meters & data concentrators in smart grids

Anticipated Results: Signal processing algorithms and real-time prototypes to demonstrate enhanced performance of wireless and PLC transceivers for smart grids

PI/Co-PI:Prof. N. Al-Dhahir (UT-Dallas) and B. L. Evans (UT-Austin)

Current Students (with expected graduation dates):Ms. Jing Lin Ph.D. (May 2014) Summer 2013 intern at TIMr. Karl Nieman Ph.D. (May 2015) Summer 2013 intern at FreescaleMr. Mostafa Ibrahim Ph.D. (May 2017) Summer 2014 intern at TI

Industrial Liaisons:Dr. Anuj Batra (TI), Dr. Anand Dabak (TI) and Dr. Khurram Waheed (Freescale)

Starting Date:February 1, 2014

Task Summary | Smart Grids | Focus | Tasks | Highlights

SRC GRC Task 1836.133 Al-Dhahir and Evans

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Central power plant

Wind farm

Houses Offices

HV-MV Transformer

Industrial plant

Utility control center

Integrating distributed energy resources

Smart meters

Automated control for smart appliances

Grid status monitoring

Device-specific billing

High Voltage (HV)33 kV – 765 kV

Medium Voltage (MV)1 kV – 33 kV

Smart Grid

Task Summary | Smart Grids | Focus | Tasks | Highlights

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Smart Grid Goals

• Accommodate all generation types

• Improve operating efficienciesScale voltage with energy demand

Bill customer using real-time rates

Reduce peak demand (duty cycling)

Analyze customer load profiles

Analyze system load snapshots

• Improve system reliabilityMonitor power quality

Disconnect/reconnect remotely

Notify outage/restoration event

• Inform customer

Source: Jerry Melcher, IEEE Smart Grid Short Course, 22 Oct. 2011, Austin TX USA

Enabled bytwo-waysmart meter communications

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Task Summary | Smart Grids | Focus | Tasks | Highlights

Project Focus

Focus: neighborhood-area smart utility network between a data concentrator and smart meters along two paths:

1) Low-voltage power lines in 3-500 kHz band

2) Unlicensed 902-928 MHz wireless band

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PLC example: transformer in USAand rare elsewhere

Task Summary | Smart Grids | Focus | Tasks | Highlights

SRC GRC Task 1836.133 Al-Dhahir and Evans

Task Deliverables

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Date Task

June 2015

Algorithms/software for low-complexity interference cancellation methods that exploit channel and interference characteristics to reduce bit error rate by 10x

August 2015

Architecture/algorithm for PLC-wireless diversity combining method with at least 2x improvement in energy efficiency over state of the art

January 2017

Efficient wireless coexistence mechanisms in the unlicensed 902-928 MHz frequency band

January 2017

Demonstrations on UT Austin wireless and PLC testbeds

Task Summary | Smart Grids | Focus | Tasks | Highlights

SRC GRC Task 1836.133 Al-Dhahir and Evans

PLC/Wireless Diversity

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• Simultaneous PLC/wireless transmissions are independent and experience different interference characteristics

• Goal: Improve reliability of smart grid communications using PLC/wireless receive diversity combining methods

Task Summary | Smart Grids | Focus | Tasks | Highlights

SRC GRC Task 1836.133 Al-Dhahir and Evans

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Unlicensed Wireless Comm. vs. PLC SystemsUnlicensed Wireless

CommunicationsNarrowband Powerline

Communications (3-500 kHz)

Power loss vs. distance d

d –n/2

n is propagation constante – a(f) d

plus attenuation from transformers

Propagation Dynamic Static (fixed grid topology)

Additive noise/ interference model

Gaussian noise Gaussian noise +Cyclostationary interference

Asynchronous interference

Uncoordinated users in unlicensed bands using same/other standards

Power electronics and uncoordinated users

using other standards

Multi-Input Multi-Output (MIMO)

Enhance data rate (spatial multiplexing) &

reliability (diversity);Adopted in Wi-Fi and

cellular standards

Enhance data rate through spatial multiplexing (not much diversity);

Adopted in G.9964 standard forin-home broadband PLC

Task Summary | Smart Grids | Focus | Tasks | Highlights

SRC GRC Task 1836.133 Al-Dhahir and Evans

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Wireless Coexistence Mechanisms

• Interference avoidance and/or management• Between IEEE 802.11ah and IEEE 802.15.4g smart utility networks

in the unlicensed 902-928 MHz band

• Receiver-based: channel sensing• Enhanced low-power algorithms that exploit signal waveform

properties

• Transmitter-based: dynamic spectrum management • Adjust transmit power/bandwidth dynamically to reduce mutual

interference• Long successful track record in DSL and other standards

• Goal: Enable coexistence of IEEE 802.11ah and IEEE 802.15.4g smart utility networks

Task Summary | Smart Grids | Focus | Tasks | Highlights

SRC GRC Task 1836.133 Al-Dhahir and Evans

Interference Cancellation

• Interference limits performance• Cyclostationary noise for PLC

• Period is half AC power cycle• Spectrum varies with time• Modeled as Gaussian noise

feeding three different filters

• Asynchronous noise in unlicensed wireless bands• Modeled as Gaussian mixture

• High-complexity receivers reduce bit error rates 10x-100x• Goal: Find low-complexity methods using joint transmitter-

receiver processing with similar reduction in bit error rates

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SRC GRC Task 1836.133 Al-Dhahir and Evans

PLC and Wireless Testbeds

• Three PLC testbeds for earlier SRC GRC Task 1836.063• TI PLC modems controlled by NI hardware/software

• Collected and analyzed field measurements• Demonstrated lack of diversity for transmitting over two phases

• Freescale PLC modems controlled by PC• Collected and analyzed field measurements• Developed bit allocation based on previous estimates of interference

• Xilinx FPGAs controlled by NI hardware/software• Mapped interference cancellation algorithms onto FPGAs in realtime

• Goal: Develop testbeds to evaluate communication performance vs. complexity tradeoffs for the other tasks

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SRC GRC Task 1836.133 Al-Dhahir and Evans

Project Highlights

• PLC-wireless diversity combining task• Completed characterization of wireless link and PLC link• Investigating diversity combining schemes based on both average

and instantaneous SNR measurements

• Low-power interference cancellation task• PLC case: Ms. Lin completed PhD dissertation May 2014: Robust

Transceivers for Combating Impulsive Noise in Powerline Comm.• Plans for investigating wireless case in fall 2014 and spring 2015

• Conference calls: TI (monthly) and Freescale (to start)• Synergistic Activities

• Drs. Al-Dhahir, Batra (TI), Dabak (TI), Evans, Waheed (Freescale) organizing 2015 IEEE International Symposium on Power Line Communications and Its Applications in Austin, Mar. 29-Apr. 1

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SRC GRC Task 1836.133 Al-Dhahir and Evans

Thank you for your attention…

Questions?

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