Power Line Communication from Home Automation to Solar Farm - - PowerPoint PPT Presentation

Power Line Communication from Home Automation to Solar Farm Monitoring

Ekachai Leelarasmee Chulalongkorn University, Bangkok Thailand

funded by Ratchadaphiseksomphot Endowment Fund

• f Chulalongkorn University (RES560530056-EN)

Power Line Communication (PLC)

• Since 1988
• Utilize existing AC power lines to carry

high freq data signal

• Data rate from 1Kbps – 200Mbps

www.prime-alliance.org

230KVac 23KVac 220Vac

PLC signal on AC 220V

622V 80kHz 0.4V

PLC

PLM PLM PLM

Device Device

Voltage (Parallel) Mode PLC

Device Device = Appliance, Computer, ADSL, etc

AC line data

PLM = Power Line communication Module

PLM 80-90kHz

64Kbps, OFDM

10μF 100Ω 15nF 470μH 470nF . 6 8μH : 10 1 Tx Rx

ac

220V Filter Data DSP

Type Narrow Band Broad Band

• Freq. 3-500kHz

2-25MHz Data 2-128Kbps 10-200Mbps Range > km < 300m Uses Monitor/Control High Speed Data STD PRIME,G3,X10 Home Plug Av App Smart Grid Home Network

PLC classification

www.sentec.com

Home Automation (narrow band < 500kHz)

X10, LonTalk Low speed <128kbps Control & Monitor

www.aztech.com

internet

Home Area Network Broadband <25MHz

Home Plug Home Plug AV High speed<200Mbps

www.smartlighting.com

Street Lighting

Lamp maintenance & dimming

Long range

EV Charging station

www.greenvity.com

Smart Grid

MDM OM DSM etc

Narrow band, Long range PRIME, G3

Problems with PLC

1) Noises 1.1) Motor & Switch (intermittent) 1.2) Switching Power Supply (Periodic impulse) 2) Unknown Topology 2.1) Line characteristic varies 2.2) Frequency & Time dependent 2.3) Multiple reflection (coupling loss)

Smart Grid Technology

low data rate (32kbps), real time, long range

PoweRline Intelligent Metering Evolution

Open International PLC Standard for Advance Metering, Grid Control and Asset Monitoring applications 2,500,000 meters deployed worldwide

PRIME TreeTopology

BN: Base Node (DCU) SW: Switch Node (Meter) SN: Service Node (Meter)

Smart Meter

PLC (PRIME) RF (Zigbee) 220V AC in 220V AC out

RF, Optic

Advance Metering Infrastructure (AMI)

Corporate Utility Network Data Concentrature (BN) PLC SN SW SW SN SN Internet

PRIME Protocol Layer

41.992KHz – 88.867KHz 128Kb/Sec OFDM

PRIME OFDM

PRIME MAC Frame Structure

Solar Farm Monitor

8MW 86668 PV panels: fixed topology

+ - 20-100V 50-200W

World Bank 2012 Renew energy projects

Global (MW) Thailand (MW) Bio 1277 39 Hydro 31060 0 Wind 28900 127 Solar 7695 326

Blackout 22 May 2013 Lightning strike

• n 500KV

Not enough local Power generation

Multi-String Topology

PV’s are not identical but must operate at the same current un-optimal

8 20 PVs −

AC

8 20 PVs −

AC AC DC DC

Inverter

I I

1

P

n

P

Mismatched PV panels

defect, cloud, trees, airplane, direction crack, dust, leaves, aging, temperature

P1 + P2 < P1m + P2m 20% loss

P1 P2 I

P1m P2m

weak I P1 P2

Effect of Mismatched PVs

I

Solar Farm (Health) Monitoring

MU CU MU MU MU DCU DC DC AC AC Control center CU CU CU DCU

MU : Monitor Unit (V,I,Temp) CU : Communication Unit DCU: Data Concentrator Unit

RF 433MHz or 2.4GHz

Expensive, Fragile & Complicate

MU MU MU MU CU CU CU CU DCU DCU Control center DC DC AC AC

Serial Mode PLC

MU CU MU MU MU DCU DC DC AC AC CU CU CU DCU

AC Current Mode PLC (analog tech)

Low cost: uses current transformer for coupling high frequency current signal

MU MU MU MU CU CU CU CU DCU DCU DC DC AC AC Control Center

Pulse PLC (digital tech)

Low cost. Toggle switch to transmit data

MU MU MU MU CU CU CU CU DCU DCU DC DC AC AC Control Center

MU MU Tx Rx Rx

ac

I

Superimpose AC Current onto DC Current

1) AC Current Mode PLC

• PV & INV must be short circuit

at carrier frequency ω Tx

i

V

ac

I

Rx

• V
• I

i

I

• Z = ∞

i

Z =

PLC Current Coupling Circuit

m k

L ,L

i

V

• V

2

C

1

C

1

L

ac

I

ac

I

Tx Mode

• 1

m 2

1 ω (L L )C =

• Z

to couple current = ∞

2

• 1

m k 2

1 ω (L (L L ))C = +

• k

L

i

V

2

C

1

L

ac

I

ac

I

m

L Ideal

• Z

2

C

1

L

ac

I

ac

I

m

L Ideal

i 2 i

I jωC V =

• Z

Rx Mode

ac 2

• i
• 1

1 1 1

jI C 1 ω ; V V ω C C L C − = = =

i

Z 0 to avoid loading DC line =

2 2

• k

2

• 2

1 k 1

• 1

k 2

1 ω L C 1 ω (L L )C 1 ω (L L )C − =

• +

−

• m

L

• V

2

C

1

C

1

L

ac

I

ac

I Ideal

k

L

i

Z

m

L

• V

2

C

1

C

1

L

ac

I

ac

I Ideal

i

Z

50W Amorphous PV panels

3Ω 250kHz

Carrier frequency

PV

Z

• ω

0.81A 980 2.2 0.8μ

pv

Z

m k s L

L 84μ L 36μ R 50 R 10k = = = =

m k

L ,L

i

V

• V

2

C

1

C

1

L

ac

I

ac

I

= = = = = = = =

1 1 2 s L i ac ac ac

L 220μH ; C 5.22nF C 1.39nF; R 50 R 10K ; V 1V ; I 2.18mA Energy loss per PV 14μW

Test Experiment for simulation

MU MU CU CU DCU #1 #8

3Ω 3Ω

Monte Carlo Simulation

50 simulations, 20% over 3 sigma Gaussian Distribution

• i

V V

Amplitude Shift Keying (ASK) Data Rate = 25kbit/sec

40μS 40μS 40μS 40μS

1 1 1

4μS 250kHz

MU & CU Circuit

Consume 50uA (2.5mW) while idle

CU MCU

• D

i

D ADC

i

V

• V

1 MΩ 10kΩ

50V + −

3V REG GND

Low Power MU & CU Circuit

M1 is on to wake up MCU MCU turns on/off M2 to keep power on/off to save power

CU MCU

• D

i

D ADC

i

V

• V

50V + −

to ADC M1 M2 3V Gnd M1 M1

• n
• n

Low Power Communication Protocol

CU DCU wake (111) addr & instr ack response sleep

MU MU CU CU DCU DC AC

Pulse PLC

A switch closes temporarily to create a pulse that propagates through the DC Power Line.

D

V (n 1)V if one PV switch closes V 0 for all PV if DCU switch closes = − = Thus DCU can broadcast data to all PVs PV can reply to DCU only

MU

#1 #n V

MU CU CU DCU DC AC

V

D

V

Ideal Waveforms: 8 x (50V) PV

DCU

V

pv

V PV DCU → DCU PV → 400V

300μ 600μ 1 8μ 50V

Pulse shaping due to PV Capacitor

pv ph

C 65nF V 50V I 0.015 0.5A = = = →

r r

T 6.5 220μS Data Rate 1 < 8μ T 4.4kpulse / s = → + =

MU

+ − pv pv r ph

C V T I = V Close V

pv

C

ph

I

PV 8μS Open DC Line Close

AC DC

Transmission Line μ L 1.475 H / m, C 11.3pF / m = =

DCU

V

+

−

Ringing due to transmission line effect

cause ringing

Ringing through DC Line

15m cable 35m cable 1.8MHz close

R 10; L= ; C =

Ringing Suppression at DCU

Y

• Y

R 410Ω to match Z C 2nF to block DC = =

• Z

DCU

V

+

−

Y

R

Y

C

Ringing Suppression at the Switch

pv

V

+ −

pv

V + −

pv

V

C R

Hard Switch

pv

V

Soft Switch

50W Amorphous PV panels

DCU

V

a) Hard Switch (IRFS630) b) Terminate DCU with 410 + 2.2nF c) Soft Switch with 1.5K & 150pF d) Soft Switch under weak sunlight

Negative edge detector

Q is OFF when idle (zero power) ON when there is a neg. pulse

1

C

2

C

2

R

1

R 3V

PV

V DC line PV panel μC

/ ON OFF Switch

p

T Q

P

T

in

• ut

1 P PV 1 2

∆ ; C C ∆ C = +

2 1 2 P

R ∆ ∆ 0.7 R R ≈ ≤ +

( )

2 2 1 P 2

(R R )(C C )ln T ∆ / 0.7 = + +

Design Eq.

1

C

2

C

2

R

1

R

p

T Q ΔPV ΔP Δ

3

3V

3

3V

1 2 1 2 PV P P

R R 10KΩ; C 470pF; C 4.7nF; ∆ 80V ∆ 7.27V T 170μ ; ∆ 3.6 S 3V; = = = = = = = =

Experimental Result

Strong Weak Broadcast by DCU One MU responses

Edge Detector with Regulator

1

C

2

C

2

R

1

R 3V 40V DC line PV panel MCU Q

Edge Detector with Regulator

1

C

2

C

2

R

1

R 3V 40V DC line PV panel MCU Q 3V

MCU Self Bias

P 3 DC

T is long to allow MCU to turn on Q and keep V supply to MCU MCU turns off S to shut down (All transistors OFF)

1

C

2

C

2

R

1

R

PV

V

2

R

1

R MCU

p

T

p

T 3V 3V C

DC

V

1

Q

2

Q

3

Q

P1 + P2 < P1m + P2m 20% loss

P1 P2 I

P1m P2m

weak I P1 P2

Effect of Mismatched PVs

Future Work: Integrated Converter

DC/DC maximizes energy a) from PV. b) to DC/AC. Communication Unit (CU) shares information.

Central control DC/DC DC AC MU/CU DC/DC MU/CU

Advantages of using PLC for solar farm

1) No extra wire 2) Simple Circuits low cost 3) Low power 4) Fixed topology 5) Low noise 6) Low power protocol

Thank You

This research is supported by Ratchadaphiseksomphot Endowment Fund

• f Chulalongkorn University

(RES560530056-EN).