Complex Power Line Networks: Mobile Machines

Douglas Carter

EtherNetNetwork

EtherNetNetwork

EtherNet link

Wi-Fi link

EtherNetNetwork

MV Cable

EtherNetNetwork

NetworkBridge

NetworkBridge

EtherNet link

Low-voltage PLC

Power Line Modem

PLC over MV

PLC Coupler

PowerCentre

PLCEtherNet

TunnellingMachine

PLCEtherNet

Up to 400 m

Past Present & Future

Bridged Protocol Serial EtherNet

Application Protocols Proprietary Internet: IP, web, etc.Streaming: VoIP, video, etc.Industrial: EtherNet/IP, etc.

Data Rate [bit/s] 10k 100k … 1M … 10M

Network Topology Point-to-point (P2P) P2P, star, mesh

Challenge 1: Complex network requirements

PowerCentre

PLCEtherNet

TunnellingMachine

?

?

Breaker/Feeder

Shuttle Car

PLCEtherNet

• > 2 nodes in the PLC network.

• No more master/slave.

• Nodes must coordinate to prevent collisions.

• Nodes must be addressable.

Adopt power line technology based on IEEE 1901.

PLC over MV

PLCEtherNet PLC

EtherNet

PLCEtherNet

PLCEtherNet

“PL network operates as a standard network switch”

• Inject PLC signal onto power conductors.

• Maintain isolation between LV and MV.

• Inductive

– Simple to install: core clamps over conductor.

• Capacitive

– Connected across two phases.

• Isolated from line voltage

• Available in current rating up to 650A

• Series (inline) injection onto line

• Single inlet to machine

• Current up to 600A

• Multiple outlets, current each 50A to 600A

• Single inlet, current is sum of outlets, > 1500A

• Outlets are supplied from common bus bars

• Where and how to couple?

• Isolated from line current

• Must be rated for line voltage

• Shunt injection between lines

Inductive Coupler

Couplingaffectedby load

here

Unevencoupling

Equalcoupling

Capacitive Coupler

PowerCentre

PLCEtherNet

PLC

TunnellingMachine

EtherNet

Breaker/Feeder

PLCEtherNet

Past Present & Future

Modulation “Traditional” OFDM

Noise immunity Poor to moderate Good

Channel optimisation None to moderate Excellent

Carrier Frequency 100 kHz 10 MHz

Transmission distance Good Moderate

Challenge 2: Maintain transmission distances

0

20

40

60

80

100

0 100 200 300 400 500 600 700

PH

Y D

ata

Rat

e [

Mb

ps]

Cable Length [m]

Reported Operation

up to 600 m

VerifiedOperation

Spitfire performance with capacitive coupler on u/g mining cable

Sub-Station

?

PLCEtherNet

TunnellingMachine

Power CentrePLC

EtherNet

Up to 1000 m

• Transfer over network 1, then over network 2

• Protocol must allow co-existing networks

Length each PLN segment < Max PLC range

Sub-Station

PLCEtherNet

TunnellingMachine

Power Centre

PLC PLC

EtherNet

PLCEtherNet

• Room and pillar tunnelling:

2x continuous miners feeding common conveyor

Operating out of line-of-sight

Affects production efficiency

• Required a signalling system to maintain alternate access to conveyor

PowerCentre

EtherNet

TunnellingMachine B

PLCEtherNet

TunnellingMachine A

PLC

PLC

PLCEtherNet

• Modern underground operations demand:

Higher data rates

Complex network topologies

Increased area coverage

• These can be met by state-of-the-art broadband PLC devices