Deterministic Communications for Protection Applications Over Packet-Based Wide-Area Networks

Transcription

1 Deterministic Communications for Protection Applications Over Packet-Based Wide-Area Networks Kenneth Fodero, Christopher Huntley, and Paul Robertson Schweitzer Engineering Laboratories, Inc SEL

2 How to Preserve Protection Channel Performance in Changing Network Model Many utilities are moving toward converged IT / OT networks IT solutions are being pushed into OT systems Network visibility and management are moving toward centralized model

3 Segregated vs. Integrated OT / IT Model Wind Generation Hydroelectric Generation Corporate Offices Distribution Substation Control Center OT Network IT Network Transmission Substation Solar Generation Fossil Fuel Generation Corporate Offices Segregated Network

4 Segregated vs. Integrated OT / IT Model Wind Generation Hydroelectric Generation Corporate Offices Distribution Substation Control Center OT / IT Network IT Network Transmission Substation Solar Generation Fossil Fuel Generation Integrated Network Corporate Offices

5 Communications-Assisted Protection Minimizes Fault-Clearing Times Enables high-speed tripping Provides coordination Enables differential comparison F1 F2 Relay Communications Channel Relay

6 Communications Channel Failure Negatively Affects Protection Dependability Increased tripping times Longer fault current duration Reduced equipment life Greater risk to safety

7 Protection Performance Requirements for Critical Circuits Scheme Latency (ms) Asymmetry (ms) Restoration (ms) Line current differential (87L) Pilot protection Direct transfer trip (DTT) 5 <

8 Preserving Deterministic Time-Division Multiplexing (TDM) Performance Over Packet Transport Virtual Synchronous Network (VSN) SONET Ethernet TDM Engine Ethernet Engine

9 Achieving Deterministic Packet Transport Deterministic Packet Transport Left Protected Line Module (PLM) Ethertype Handler Right PLM Ethertype Handler Deterministic Packet Transport Packetizer Packetizer TDM Transport TDM Engine TDM Engine TDM Transport TDM Circuits or Critical Ethernet

10 VSN Tunnel Across Core Transport Single provisioned path through core for all protection circuits Core Network

11 Bridging the Technology Gap Core Core Network Network SONET

12 Third-Party Validation of VSN

13 VSN Over Carrier Ethernet and Multiprotocol Label Switching (MPLS) Core Network Three-Node Core Network Ring Traffic Generator Relay Core Node A Core Node C Relay Core Network Core Node B

14 Third-Party Testing Results VSN Over Carrier Ethernet and MPLS Core Network 87L Channel Measurements Carrier Ethernet (ms) MPLS (ms) Round-trip delay Transmit delay Receive delay Asymmetry

15 Core Network Failover Carrier Ethernet and MPLS Core Network Relay Line-current differential Core Node A X Core Node C Relay Line-current differential Core Network Core Node B

16 Edge Network Failover Carrier Ethernet and MPLS Core Network Line-current differential X Relay Core Node A Core Node C Relay Core Network Line-current differential Core Node B

17 Third-Party Testing Results Network Failover and Network Healing Times Core Network Failover Carrier Ethernet MPLS ~20 ms ~50 ms Edge Network Failover VSN 5 ms

18 Required Committed Information Rates (CIRs) STS-n (user-selectable) Core Network CIR (Mbps) STS-1 FE 75 STS-1 94 STS STS STS STS STS STS STS STS STS STS STS

19 VSN Is More Bandwidth-Efficient Network Technology MPLS Bandwidth Efficiency (network-wide) 60 IEEE C37.94 circuits = 120 Mbps Quality of Service (QoS) Management Per circuit VSN 672 IEEE C37.94 circuits = 94 Mbps 1 setting

20 Core Network Quality of Service (QoS) Settings Priority Queue Service 1 Network management 2 VSN 3+ All others

21 Deliver TDM Performance Over Ethernet Packet Core Network Set VSN as next highest priority after network management system (NMS) software Use strict priority scheduling for VSN Provide fixed path through packet core network Perform healing using network edge devices

22 Many Utilities Use Leased Ethernet Services for Substation Communications Substation Leased Ethernet Services Substation / Control Center Utility Analog Circuit Channel Bank 4-Wire VF Circuit T1 Circuit Channel Bank Utility Analog Circuit Analog leased services end by 2020 Migration from analog to Ethernet service Cost and latency performance challenges

23 Solution for Leased Analog Replacement 2-Wire FXO / FXS 4-Wire Analog DTT Leased Ethernet Services 2-Wire FXO / FXS 4-Wire Analog DTT Has equivalent performance to analog circuit (<5 ms latency for contact transfer) Minimizes migration cost

24 VSN Preserves Protection Channel Performance Over Ethernet Packet Core Network

25 Questions?