IED Time Synchronization John Levine, P.E. Levine Lectronics and Lectric

2 MultiSync GPS Clock Why do we need to synchronize our relays? Relays at all three locations tripped. All three had different times. Are these events related???

3 MultiSync GPS Clock Definitions the marking of an event with respect to a reference origin. GPS time signals, based on the atomic clock in GPS satellites, are the reference origin. Time a measurement of duration between events. Time interval a time system adopted in UTC is based on the weighted combination of atomic clocks located around the world. UTC occasionally changes by the addition of leap seconds. Coordinated Universal Time (UTC) High-precision atomic coordinate time standard, basis for UTC. 35 seconds ahead of UTC. International Atomic Time (TAI) the measure of the number of events that occur within a time interval, such as the number of oscillations of a voltage waveform within one second Frequency

4 MultiSync GPS Clock QMI 5/28/2014 GPS GPS Satellite Navigation System uses precise time measurements to measure the distance between a receiver and satellites GPS satellites use atomic clocks for accuracy GPS satellites are the source of timing signals for clock applications ±100 nanosecond accuracy GPS time is not UTC time UTC time adds leap seconds, GPS does not GPS time is 16 seconds ahead of UTC

5 MultiSync GPS Clock QMI 5/28/2014 NTP / SNTP Network time protocol (NTP) networking protocol for clock synchronization between devices operating over packet-switched, variable-latency data networks. Calculates round trip delay Doesn’t accurately cover switch delays, network traffic, reconfigurations Benefits to NTP Uses SCADA Ethernet network Good enough for SOE Detriments to NTP Accuracy in the ms range Not sufficient for synchrophasors

6 MultiSync GPS Clock QMI 5/28/2014 IRIG-B IRIG Formats developed by U.S. Military IRIG-B is 1 specific format used in utility and industrial applications IRIG-B is an analog signal Uses voltage pulses on copper wire Pulses indicate time from fractions of second from midnight, date from January 1st Benefits of IRIG-B Proven Sub- μs accuracy Detriments of IRIG-B Number of devices, distance limited by voltage drop Redundancy difficult Requires careful wiring design Must have an antenna for each clock location

7 MultiSync GPS Clock QMI 5/28/2014 IEEE 1588 IEEE Std IEEE Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems. a.k.a. “PTP” or “Precision Time Protocol” Message based protocol for packet based networks Nano-second accuracy possible Uses TAI time

8 MultiSync GPS Clock Challenges to network time synch Ethernet switches Buffering adds delays Pause frames add delays Multiple master clocks possible Determining the master clock Network segmentation Determining the master clock

9 MultiSync GPS Clock QMI 5/28/2014 How 1588 works (peer-to-peer) C Message based synchronization to measure peer delays Best Master Clock (BMC) algorithm determines the best Master to use BMC runs continuously for network changes Synchronize through message transactions by measuring peer-to- peer delays between devices Each Peer measures delay between devices using Pdelay_Req and Pdelay_Resp Switches measure queuing delay internally Calculations are between devices

10 MultiSync GPS Clock IEEE 1588 architecture (peer-to- peer)

11 MultiSync GPS Clock Modern Time Synchronization by GE Add 1588 capabilities for future expansion while supporting in-service IRIG-B devices

12 MultiSync GPS Clock QMI 5/28/2014 Redundant clocks for reliability All devices have clocks All 1588 clocks run BMC Will choose best clock source based on BMC algorithm, switch configuration Clock in individual devices will choose the second clock if the first clock is unavailable. Redundancy for critical applications like wide area control through synchrophasors, process bus

MultiSync 100 Overview

14 MultiSync GPS Clock QMI 5/28/2014 MultiSync GPS Clock Time synchronization Inputs: GPS antenna (BNC port), 1588 over network (the RJ-45 port) Time synchronization outputs: 1 RJ-45 Ethernet port 1588 and NTP/SNTP simultaneously 1588 or 1588/C TTL ports (BNC connectors) IRIG-B (DC Shift), with IEEE 1344 extensions Multiple other analog time synch profiles

15 MultiSync GPS Clock QMI 5/28/2014 Protocols Supported IRIG-B (Un-modulated, DCLS - C37.118) DC level shift un-modulated IEEE 1344 extension (C37.118) Modified Manchester User defined pulses NTP/ SNTP (IEC 61850) IEEE (Supports Power Profile - C ) DCF77 SNMP v1, v2c & v3

16 MultiSync GPS Clock QMI 5/28/2014 Clock capabilities Time: Support for UTC time, local time settings, DST settings Configurable Alarms

17 MultiSync GPS Clock QMI 5/28/2014 MultiSync 100 hardware Compact size DIN-rail mount Universal power supply (36 – 300V DC) IP30 Ingress IPC 610 Class 3 boards

18 MultiSync GPS Clock QMI 5/28/2014 MultiSync 100 Hardware – cont.

19 MultiSync GPS Clock QMI 5/28/2014 Configured in Software

20 MultiSync GPS Clock QMI 5/28/2014 Security Password protection User authentication Data encryption RBAC User groups

21 MultiSync GPS Clock Where the MultiSync 100 fits