Product Description; Introduction; Overview - GE N60 Instruction Manual

2 PRODUCT DESCRIPTION

2.1 INTRODUCTION

2 PRODUCT DESCRIPTION 2.1INTRODUCTION

2.1.1 OVERVIEW

The N60 Network Stability and Synchrophasor Measurement System is a flexible microprocessor-based device intended
for development of load shedding and special protection schemes.
Owing to its modular architecture, the N60 can be configured to monitor from one through five three-phase power circuits.
The relay provides for variety of metering functions, including: active, reactive and apparent power on a per-phase and
three-phase basis; true RMS value, phasors and symmetrical components of currents and voltages; and power factor and
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frequency. The latter could be measured independently and simultaneously from up to six different signals.
The N60 allows interfacing other analog signals via optional transducer modules to monitor equipment temperature, trans-
former tap positions, weather data, and other information.
In addition to a standard collection of communications protocols that can be exercised simultaneously and independently
over a range of communication ports, including the redundant Ethernet port, the relay supports an independent mechanism
for direct, fast and secure digital inter-IED communications. This allows both reducing wiring and development time for all
the local connections in a substation, as well as building wide-area protection and control schemes.
Up to 64 on/off signals can be exchanged between any two N60 devices via digital communications. The relays could be
configured in rings with up to 16 devices each using direct fiber (C37.94), G.704 and RS422 interfaces. An optional redun-
dant (dual-channel) communication card supports combinations of the three interfaces allowing different physical connec-
tions in each channel. Dual-ring communication architecture could be selected for redundancy. Open ring or crossover
configurations could be utilized to increase the number of devices in the scheme.
The effective message delivery time depends of number of other N60 devices located between the sending and receiving
IEDs. A two-cycle or one-cycle worst-case message delivery times could be comfortably achieved for comparatively large
N60 schemes.
Sophisticated self-monitoring and diagnostic functions are incorporated such as the 32-bit CRC, unreturned messages
count or lost packets counts. The N60 supports both multiplexed and direct fiber (up to 100 km) inter-substation connec-
tions.
The N60 allows sending and receiving any analog value measured by the relay using the dedicated inter-IED communica-
tion mechanisms. Power, voltage and current magnitudes, frequency, transducer inputs and other values can be freely con-
figured for the inter-IED exchanges. The analog values are transmitted with the eight-bit resolution. Upon reception, any
remote analog value could be re-sent, compared with another value or a constant threshold, added to or subtracted from
other local or remote analog value, subjected to the rate-of-change monitoring, etc. This powerful feature allows advanced
applications such as balancing power over wide areas, or adding extra security by comparing local and remote measure-
ments for consistency. It also facilitates simple telemetry.
Diagnostic features include an event recorder capable of storing 1024 time-tagged events, oscillography capable of storing
up to 64 records with programmable trigger, content and sampling rate, and data logger acquisition of up to 16 channels,
with programmable content and sampling rate. The internal clock used for time-tagging can be synchronized with an IRIG-
B signal, using the Simple Network Time Protocol (SNTP) over the Ethernet port, or using the Precision Time Protocol
(PTP). This precise time stamping allows the sequence of events to be determined throughout the system. Events can also
be programmed (via FlexLogic equations) to trigger oscillography data capture which may be set to record the measured
parameters before and after the event for viewing on a personal computer (PC). These tools significantly reduce trouble-
shooting time and simplify report generation in the event of a system fault.
Several options are available for communication. A faceplate RS232 port can be used to connect to a computer for the pro-
gramming of settings and the monitoring of actual values. The RS232 port has a fixed baud rate of 19.2 kbps. The rear
RS485 port allows independent access by operating and engineering staff. It can be connected to system computers with
baud rates up to 115.2 kbps. All serial ports use the Modbus RTU protocol. The IEC 60870-5-103 protocol is supported on
the RS485 interface. IEC 60870-5-103, DNP, and Modbus cannot be enabled simultaneously on this interface. Also only
one of the DNP, IEC 60870-5-103, and IEC 60870-5-104 protocols can be enabled at any time on the relay. When the IEC
60870-5-103 protocol is chosen, the RS485 port has a fixed even parity and the baud rate can be either 9.6 kbps or 19.2
kbps. The 100Base-FX 100Base-T Ethernet interface provides fast, reliable communications in noisy environments. The
Ethernet port supports MMS/UCA2, IEC 61850-90-5, Modbus/TCP, TFTP, and PTP (according to IEEE Std. 1588-2008 or
IEC 61588:2009(E)) protocols, and allows access to the relay via any standard web browser (UR web pages). The IEC
60870-5-104 protocol is supported on the Ethernet port. The Ethernet port also supports the Parallel Redundancy Protocol
(PRP) of IEC 62439-3 (clause 4, 2012) when purchased as an option.
Settings and actual values can be accessed from the front panel or EnerVista software.
GE Multilin N60 Network Stability and Synchrophasor Measurement System 2-1