GE C60 User Manual

GE Multilin C60 Breaker Protection System 2-17
2 PRODUCT DESCRIPTION 2.3 SIGNAL PROCESSING
2
2.3SIGNAL PROCESSING 2.3.1 UR SIGNAL PROCESSING
The UR series relays are microprocessor-based protective relays that are designed to measure power system conditions
directly via CT and PT inputs and via other sources of information, such as analog inputs, communications inputs and con-
tact inputs. The following figure shows the overall signal processing in URs.
An analog low pass anti-aliasing filter with a 3 dB corner frequency is set at 2.4 kHz and is used for current and voltage
analog filtering as well as signal conditioning. The same filtering is applied for phase, ground currents, phase-to-phase
(when applicable), and auxiliary voltages. The 2.4 kHz cut-off frequency applies to both 50 Hz and 60 Hz applications and
fixed in the hardware, and thus is not dependent on the system nominal frequency setting.
Figure 2–3: UR SIGNAL PROCESSING
The UR samples its AC signals at 64 samples per cycle, that is, at 3840 Hz in 60 Hz systems, and 3200 Hz in 50 Hz sys-
tems. The sampling rate is dynamically adjusted to the actual system frequency by an accurate and fast frequency tracking
system.
The A/D converter has the following ranges of AC signals:
Voltages:
(EQ 2.1)
Currents:
From
CT/VT
U
I
Analog Inputs
Analog low-
pass filter
Analog-to-
Digital
Converter
A
Digital band-
pass filter
DSP module
Phasor
estimation
½ cycle
Fourier
1 cycle
Fourier
RMS
values
Fundamen
tal freq.
Phasors,
Seq. com-
ponents
D
Sampling
frequency
CPU module
I>
Z<
U<
Protection
algorithms
IRIG-B
IEEE
1588
SNTP
Tracking
frequency
selection,
estimation
Accurate
Real-Time
clock
Synchrophasors
calculations
Serial
ports
Ethernet
ports
Communi-
cation
protocols
Control
elements,
monitoring
elements,
FlexLogic,
Aggregation,
post-filtering
Contact Inputs
module
HMI
Ddebounce
filtering
Optoisolated
Analog Inputs
module
DCmA, RTD
A
D
Inter-relay
comms
module
Channel
monitoring
CRC check
G.703, RS-422,
C37.94, direct fiber
Contact Outputs
module
Et
h
e
r
n
e
t
Serial
PMU (IEEE C37.118,
IEC 61850-90-5)
IEC 61850 (GOOSE,
MMS Server)
DNP, Modbus,
IEC60870
Comtrade, data
logger
Events
Inter-relay
comms
module
Frequency
T
Analog Outputs
module
Time stamping
Synchro-
phasors
filtering
859740A1.vsd
2± 260 V()⋅

GE C60 Specifications

General

Brand	GE
Model	C60
Category	Relays
Language	English