Signal Processing; Ur Signal Processing - GE L30 Instruction Manual

SIGNAL PROCESSING

2
2.5 Signal processing

2.5.1 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
contact 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.
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UR - ** - *
| 7I | 1300 nm, multimode, LED, 2 Channels
| 7J | 1300 nm, single-mode, ELED, 2 Channels
| 7K | 1300 nm, single-mode, Laser, 2 Channels
| 7L | Channel 1 - RS422; Channel 2 - 820 nm, multimode, LED
| 7M | Channel 1 - RS422; Channel 2 - 1300 nm, multimode, LED
| 7N | Channel 1 - RS422; Channel 2 - 1300 nm, single-mode, ELED
| 7P | Channel 1 - RS422; Channel 2 - 1300 nm, single-mode, Laser
| 7Q | Channel 1 - G.703; Channel 2 - 1300 nm, single-mode Laser
| 7R | G.703, 1 Channel
| 7S | G.703, 2 Channels
| 7T | RS422, 1 Channel
| 7W | RS422, 2 Channels
CHAPTER 2: PRODUCT DESCRIPTION
L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL