SEL-487E-3, -4 Transformer Differential Relay
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SEL-487E-3, -4 Transformer Differential Relay Three-Phase Transformer Protection, Automation, and Control System Major Features and Benefits The SEL-487E Transformer Differential Relay provides three-phase differential protection for transformer applications with as many as five three-phase restraint current inputs. Use the three independent restricted earth fault (REF) elements for sensitive ground-fault detection in grounded wye-transformer applications. Detect turn-to-turn winding faults for as little as two percent of the total transformer winding with the negative-sequence differential element. Apply the two three-phase voltage inputs for over- and undervoltage, frequency, and volts/hertz protection. Make any overcurrent element directional using voltage polarized directional elements as torque control inputs to the overcurrent elements. Monitor and protect critical substation assets with comprehensive breaker wear and transformer thermal and through-fault monitoring. Perform bay control functions for as many as five breakers and 20 disconnect switches using the built-in system mimic diagrams. Schweitzer Engineering Laboratories, Inc.

High-Speed Differential Protection. A two-stage slope adapts automatically to external fault conditions, providing fast, sensitive, dependable, and secure differential protection, even for CT saturation and heavily distorted waveforms. Multiple Synchrophasor Data Channels. System-wide monitoring is available through as many as 24 synchrophasor data channels. Record and store up to 120 seconds of IEEE C37.118 binary synchrophasor data. Restricted Earth Fault Protection. Three independent REF elements provide sensitive protection for faults close to the winding neutral in grounded...

► Time-Domain Link (TiDL) Technology. The relay supports remote data acquisition through use of the SEL-2240 Axion®. The Axion provides remote analog and digital data over an IEC 61158 EtherCAT® TiDL network. This technology provides very low and deterministic latency over a fiber point-to-point architecture. The SEL-487E-3, -4 relay can receive fiber links from as many as eight Axion remote data acquisition nodes. Functional Overview 1 Copper or Fiber Optic * Optional Feature Figure 1 Functional Diagram Schweitzer Engineering Laboratories, Inc.

SEL-487E Relay Functions ► SEL-487E three-phase differential protection sensing: ^ 15 restraint input current channels ^ Three REF input current channels ^ Six voltage channels with over- and undervoltage and frequency protection. Voltage inputs accept delta- or wye-connected potential transformers. ► Negative-sequence differential element for sensitive internal fault (turn-to-turn) detection detects as little as two percent short-circuit of total winding ► Five unique IEEE C37.118 compliant synchrophasor data streams via serial or Ethernet communications ports ► Transformer through-fault...

High Voltage Transformer Differential Zone Tertiary Voltage Two-Winding Transformer Application Use the negative-sequence differential element for sensitive detection of interturn faults within the transformer winding. Phase, negative-, and zero-sequence overcurrent elements provide backup protection. Use breaker failure protection with subsidence detection to detect breaker failure and minimize system coordination times. When voltage inputs are provided to the SEL-487E, voltage-based protection elements and frequency tracking are made available. Frequency tracking from 40.0 to 65.0 Hz...

measurement unit in any substation or power generation facility. The SEL-487E can be configured to send five unique synchrophasor data streams over serial and Ethernet ports. Measure voltage and current phase angle relationships at generators and transformers, key source nodes for stability studies and load angle measurements. Use the SEL-487E to store up to 120 seconds of IEEE C37.118 binary synchrophasor data for all 24 analog channels at a recording rate of 60 messages per second. A SELOGIC control equation triggers storage of data. Capture data as necessary, and then store this...

The differential element includes one harmonic blocking and one harmonic restraint element; select either one or both of them. The combination of harmonic blocking and restraint elements provides optimum operating speed and security during inrush conditions. Wave-shape-based inrush detection addresses inrush conditions that contain low second and fourth harmonic content. Fast sub-cycle external fault detection supervision adds security during external faults with CT saturation. The harmonic blocking element includes common or independent 2nd and 4th harmonic blocking and independent...

Adaptive Time-Overcurrent Elements (51S) The relay supports ten adaptive time-overcurrent elements with selectable operate quantity and programmable time-delay and pickup levels. Choose from the ten time-overcurrent curves shown in Table 2 (5 IEC and 5 U.S.). Each torque-controlled time-overcurrent element has two reset characteristics. One choice resets the elements if current drops below pickup for one cycle while the other choice emulates the reset characteristic of an electromechanical induction disk relay. Table 2 Supported Time-Overcurrent Curves The adaptive time-overcurrent elements...

Synchronism Check Synchronism-check elements prevent circuit breakers from closing if the corresponding phases across the open circuit breaker are excessively out of phase, magnitude, or frequency. The SEL-487E synchronism-check elements selectively close circuit breaker poles under the following criteria: ➤ The systems on both sides of the open circuit breaker are in phase (within a settable voltage angle difference). ➤ The voltages on both sides of the open circuit breaker are healthy (within a settable voltage magnitude window). The synchronism-check function is available for as many as...

An ORDER setting is provided to prioritize the selection of zero- or negative-sequence polarization for directional control of ground overcurrent elements using patented Best Choice Ground Directional Element switching logic. Positive- and negative-sequence voltages are used for directional control of phase-overcurrent elements. Positive-sequence voltage memory is used to provide security during three-phase faults. Loss-of-potential elements supervise the voltage-polarized directional elements. Current Unbalance Elements The current unbalance logic uses the average terminal current to...