SEL-387E Current Differential and Voltage Protection Relay
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SEL-387E Current Differential and Voltage Protection Relay Versatile Solution for Power Apparatus Protection Major Features and Benefits The SEL-387E Relay includes three-phase voltage inputs for metering, overexcitation, frequency, and overand undervoltage functions. The three winding current differential elements use second-, fourth-, and fifthharmonic elements, augmented by the dc element, to provide security during transformer energization and overexcitation conditions in a user-defined choice of either harmonic restraint or harmonic blocking. Overcurrent elements, over- and underfrequency elements, over- and undervoltage elements, power and energy metering, and overexcitation protection all contribute to relay versatility. Oscillographic event reports, Sequential Events Recorder (SER), circuit breaker contact wear monitor, and substation battery monitor are all standard features. Four communications ports, local display panel, and extensive automation features are also standard. Expanded I/O is available as an option. ➤ Protection. Protect transformers, buses, generators, reactors, and other apparatus with a combination of differential, overcurrent, and volts/hertz protection. The differential element is set with either a single- or dual-slope percentage differential characteristic for increased security during through-fault conditions. ➤ Metering. Interrogate the relay for instantaneous measurements of voltage, current, MW, MVAR, MVA, MWh, MVARh, demand current, and three-phase demand power. The recorded peak demand, including the date and time of occurrence, is provided. ➤ Monitoring. Schedule breaker maintenance when the breaker monitor indicates. Notify personnel of substation battery voltage problems. Use the SEL-387E through-fault event monitor for information on system through faults and resulting cumulative I2t wear on transformer banks. Monitor critical operating temperatures through use of the SEL-2600A RTD module. ➤ Automation. Take advantage of automation features that include 16 elements for each of the following: local control and local indication with front-panel LCD and pushbuttons, remote control, and latch control. Use the serial communications ports for efficient transmission of such key information as metering data, protection elements and contact I/O status, SER reports, breaker contact wear monitor, relay summary event reports, and time synchronization. Select optional DNP3 Level 2 Slave protocol Schweitzer Engineering Laboratories, Inc.

with virtual terminal support for SCADA system interface capability. Equip the SEL-387E with optional dual fail-over Ethernet communications for Telnet, FTP, read-only web server, and IEC 61850 communications support. ➤ Relay and Logic Settings Software. ACSELERATOR QuickSet® SEL-5030 Software reduces engineering costs for relay settings and logic programming. The built-in HMI provides phasor diagrams that help support commissioning and troubleshooting. Combined Time Overcurrent Phase Ground Overcurrent Time Overcurrent Phase Phase Ground Ground Neg. Seq. Neg. Seq. SELOGIC® Control...

Current Differential Elements The SEL-387E has three differential elements. These elements use operate and restraint quantities calculated from the two- or three-winding input currents. Set the differential elements with either single- or dual-slope percentage differential characteristics. Figure 2 illustrates a dual-slope setting. The percent-slope characteristic helps prevent undesired relay operation because of possible imbalance between CTs during external faults. CT imbalance can result from tap changing in the power transformer and error difference between the CTs on either side of a...

Phase overvoltage elements operate with the maximum of the measured phase voltage magnitudes. Residual overvoltage elements operate with the vectorial sum of three-phase voltage measurements. The positive- and negative-sequence overvoltage elements operate when respective measurements exceed set thresholds. The phase-to-phase overvoltage element operates when maximum phase-to-phase voltage exceeds the set threshold. nents, which can result in overheating. In the SEL-387E, a volts/hertz element detects overexcitation. The SEL-387E provides a sensitive definite-time delayed element, plus a...

Table 2 Metering Capabilities (Sheet 2 of 2) Event Reporting and Sequential Events Recorder (SER) Event report and SER features simplify post-fault analysis and improve understanding of simple and complex protective scheme operations. These features also aid in testing and troubleshooting relay settings and protection schemes. Event Reports In response to a user-selected trigger, the voltage, current, and element status information contained in each event report confirms relay, scheme, and system performance for every fault. Decide how much detail you need when requesting an event report:...

The SEL-387E measures and reports the substation battery voltage at the relay power supply terminals. The relay includes four programmable threshold comparators and associated logic for alarm and control. For example, if the battery charger fails and the measured dc voltage falls below a programmable threshold, operations personnel receive notice before the substation battery voltage falls to unacceptable levels. Monitor these thresholds with an SEL communications processor and trigger messages, telephone calls, or other actions. Obtain a report of the measured dc voltage in the METER...

The ACSELERATOR QuickSet software uses the Microsoft® Windows® operating system to simplify settings and provide analysis support. One can, for instance, open an ACSELERATOR QuickSet human machine interface (HMI) screen and obtain phasor information such as that shown in Figure 5. yjAcSELeratortS. C:\Program Files\Ac5ELerator\LEGACY TEST.rdb [Device ID: STATION Aj File Settings Analysis HMI Communication Window Help © Device Overview • Phasors 1 © Phasors 2 © Instantaneous © D ifferential I nstantaneous G D emand O Energy Metering O T argets O Status O SER 0 Breaker Monitor Data 0 Control...