SEL繼電器SEL-387A特色應用及原理
Current Differential and Overcurrent Relay
The SEL-387A Current Differential and Overcurrent Relay offers restrained and unrestrained differential protection for two terminals. Second-, fourth-, and fifth-harmonic elements, augmented by the dc element, provide security during transformer energization and overexcitation conditions in a user-defined choice of either harmonic restraint or harmonic blocking. Overcurrent elements provide backup protection that contributes to the versatility of the SEL-387A.
sel-387a
電流差動和過流繼電器
sel-387a差動電流和過電流繼電器提供了內斂與奔放兩端差動保護。二-，第四-，和第五次諧波成分，增加了直流分量，提供安全保障，在變壓器通電和過勵磁條件下在一個用戶定義的選擇諧波或諧波閉鎖。過流元件提供備份保護，有助于對sel-387a通用性。
SEL繼電器SEL-387A特色應用及原理
Two-Winding Current Differential Protection
The SEL-387A offers sensitive current differential protection with programmable single- or dual-slope percentage restraint, supervised by a choice of second- and fourth-harmonic blocking or restraint elements, plus fifth-harmonic and dc blocking elements for secure protection of up to two windings. Phase current harmonic blocking is set for either common or independent winding basis. Unrestrained high-set differential elements provide fast operation for high-magnitude internal faults. “Around the clock” phase angle compensation settings and automatic tap calculations simplify settings.
Individual Winding Overcurrent Protection
Torque-controllable overcurrent elements, including one instantaneous, one definite-time, and one inverse-time element each for phase, negative-sequence, and residual ground currents, provide comprehensive overcurrent protection on each winding input.
Through-Fault Recording and Monitoring
Through-fault duty is recorded and accumulated for use in SELogic control equations or manual monitoring.
Protection and Control Logic
Restricted Earth Fault (REF) logic provides sensitive grounded-wye winding ground fault protection. SELogic control equations with SELogic variables, timers, latch bits, and remote control elements are used for customizing advanced protection and control schemes. Local programmable control elements and programmable text display points provide an advanced local operator interface.
Metering and Reporting
Oscillographic event reports (up to seven 60-cycle reports), Sequential Events Recorder (SER) reporting, and accurate metering eliminate or reduce external recorder and metering requirements. Station battery voltage monitor and circuit breaker contact wear monitor provide important data for Reliability Centered Maintenance (RCM) programs. Use with the SEL-2600A RTD Module to meter temperatures from as many as 24 RTDs.
acSELerator QuickSet Software
Develop relay settings offline, program SELogic control equations, and analyze post-fault event reports.
SEL繼電器SEL-387A特色應用及原理
SEL繼電器特色應用
多繞組變壓器電流差動保護與利用相結合的單多達四繞組或雙斜率比率差動特性、過流保護和限制接地故障（REF）保護。是的sel-387a雙繞組變壓器保護的低成本的解決方案。
除了典型的變壓器保護器、發電機、大型電機、等多端電源裝置。提供備用配電母線或饋線保護與低側過電流元件。
個別繞組過電流保護提供了全面的過電流保護，每個繞組輸入轉矩可控的過電流元件。
基于狀態的維修可選的熱監測，以激活一個控制動作或發出報警時，變壓器有過多的絕緣老化或生命損失的危險。通過故障監測收集累積的故障數據，并安排主動維護。