Doni Zhang — Engineering & AI

一、保护基础 | Protection Fundamentals

继电保护— protective relaying —/prəˈtɛktɪv ˈrileɪɪŋ/

保护继电器— protective relay —/prəˈtɛktɪv ˈriˌleɪ/

微机保护— numerical relay; microprocessor-based relay —/nuˈmɛrɪkəl ˈriˌleɪ/

保护方案— protection scheme —/prəˈtɛkʃən skim/

主保护— primary protection; main protection —/ˈpraɪˌmɛri prəˈtɛkʃən/

后备保护— backup protection —/ˈbækˌʌp prəˈtɛkʃən/

远后备— remote backup —/rɪˈmoʊt ˈbækˌʌp/

近后备— local backup —/ˈloʊkəl ˈbækˌʌp/

保护分区— protection zone —/prəˈtɛkʃən zoʊn/

重叠保护— overlapping protection —/ˌoʊvərˈlæpɪŋ prəˈtɛkʃən/

死区— blind spot; dead zone —/blaɪnd spɑt/; /dɛd zoʊn/

选择性— selectivity —/ˌsɛlɛkˈtɪvəti/

速动性— speed; operating time —/spid/; /ˈɑpəˌreɪtɪŋ taɪm/

灵敏性— sensitivity —/ˌsɛnsɪˈtɪvəti/

可靠性— reliability; dependability —/rɪˌlaɪəˈbɪləti/; /dɪˌpɛndəˈbɪləti/

安全性（不误动）— security —/sɪˈkjʊrəti/

二、保护功能类型 | Protection Functions

过电流保护— overcurrent protection (50/51) —/ˌoʊvərˈkɜrənt prəˈtɛkʃən/

定时限过流— definite-time overcurrent —/ˈdɛfɪnɪt taɪm ˌoʊvərˈkɜrənt/

反时限过流— inverse-time overcurrent —/ɪnˈvɜrs taɪm ˌoʊvərˈkɜrənt/

速断保护— instantaneous overcurrent (50) —/ˌɪnstənˈteɪniəs ˌoʊvərˈkɜrənt/

差动保护— differential protection (87) —/ˌdɪfəˈrɛnʃəl prəˈtɛkʃən/

变压器差动— transformer differential —/trænsˈfɔrmər ˌdɪfəˈrɛnʃəl/

母线差动— bus differential —/bʌs ˌdɪfəˈrɛnʃəl/

线路差动— line differential —/laɪn ˌdɪfəˈrɛnʃəl/

距离保护— distance protection (21) —/ˈdɪstəns prəˈtɛkʃən/

过电压保护— overvoltage protection (59) —/ˌoʊvərˈvoʊltɪdʒ prəˈtɛkʃən/

欠电压保护— undervoltage protection (27) —/ˌʌndərˈvoʊltɪdʒ prəˈtɛkʃən/

频率保护— frequency protection (81) —/ˈfrikwənsi prəˈtɛkʃən/

低频减载— under-frequency load shedding —/ˈʌndər ˈfrikwənsi loʊd ˈʃɛdɪŋ/

方向过流— directional overcurrent (67) —/dɪˈrɛkʃənəl ˌoʊvərˈkɜrənt/

零序保护— zero-sequence protection; ground fault protection —/ˈziroʊ ˈsikwəns prəˈtɛkʃən/

负序保护— negative-sequence protection (46) —/ˈnɛɡətɪv ˈsikwəns prəˈtɛkʃən/

断路器失灵保护— breaker failure protection (50BF) —/ˈbreɪkər ˈfeɪljər prəˈtɛkʃən/

三、保护整定 | Protection Settings

整定计算— setting calculation; coordination study —/ˈsɛtɪŋ ˌkælkjəˈleɪʃən/

整定值— setting; pick-up value —/ˈsɛtɪŋ/; /ˈpɪk ʌp ˈvælju/

动作值— operating value; pick-up —/ˈɑpəˌreɪtɪŋ ˈvælju/

返回系数— reset ratio; drop-off ratio —/riˈsɛt ˈreɪʃoʊ/

时间整定— time dial; time multiplier —/taɪm ˈdaɪəl/

时间配合— time coordination; grading —/taɪm koʊˌɔrdɪˈneɪʃən/; /ˈɡreɪdɪŋ/

TCC曲线— TCC (Time-Current Characteristic) curve —/ˈti ˈsi ˈsi kɜrv/

短路计算— short-circuit study —/ʃɔrt ˈsɜrkɪt ˈstʌdi/

最大运行方式— maximum fault condition —/ˈmæksɪməm fɔlt kənˈdɪʃən/

最小运行方式— minimum fault condition —/ˈmɪnɪməm fɔlt kənˈdɪʃən/

CT饱和— CT saturation —/ˈsi ˈti ˌsætʃəˈreɪʃən/

启动值— threshold; start value —/ˈθrɛʃˌhoʊld/

四、控制系统 | Control Systems

控制系统— control system —/kənˈtroʊl ˈsɪstəm/

SCADA系统— SCADA (Supervisory Control and Data Acquisition) —/ˈskeɪdə/

控制回路— control circuit —/kənˈtroʊl ˈsɜrkɪt/

合闸回路— close circuit —/kloʊz ˈsɜrkɪt/

分闸回路— trip circuit —/trɪp ˈsɜrkɪt/

跳闸线圈— trip coil —/trɪp kɔɪl/

合闸线圈— close coil —/kloʊz kɔɪl/

防跳回路— anti-pump circuit —/ˈænti pʌmp ˈsɜrkɪt/

联锁— interlock —/ˈɪntərˌlɑk/

电气闭锁— electrical interlock —/ɪˈlɛktrɪkəl ˈɪntərˌlɑk/

机械闭锁— mechanical interlock —/mɪˈkænɪkəl ˈɪntərˌlɑk/

远方/就地— remote/local —/rɪˈmoʊt/; /ˈloʊkəl/

控制开关— control switch —/kənˈtroʊl swɪtʃ/

指示灯— indicator light; pilot lamp —/ˈɪndɪˌkeɪtər laɪt/; /ˈpaɪlət læmp/

报警— alarm; annunciation —/əˈlɑrm/; /əˌnʌnsiˈeɪʃən/

事件记录— event log; SOE (Sequence of Events) —/ɪˈvɛnt lɔɡ/; /ˈɛs ˈoʊ ˈi/

五、光伏电站保护 | Solar PV Plant Protection

孤岛保护— anti-islanding protection —/ˈænti ˈaɪləndɪŋ prəˈtɛkʃən/

反孤岛— anti-islanding —/ˈænti ˈaɪləndɪŋ/

低电压穿越— LVRT (Low Voltage Ride-Through) —/ˈɛl ˈvi ˈɑr ˈti/

高电压穿越— HVRT (High Voltage Ride-Through) —/ˈeɪtʃ ˈvi ˈɑr ˈti/

频率穿越— frequency ride-through (FRT) —/ˈfrikwənsi raɪd θru/

逆变器保护— inverter protection —/ɪnˈvɜrtər prəˈtɛkʃən/

直流接地故障— DC ground fault —/ˈdi ˈsi ɡraʊnd fɔlt/

极性反接保护— reverse polarity protection —/rɪˈvɜrs pəˈlærəti prəˈtɛkʃən/

电弧故障检测— arc fault detection (AFCI) —/ɑrk fɔlt dɪˈtɛkʃən/

光伏快速关断— rapid shutdown (PVRSS) —/ˈræpɪd ˈʃʌtˌdaʊn/

电网保护继电器— grid protection relay —/ɡrɪd prəˈtɛkʃən ˈriˌleɪ/

并网同步— grid synchronization —/ɡrɪd ˌsɪŋkrənɪˈzeɪʃən/

Protection Coordination — Settings and TCC Curves

Alan

Jiang, let's review the protection coordination for the solar farm. I want to see how you've coordinated the feeder relays with the main transformer and the grid interconnection.

江工，我们过一下光伏电站的保护配合。我想看馈线保护与主变压器和电网互联是怎么配合的。

Alan

江工: Sure. Let me pull up the TCC curves. We have three levels of overcurrent protection: the feeder breakers on the 34.5 kV collector system, the main transformer secondary breaker, and the grid interconnection breaker at 230 kV.

好的。我调出TCC曲线。我们有三层过流保护：34.5 kV集电线路的馈线断路器、主变压器二次侧断路器和230 kV电网互联断路器。

Alan

馈线保护用51反时限过流——极反时限曲线IEEE C3。启动值设为1.2倍满负荷电流、约600A一次侧。时间倍率为0.3。这意味着在5倍启动值时——也就是 3000A——约0.5秒跳闸。

The feeder protection uses 51 inverse-time overcurrent — an extremely inverse curve per IEEE C3. Pick-up is set at 1.2× full load current, about 600A primary. Time dial is 0.3. That means at 5× pick-up — 3,000A — it trips in about 0.5s.

Alan

And the main transformer secondary relay? What's its curve?

主变压器二次侧继电器呢？什么曲线？

Alan

江工: 主变二次侧也是51，但用非常反时限曲线IEEE C1。启动值1.2倍变压器额定电流，时间倍率0.5。这样馈线故障时馈线继电器先动作——馈线0.5秒而主变 1.2秒，有0.7秒的配合裕度。

The main transformer secondary also uses 51, but with a very inverse curve per IEEE C1. Pick-up 1.2× transformer rated current, time dial 0.5. So for a feeder fault, the feeder relay operates first — feeder at 0.5s vs main transformer at 1.2s, giving 0.7s of coordination margin.

Alan

同时还设了50速断——瞬动保护，启动值设为穿过变压器的最大故障电流的 1.3倍。这样它只对变压器内部故障动作，不会对馈线故障误动。

There's also a 50 instantaneous element — set at 1.3× the maximum through-fault current of the transformer. This way it only operates for transformer internal faults and won't misoperate for feeder faults.

Alan

Good coordination. What about the transformer differential?

配合得不错。变压器差动保护呢？

Alan

江工: 我们设了87T——变压器差动保护。动作值为0.3 pu，采用双斜率特性：斜率1 为25%到拐点2 pu，斜率2为60%以上。差动保护涵盖变压器整个区域——高压套管CT到低压套管CT。跟51过流配合——差动对内部故障速动，过流做后备。

We have the 87T — transformer differential. Pick-up is 0.3 pu with a dual-slope characteristic: Slope 1 at 25% up to the knee point at 2 pu, Slope 2 at 60% beyond. The differential covers the entire zone from HV bushing CTs to LV bushing CTs. It coordinates with the 51 overcurrent — diff for fast internal faults, overcurrent as backup.

Alan

And the grid interconnection? The utility has their own requirements for anti-islanding and ride-through.

电网互联呢？电力公司有他们自己的反孤岛和穿越要求。

Alan

江工: 我们装了专用的电网保护继电器——有81频率保护（低频81L/高频81H）、59过电压和27欠电压。反孤岛检测通过频率变化率和电压矢量偏移两个原理实现。穿越设置：LVRT——零电压625ms不脱网，HVRT——1.2pu电压持续1秒。

We installed a dedicated grid protection relay — with 81 frequency (under 81L/over 81H), 59 overvoltage, and 27 under- voltage. Anti-islanding uses both rate-of-change-of-frequency (ROCOF) and vector shift. Ride-through: LVRT — zero voltage for 625ms without tripping, HVRT — 1.2 pu voltage for 1s.

Relay Commissioning — Injection Testing and Logic Verification

Feeder relay FDR-07 is installed, wired, and settings are downloaded. Now we'll inject secondary current and voltage with the relay test set to verify each protection function.

Test set connected. Simulating three-phase current. First, test 51 overcurrent — injecting 1.5× pick-up current... relay picks up at the calculated time of 2.1s, timer starts... trip contact closes. Operating time within 2% of TCC calculation. Pass.

Now test 50 instantaneous — injecting 10A (8,000A primary, above pick-up). Relay trips in 25ms — spec is within 30ms for instantaneous. Pass.

Test the directional element too — inject voltage and current for faults in forward and reverse directions. Confirm it trips for forward, doesn't trip for reverse.

While you're doing protection tests, I'm monitoring on SCADA. For every function tested, I see the events and alarms coming in correctly on SCADA. Trip signal, breaker status change, protection start — all timestamped correctly in the SOE. Protection-to-SCADA communication is working.

Finally, do the trip circuit supervision test — from relay trip contact all the way to the breaker trip coil. Relay sends trip command, auxiliary relay operates, trip coil energizes, breaker opens. The entire circuit is intact with no breaks.

Breaker position shows as "open" on SCADA. Interlock logic is also verified — breaker refuses to close when closing conditions aren't met.

All protection functions tested and passed. FDR-07 protection is ready for service. Next — main transformer relay FDR-01.