1.發(fā)電機(jī)失磁保護(hù)
1. Generator loss of excitation protection
東莞發(fā)電機(jī)維修告訴你失磁保護(hù)作為發(fā)電機(jī)勵磁電流異常下降或完全消失的失磁故障保護(hù)。由整定值自動隨有功功率變化的勵磁低電壓Ufd(P)、系統(tǒng)低電壓、靜穩(wěn)阻抗、TV斷線等判據(jù)構(gòu)成，分別動作于發(fā)信號和解列滅磁。
Dongguan generator maintenance tells you that the loss of excitation protection serves as a loss of excitation fault protection for generators with abnormal decrease or complete disappearance of excitation current. Composed of criteria such as excitation low voltage Ufd (P), system low voltage, static impedance, TV disconnection, etc., which automatically vary with the active power according to the set value, they respectively act on signal generation and train de excitation.
2.發(fā)電機(jī)過激磁保護(hù)
2. Generator overexcitation protection
過激磁保護(hù)是反應(yīng)發(fā)電機(jī)因頻率降低或者電壓過高引起鐵芯工作磁密過高的保護(hù)。
Overexcitation protection is a protection that reflects the high magnetic density of the iron core of a generator caused by a decrease in frequency or high voltage.
3.發(fā)電機(jī)定子接地保護(hù)
3. Generator stator grounding protection
發(fā)電機(jī)定子接地保護(hù)作為發(fā)電機(jī)定子單相接地故障保護(hù)，由基波零序電壓部分和三次諧波電壓兩部分組成，基波零序電壓保護(hù)機(jī)端至機(jī)尾95%區(qū)域的定子繞組單相接地故障。
The generator stator grounding protection, as a single-phase grounding fault protection for the generator stator, consists of two parts: the fundamental zero sequence voltage part and the third harmonic voltage part. The fundamental zero sequence voltage protection protects the single-phase grounding fault of the stator winding in the 95% area from the machine end to the tail of the machine.
4.發(fā)電機(jī)定子匝間保護(hù)
4. Generator stator interturn protection
保護(hù)由縱向零序電壓和故障分呈負(fù)序方向判據(jù)構(gòu)成,設(shè)置PT斷線閉鎖措施，作為發(fā)電機(jī)內(nèi)部匝間、相間短路以及定子繞組開焊的主保護(hù)。
The protection is composed of longitudinal zero sequence voltage and negative sequence fault direction criterion, with PT disconnection blocking measures set as the main protection for internal inter turn and inter phase short circuits of the generator and stator winding open welding.

5.失步保護(hù)
5. Out of step protection
保護(hù)采用三阻抗元件，發(fā)動機(jī)通過阻抗的軌跡變化來檢測滑極次數(shù)并確定振蕩中心的位置。
The protection adopts a three impedance element, and the engine detects the number of sliding poles and determines the position of the oscillation center through the trajectory change of impedance.
6.低頻累加保護(hù)
6. Low frequency accumulation protection
低頻累加保護(hù)反應(yīng)系統(tǒng)頻率降低對汽輪機(jī)影響的累積效應(yīng)，保護(hù)由靈敏的頻率繼電器和計數(shù)器組成，經(jīng)出口斷路器輔助接點(diǎn)閉鎖(即發(fā)電機(jī)退出運(yùn)行時低頻累加保護(hù)也退出運(yùn)行)，累計系統(tǒng)頻率低于頻率定值47.5Hz的時間，當(dāng)累計時間達(dá)到整定值3000秒時，經(jīng)延時30秒動作于發(fā)信號。
The low-frequency accumulation protection reflects the cumulative effect of a decrease in system frequency on the steam turbine. The protection consists of sensitive frequency relays and counters, which are locked by the auxiliary contact of the outlet circuit breaker (i.e. the low-frequency accumulation protection also exits operation when the generator exits). The accumulated system frequency is below the frequency setting value of 47.5Hz, and when the accumulated time reaches the set value of 3000 seconds, it acts as a signal after a delay of 30 seconds.
7.勵磁回路過負(fù)荷保護(hù)
7. Excitation circuit overload protection
勵磁回路過負(fù)荷保護(hù)用作轉(zhuǎn)子勵磁回路過流或過負(fù)荷的保護(hù)，接成三相式，由定時限和反時限兩部分組成。
The excitation circuit overload protection is used as a protection for overcurrent or overload in the rotor excitation circuit, connected to a three-phase type, consisting of a fixed time limit and an inverse time limit.
8.發(fā)電機(jī)轉(zhuǎn)子一點(diǎn)接地保護(hù)
8. Generator rotor one-point grounding protection
發(fā)電機(jī)轉(zhuǎn)子一點(diǎn)接地保護(hù)用于反應(yīng)發(fā)電機(jī)轉(zhuǎn)子回路一點(diǎn)接地故障，保護(hù)采用乒乓式切換原理，輪流采樣轉(zhuǎn)子回路正、負(fù)極對地電壓，通過求解兩個不同的接地回路方程，實(shí)時計算轉(zhuǎn)子接地電阻和接地位置。
The one-point grounding protection of the generator rotor is used to reflect a one-point grounding fault in the generator rotor circuit. The protection adopts the ping-pong switching principle and takes turns sampling the positive and negative voltage of the rotor circuit to ground. By solving two different grounding circuit equations, the rotor grounding resistance and grounding position are calculated in real-time.
9.發(fā)電機(jī)對稱過負(fù)荷保護(hù)
9. Generator symmetrical overload protection
保護(hù)裝置由定時限和反時限兩部分組成，定時限部分經(jīng)時限5秒動作于信號。
The protection device consists of a fixed time limit and an inverse time limit, with the fixed time limit acting on the signal after a time limit of 5 seconds.
10.發(fā)電機(jī)負(fù)序過負(fù)荷保護(hù)
10. Generator negative sequence overload protection
保護(hù)裝置由定時限和反時限兩部分組成，定時限動作電流按躲過二手發(fā)電機(jī)組長期允許的負(fù)序電流值和躲過大負(fù)荷下負(fù)序電流濾過器不平衡的電流值整定，經(jīng)時限3秒動作于信號。
The protection device consists of two parts: a fixed time limit and an inverse time limit. The fixed time limit action current is set according to the long-term allowable negative sequence current value of the second-hand generator set and the current value of the negative sequence current filter under maximum load, and acts on the signal after a time limit of 3 seconds.
11.發(fā)電機(jī)過電壓保護(hù)
11. Generator overvoltage protection
在發(fā)電機(jī)并網(wǎng)前，如機(jī)端電壓達(dá)到1.3倍額定值時，發(fā)電機(jī)過電壓經(jīng)延時0.5秒動作于解列滅磁。
Before the generator is connected to the grid, if the terminal voltage reaches 1.3 times the rated value, the generator overvoltage will be triggered by a 0.5 second delay to disconnect and de-excitation.
12.發(fā)電機(jī)縱差保護(hù)
12. Generator longitudinal differential protection
按由差動元件兩側(cè)輸入電流的不同進(jìn)行分類，可以分成完全縱差保護(hù)和不完全保護(hù)兩類。
According to the different input currents on both sides of the differential element, it can be classified into two categories: complete longitudinal differential protection and incomplete protection.