1.發(fā)電機失磁保護
1. Generator loss of excitation protection
東莞發(fā)電機維修告訴你失磁保護作為發(fā)電機勵磁電流異常下降或完全消失的失磁故障保護。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)電機過激磁保護
2. Generator overexcitation protection
過激磁保護是反應發(fā)電機因頻率降低或者電壓過高引起鐵芯工作磁密過高的保護。
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)電機定子接地保護
3. Generator stator grounding protection
發(fā)電機定子接地保護作為發(fā)電機定子單相接地故障保護，由基波零序電壓部分和三次諧波電壓兩部分組成，基波零序電壓保護機端至機尾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)電機定子匝間保護
4. Generator stator interturn protection
保護由縱向零序電壓和故障分呈負序方向判據(jù)構(gòu)成,設置PT斷線閉鎖措施，作為發(fā)電機內(nèi)部匝間、相間短路以及定子繞組開焊的主保護。
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
5. Out of step protection
保護采用三阻抗元件，發(fā)動機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
6. Low frequency accumulation protection
低頻累加保護反應系統(tǒng)頻率降低對汽輪機影響的累積效應，保護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閉鎖(即發(fā)電機退出運行時低頻累加保護也退出運行)，累計系統(tǒng)頻率低于頻率定值47.5Hz的時間，當累計時間達到整定值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.勵磁回路過負荷保護
7. Excitation circuit overload protection
勵磁回路過負荷保護用作轉(zhuǎn)子勵磁回路過流或過負荷的保護，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)電機轉(zhuǎn)子一點接地保護
8. Generator rotor one-point grounding protection
發(fā)電機轉(zhuǎn)子一點接地保護用于反應發(fā)電機轉(zhuǎn)子回路一點接地故障，保護采用乒乓式切換原理，輪流采樣轉(zhuǎn)子回路正、負極對地電壓，通過求解兩個不同的接地回路方程，實時計算轉(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)電機對稱過負荷保護
9. Generator symmetrical overload protection
保護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)電機負序過負荷保護
10. Generator negative sequence overload protection
保護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)電機組長期允許的負序電流值和躲過大負荷下負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)電機過電壓保護
11. Generator overvoltage protection
在發(fā)電機并網(wǎng)前，如機端電壓達到1.3倍額定值時，發(fā)電機過電壓經(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)電機縱差保護
12. Generator longitudinal differential protection
按由差動元件兩側(cè)輸入電流的不同進行分類，可以分成完全縱差保護和不完全保護兩類。
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.