發(fā)布時間：2018-07-01 17:40

  本文選題：水輪發(fā)電機 + 內(nèi)部故障�。� 參考：《哈爾濱理工大學》2014年碩士論文

【摘要】：水輪發(fā)電機定子繞組內(nèi)部故障破壞力極強，會對發(fā)電機本身甚至電力系統(tǒng)的穩(wěn)定運行造成嚴重影響。因此水輪發(fā)電機組必須配置有效的主保護方案，以便及時檢測出機組的內(nèi)部故障。通常要求發(fā)電機的主保護在故障后1個周波左右動作，此時電機的過渡過程還沒有結束，因此需要準確地計算水輪發(fā)電機定子繞組內(nèi)部故障暫態(tài)過程。 本文基于場路耦合法以矢量磁位和回路電流為求解變量，建立了分析同步發(fā)電機繞組短路故障的數(shù)學模型，，該模型兼顧了多回路分析法和電磁場有限元法的共有優(yōu)點，使分析結果更接近實際情況。 本文以SF600－42/1308水輪發(fā)電機為研究對象，建立了SF600－42/1308水輪發(fā)電機—變壓器—無窮大電網(wǎng)的場路耦合模型。首先，仿真計算了該電機空載狀態(tài)下定子繞組突然三相短路的暫態(tài)過程，并將本文的仿真結果與經(jīng)典的解析公式法進行了對比，驗證了本文分析方法及模型的正確性。 其次，依然保持發(fā)電機為空載狀態(tài)，仿真計算了定子繞組發(fā)生匝間短路、同相異分支短路和相間短路故障的故障分支電流、短接線電流、勵磁電流和非故障分支電流的瞬態(tài)波形。分析了各電流波形的諧波含量，揭示了內(nèi)部故障后各分支電流的特點。并將相應電流的基波幅值與多回路法的分析結果進行了對比，驗證了本文提出的數(shù)學模型分析發(fā)電機內(nèi)部故障的準確性。并且，本文還分析了以上3種內(nèi)部故障的故障分支電流隨短路匝比（差）的變化規(guī)律，以及故障發(fā)生的位置和時刻對故障分支電流的影響。 最后，以匝間短路為例，在額定負載工況下仿真計算了故障后阻尼繞組中的渦流波形。分析了渦流產(chǎn)生的原因，揭示渦流波形的特點。并研究了阻尼繞組節(jié)距、阻尼條直徑和阻尼繞組約束方式對內(nèi)部故障電流量的影響，為進一步研究內(nèi)部故障后阻尼繞組中的渦流提供參考。
[Abstract]:The internal failure of hydrogenerator stator windings is extremely destructive, which will seriously affect the stable operation of the generator itself and even the power system. Therefore, the turbine generator must be equipped with an effective main protection scheme in order to detect the internal faults of the unit in time. The main protection of the generator is usually required to operate at about 1 Zhou Bo after the fault, and the transient process of the motor is not over, so it is necessary to accurately calculate the transient process of the fault in the stator winding of the hydrogenerator. Based on the field circuit coupling method, a mathematical model for the analysis of short circuit faults of synchronous generator windings is established using vector magnetic potential and loop current as the solution variables. The model takes into account the common advantages of the multi-loop analysis method and the electromagnetic field finite element method. The results of the analysis are closer to the actual situation. In this paper, the SF600-42 / 1308 hydrogenerator is taken as the research object, and the field-circuit coupling model of SF600-42 / 1308 hydrogenerator, transformer and infinite power network is established. Firstly, the transient process of the stator winding with three phase short circuit in the no-load state is simulated, and the simulation results are compared with the classical analytical formula method, which verifies the correctness of the analysis method and the model. Secondly, the generator is still in the no-load state. The fault branch current and short connection current of stator winding with inter-turn short circuit, same phase and different branch short circuit and interphase short circuit fault are simulated and calculated. Transient waveform of excitation current and non-fault branch current. The harmonic content of each current waveform is analyzed, and the characteristics of each branch current after internal fault are revealed. The comparison of the fundamental amplitude of the corresponding current with the analysis results of the multi-loop method verifies the accuracy of the mathematical model proposed in this paper for the analysis of the internal faults of the generator. In addition, the variation of fault branch current with short-circuit turn ratio (difference) and the influence of fault location and time on fault branch current are also analyzed in this paper. Finally, taking inter-turn short circuit as an example, the eddy current waveform in damping winding after failure is simulated under rated load condition. The causes of eddy current are analyzed, and the characteristics of eddy current waveform are revealed. The effects of pitch distance of damping winding, diameter of damping strip and restraint mode of damping winding on internal fault current are studied, which provides a reference for further study of eddy current in damping winding after internal fault.
【學位授予單位】：哈爾濱理工大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TM312

【引證文獻】

相關期刊論文 前1條

1 戈寶軍;蘆浩;;定子繞組匝間短路時轉子不平衡徑向磁拉力[J];電力系統(tǒng)及其自動化學報;2017年02期

本文編號：2088553