本文選題：雙饋風力發(fā)電機 + 故障檢測��； 參考：《河南師范大學》2017年碩士論文

【摘要】：近幾年來,雙饋風力發(fā)電機以其獨特的結(jié)構(gòu)被廣泛應用在發(fā)電系統(tǒng)中,能夠?qū)崿F(xiàn)變速恒頻發(fā)電,并且具有相對較小的勵磁容量。當電網(wǎng)處于正常運行狀態(tài)時,雙饋風力發(fā)電系統(tǒng)的控制策略已經(jīng)趨于成熟,目前主要的研究動向是從電網(wǎng)正常運行條件下轉(zhuǎn)為電網(wǎng)故障運行條件下,使雙饋風力發(fā)電機在故障條件下實現(xiàn)不脫網(wǎng)運行,避免造成電網(wǎng)大面積癱瘓。本文主要研究的是:在電網(wǎng)發(fā)生單一的跌落以及混合跌落故障下,采用雙饋風力發(fā)電系統(tǒng)磁鏈預測同步弱磁控制策略,以保證雙饋風力發(fā)電機在低電壓下安全工作。本文首先分析了一種快速并且有效的電網(wǎng)電壓故障檢測方式。因為雙饋風力發(fā)電機定子直接與電網(wǎng)掛接,一旦電網(wǎng)電壓降落,對其影響比較大,為了保證在電網(wǎng)故障瞬間能夠快速切換至故障下的控制策略,本文提出了電網(wǎng)電壓的幅值和相位檢測的方法,達到快速準確檢測電網(wǎng)電壓跌落的目的。其次論文采取了兩相靜止坐標系下雙饋風力發(fā)電機的矢量模型,詳細介紹了雙饋風力發(fā)電系統(tǒng)在電網(wǎng)電壓正常情況下采用的比例諧振控制,此控制算法簡單,沒有多余的補償項,能夠?qū)崿F(xiàn)被控量的無靜差控制,提高了控制系統(tǒng)的魯棒性。當電網(wǎng)電壓發(fā)生跌落故障時,雙饋風力發(fā)電系統(tǒng)的定子磁鏈在電網(wǎng)發(fā)生對稱跌落時出現(xiàn)的直流分量以及不對稱跌落時出現(xiàn)的直流和負序分量,造成了很大的轉(zhuǎn)差率,從而在轉(zhuǎn)子回路形成較高的暫態(tài)過電流。本文依據(jù)其數(shù)學模型,分析得到了電網(wǎng)電壓正常運行時和電網(wǎng)電壓降低情況下的暫態(tài)電磁關(guān)系,同時結(jié)合附圖對電網(wǎng)正常運行時和電網(wǎng)電壓降低瞬間雙饋發(fā)電機定、轉(zhuǎn)子磁場的磁路路徑變化進行分析,為下文控制策略的提出奠定了理論基礎(chǔ)。為了提高雙饋風力發(fā)電系統(tǒng)在電網(wǎng)電壓降低情況下的安全運行能力,本文提出了一種磁鏈預測同步弱磁控制策略。分析了電網(wǎng)電壓降低的情況下定轉(zhuǎn)子磁鏈的變化規(guī)律,在此基礎(chǔ)上,使轉(zhuǎn)子磁鏈對定子磁鏈實時跟蹤,實現(xiàn)定轉(zhuǎn)子磁鏈同增同減,本質(zhì)上減少了故障期間的轉(zhuǎn)差,從而減小故障期間定轉(zhuǎn)子過電流。并且推導了兩相靜止坐標系下的定轉(zhuǎn)子磁鏈關(guān)系以獲取最優(yōu)轉(zhuǎn)子磁鏈參考值。最后通過對轉(zhuǎn)子磁鏈進行無差拍預測控制實現(xiàn)故障期間定轉(zhuǎn)子磁鏈的快速同步,削弱定轉(zhuǎn)子磁鏈之間的相互作用,在電網(wǎng)電壓降低的情況下實現(xiàn)了雙饋風力發(fā)電機的不脫網(wǎng)運行。本論文最后通過運行結(jié)果表明,所提磁鏈預測同步弱磁控制策略結(jié)構(gòu)簡單,具有較快的動態(tài)響應速度,可以有效抑制定、轉(zhuǎn)子過電流,消除故障期間的電磁轉(zhuǎn)矩大范圍波動對風力機組的機械沖擊,表明了雙饋風力發(fā)電系統(tǒng)在電網(wǎng)電壓降低的情況下仍然具有良好的運行品質(zhì)。文章最后為了進一步驗證控制策略的適用性,設(shè)置電網(wǎng)電壓發(fā)生不同類型的電壓跌落故障,所驗證類型從電網(wǎng)電壓出現(xiàn)三相對稱跌落故障過渡到更為普遍出現(xiàn)的不對稱跌落故障。對運行結(jié)果進行分析可以得到:雙饋風力發(fā)電系統(tǒng)磁鏈預測同步弱磁控制策略得到的轉(zhuǎn)子最大電流都可以控制在系統(tǒng)所允許的最大值以內(nèi)。
[Abstract]:In recent years, doubly fed wind generator has been widely used in power generation system because of its unique structure. It can achieve variable speed constant frequency power generation and has relatively small excitation capacity. When the power grid is in normal operating state, the control strategy of doubly fed wind power generation system has become mature. Under the condition of normal operation, the doubly fed wind generator can not be removed from the network under the condition of fault operation and avoid the large area paralysis of the power grid. This paper mainly studies the synchronous weak magnetic control strategy using the magnetic chain of doubly fed wind power generation system under a single drop and mixed fall fault in the power grid. In order to ensure the safe operation of the doubly fed wind generator under low voltage. This paper first analyzes a fast and effective method for detecting voltage faults in the power grid, because the stator of the doubly fed wind generator is directly connected with the power grid. Once the voltage of the power grid is landed, it has a large impact on it, in order to ensure fast switching to the power grid fault. In this paper, the method of amplitude and phase detection of power grid voltage is proposed in this paper to detect the voltage drop of power grid quickly and accurately. Secondly, the vector model of doubly fed wind generator in two phase stationary coordinate system is adopted in this paper, and the ratio of the doubly fed wind power generation system under the normal voltage condition of the power grid is introduced in detail. In the case of resonant control, this control algorithm is simple and has no excess compensation. It can realize the control of the controlled quantity without static difference, and improve the robustness of the control system. When the power grid voltage falls down, the stator flux of the doubly fed wind power generation system appears when the power grid occurs symmetrically and the asymmetrical fall occurs. In this paper, the transient electromagnetic relationship between the normal operation of the grid voltage and the decrease of the voltage of the power grid is obtained. At the same time, the double feed of the normal operation of the power grid and the voltage reduction of the power grid is presented in this paper. The change of magnetic path path of the generator stator and rotor magnetic field is analyzed, which lays the theoretical foundation for the following control strategy. In order to improve the safe operation ability of the doubly fed wind power generation system under the voltage reduction of the power grid, this paper proposes a magnetic chain prediction synchronization weak magnetic control strategy. On the basis of the change law of the rotor flux, the rotor flux can track the stator flux in real time to achieve the same increase and decrease of the stator and rotor flux. In essence, the rotor flux decreases during the fault, thus reducing the over current of the rotor during the fault, and derives the relationship between the stator and rotor flux in the two phase stationary coordinate system so as to obtain the optimal rotor flux linkage. At the end of the test, the rotor flux linkage is predicted to realize the fast synchronization of the stator and rotor flux in the fault period, weaken the interaction between the stator and rotor flux, and realize the non net operation of the doubly fed wind generator under the condition of the voltage reduction of the power grid. The weak magnetic control strategy has a simple structure and a fast dynamic response speed. It can effectively suppress the fixed, overcurrent of the rotor and eliminate the mechanical impact of the large electromagnetic torque fluctuation on the wind turbine during the fault. It shows that the doubly fed wind power generation system still has a good running quality when the voltage of the power grid is reduced. The applicability of the control strategy is further verified, and the voltage drop fault of different types of power grid voltage is set up. The verification type transition from the three-phase symmetrical fall fault of the power grid voltage to the more common asymmetrical fall fault. The maximum current of the rotor obtained by the magnetic control strategy can be controlled within the maximum allowable value of the system.
【學位授予單位】：河南師范大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TM315

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相關(guān)期刊論文 前10條

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本文編號：2108770