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編號
無錫太湖學(xué)院
畢業(yè)設(shè)計（論文）
相關(guān)資料
題目： AHHC520制粒機(jī)設(shè)計
信機(jī) 系 機(jī)械工程及自動化專業(yè)
學(xué) 號： 0923820
學(xué)生姓名： 魏于沛
指導(dǎo)教師： 俞經(jīng)虎 （職稱：副教授 ）
（職稱： ）
2013年5月25日
目 錄
一、畢業(yè)設(shè)計（論文）開題報告
二、畢業(yè)設(shè)計（論文）外文資料翻譯及原文
三、學(xué)生“畢業(yè)論文（論文）計劃、進(jìn)度、檢查及落實(shí)表”
四、實(shí)習(xí)鑒定表
無錫太湖學(xué)院
畢業(yè)設(shè)計（論文）
開題報告
題目： AHHC520制粒機(jī)設(shè)計
信機(jī) 系 機(jī)械工程及自動化 專業(yè)
學(xué) 號： 0923820
學(xué)生姓名： 魏于沛
指導(dǎo)教師： 俞經(jīng)虎 （職稱：副教授 ）
（職稱： ）
2012年11月24日
課題來源
本課題以某企業(yè)產(chǎn)品設(shè)計需求為背景，以AHHC520制粒機(jī)為研究對象，以高質(zhì)量、低成本、環(huán)保、節(jié)能為指導(dǎo)思想，對AHHC520制粒機(jī)的工作原理、關(guān)鍵部件結(jié)構(gòu)型式、關(guān)鍵部件設(shè)計計算等內(nèi)容展開研究。課題研究成果將對相關(guān)企業(yè)產(chǎn)品的優(yōu)化設(shè)計提供有效的指導(dǎo)，具有較大的理論意義與實(shí)用價值。
科學(xué)依據(jù)（包括課題的科學(xué)意義；國內(nèi)外研究概況、水平和發(fā)展趨勢；應(yīng)用前景等）
（1）課題科學(xué)意義
近年來，我國飼料工業(yè)得到了迅速發(fā)展，特別是體現(xiàn)現(xiàn)代化飼料工業(yè)特征的全價顆粒飼料，越來越被廣大養(yǎng)殖業(yè)者接受。飼料加工設(shè)備，特別是顆粒制粒機(jī)，也隨著飼料工業(yè)的發(fā)展而迅速發(fā)展。我國顆粒制粒機(jī)已走過了從引進(jìn)、仿制到消化吸收、自行設(shè)計制造的過程。多種顆粒飼料制粒機(jī)已廣泛用于顆粒飼料的生產(chǎn)實(shí)踐中。其中最應(yīng)用的最多的是環(huán)模和平模制粒機(jī)。平模制粒機(jī)由于自身結(jié)構(gòu)的局限性在飼料工業(yè)中的應(yīng)用雖沒有環(huán)模制粒機(jī)應(yīng)用廣泛，但因其機(jī)構(gòu)簡單，平模制造容易，維修方便，價格便宜，它還是廣泛應(yīng)用于飼料加工，尤其是漁用飼料，寵物飼料等的加工。此外平模制粒機(jī)還廣泛應(yīng)用于工農(nóng)業(yè)生產(chǎn)中有機(jī)復(fù)合肥料的生產(chǎn)。
（2）國內(nèi)外現(xiàn)狀和發(fā)展趨勢
最早的制粒機(jī)利用的是壓縮成型原理，是由兩個形狀相同而轉(zhuǎn)向相反的滾筒組成，粉料被強(qiáng)制填入凹處而壓縮成各種形狀，如三角形、菱形、橢圓形、圓形等粒料，由于這種機(jī)械壓縮作用時間短，顆粒強(qiáng)度低，生產(chǎn)能力小，現(xiàn)已不多使用。
1910 年 第一臺擠壓式制粒機(jī)研制成功，首先生產(chǎn)出圓柱狀粒料，也是首次使用現(xiàn)今所謂模子。早期的模子固定不動，粉料經(jīng)螺旋擠壓通過通孔模子，擠出的粒料被切刀切斷成所需的顆粒。
平模制粒機(jī)在我國的發(fā)展歷程較短，但比環(huán)模制粒機(jī)發(fā)展要早，其始于六十年代早期,至今有四十多年的歷史。
1986 年 江蘇正昌集團(tuán)公司成功研制出11KW，平模直徑為250mm 的平模制粒機(jī)。
1992 年 國家頒布了平模制粒機(jī)行業(yè)標(biāo)準(zhǔn)，中華人民共和國行業(yè)標(biāo)準(zhǔn)SB/T10122—92，規(guī)定了平模制粒機(jī)的產(chǎn)品分類、技術(shù)要求、試驗(yàn)方法、檢驗(yàn)規(guī)則及標(biāo)志、包裝、運(yùn)輸、貯存。
平模制粒機(jī)由于其制粒顆粒較大，含水量大，因此滿足制粒顆粒多樣化是其一個發(fā)展趨勢。為改進(jìn)顆粒質(zhì)和飼料的營養(yǎng)價值，提高制粒效果，因此能夠完成新的制粒工藝——重復(fù)制粒是其另一發(fā)展趨勢，由于飼料品種的變化，制粒機(jī)壓輥壓模間隙的設(shè)定需要經(jīng)常調(diào)整，為了節(jié)約時間，在線的壓輥調(diào)節(jié)是其又一發(fā)展趨勢，此外顆粒飼料經(jīng)蒸汽熱能、機(jī)械摩擦能和壓力等因素的綜合作用，達(dá)到殺菌、提高飼料消化率的諸多功能，但過度的熱加工會造成熱敏性營養(yǎng)成分的失效，降低飼料效果，有效加工是制粒機(jī)最新的發(fā)展趨勢。
研究內(nèi)容
① 查閱相關(guān)資料，概述顆粒加工及其生產(chǎn)現(xiàn)狀。
② 對現(xiàn)有制粒機(jī)的結(jié)構(gòu)、工作原理及傳動部件的結(jié)構(gòu)、工作原理進(jìn)行分析。
③ 對制粒機(jī)傳動部件的設(shè)計進(jìn)行可行性分析。
④ 對傳動部件進(jìn)行結(jié)構(gòu)設(shè)計，并綜合考慮結(jié)構(gòu)，工藝，裝配及經(jīng)濟(jì)性對傳動部件的各零部件進(jìn)行設(shè)計。
⑤ 對設(shè)計進(jìn)行優(yōu)化，繪制二維、三維零件圖和裝配圖。
擬采取的研究方法、技術(shù)路線、實(shí)驗(yàn)方案及可行性分析
（1）實(shí)驗(yàn)方案
① 制造、外觀的檢驗(yàn)，用檢測器具目測?！ ?
② 空載試驗(yàn)，空載啟動
③ 角荷試驗(yàn)制粒機(jī)空載試驗(yàn)合格后，再進(jìn)行負(fù)荷試驗(yàn)，試驗(yàn)時加人物料，模仿正常工序運(yùn)行30min，目測各密封處不得有滲漏現(xiàn)象。
④ 噪聲檢驗(yàn)制粒機(jī)負(fù)載正常運(yùn)轉(zhuǎn)后，按規(guī)定測試噪聲，其值不大于75dB（A）。
⑤電氣安全檢驗(yàn)，電氣系統(tǒng)的保護(hù)接地電路的連續(xù)性、絕緣電阻、耐壓、保護(hù)接地電路分別按規(guī)定要求檢測。
（2）研究方法
① 查閱相關(guān)資料，概述顆粒加工及其生產(chǎn)現(xiàn)狀。
② 對現(xiàn)有平模制粒機(jī)的結(jié)構(gòu)、工作原理及傳動部件的結(jié)構(gòu)、工作原理進(jìn)行分析。
③ 對平模制粒機(jī)傳動部件的設(shè)計進(jìn)行可行性分析。
④ 對傳動部件進(jìn)行結(jié)構(gòu)設(shè)計，并綜合考慮結(jié)構(gòu)，工藝，裝配及經(jīng)濟(jì)性對傳動部件的各零部件進(jìn)行設(shè)計。
⑤ 對設(shè)計進(jìn)行優(yōu)化，繪制二維、三維零件圖和裝配圖。
研究計劃及預(yù)期成果
研究計劃：
2012年10月12日-2012年12月25日：按照任務(wù)書要求查閱論文相關(guān)參考資料，填寫畢業(yè)設(shè)計開題報告書。
2013年1月11日-2013年3月5日：填寫畢業(yè)實(shí)習(xí)報告。
2013年3月8日-2013年3月14日：按照要求修改畢業(yè)設(shè)計開題報告。
2013年3月15日-2013年3月21日：學(xué)習(xí)并翻譯一篇與畢業(yè)設(shè)計相關(guān)的英文材料。
2013年3月22日-2013年4月11日：初步設(shè)計，根據(jù)需要同步繪制相關(guān)圖紙。
2013年4月12日-2013年4月25日：對設(shè)計進(jìn)行修改校對，并完善圖紙。
2013年4月26日-2013年5月21日：定稿，制作設(shè)計電子版及準(zhǔn)備答辯所需資料。
預(yù)期成果：
以高質(zhì)量、低成本、環(huán)保、節(jié)能為指導(dǎo)思想，對AHHC520制粒機(jī)的工作原理、關(guān)鍵部件結(jié)構(gòu)型式、關(guān)鍵部件設(shè)計計算等內(nèi)容展開研究。課題研究成果將對相關(guān)企業(yè)產(chǎn)品的優(yōu)化設(shè)計提供有效的指導(dǎo)，具有較大的理論意義與實(shí)用價值。
特色或創(chuàng)新之處
① 其創(chuàng)新點(diǎn)主要分布于喂料機(jī)構(gòu)、傳動部分。該方案從整機(jī)運(yùn)行穩(wěn)定性、產(chǎn)量、能耗、產(chǎn)品質(zhì)量等角度著手，改善機(jī)器性能。
② 方案設(shè)計以理論計算為依據(jù)，目的是使設(shè)計方案更合理、更具說服力。同時，繪圖過程中也借助于CAD進(jìn)行了輔助設(shè)計，提高了設(shè)計效率。。
已具備的條件和尚需解決的問題
① 實(shí)驗(yàn)方案思路已經(jīng)非常明確，已經(jīng)具備使用CAD，UG編程仿真的能力和圖像處理方面的知識。
② 使用CAD，UG編程的能力尚需加強(qiáng)。
指導(dǎo)教師意見
指導(dǎo)教師簽名：
年 月 日
教研室（學(xué)科組、研究所）意見
教研室主任簽名：
年 月 日
系意見
主管領(lǐng)導(dǎo)簽名：
年 月 日
英文原文
Impact of Wind Power on the Angular Stability of a Power System
Abstract
Wind energy conversion systems are very different in nature from conventional generators. Therefore dynamic studies must be addressed in order to integrate wind power into the power system. Angular stability assessment of wind power generator is one of main issues in power system security and operation. The angular stability for the wind power generator is determined by its corresponding Critical Clearing Time (CCT). In this paper, the effect of wind power on the transient fault behavior is investigated by replacing the power generated by two main types of wind turbine, increasing gradually a rate of wind power penetration and changing the location of wind resources. The simulation analysis was established on a 14 bus IEEE test system by PSAT/Matlab, which gives access to an extensive library of grid components, and relevant wind turbine model.
Keyword Angular Stability, CCT, Wind Turbine, Wind Penetration, PSAT.
Introduction
A power network is a complex system, which is vulnerable to disturbances. A transient short circuit fault is a very common disturbance in a power system [1]. It upsets the
rotating machines in the vicinity of the fault, causing the speeds of these machines, and the power flows in the network to oscillate. When the short circuit is cleared by disconnecting the faulted line, the generators that have accelerated will decelerate and come back into synchronism with the rest of the system. If they do not, and the system becomes unstable, there is a risk of widespread blackouts and of mechanical damage to generators. So the critical clearing time (CCT) is the maximum time interval by which the fault must be cleared in order to preserve the system stability [2, 3].
There is no doubt that wind power will play a predominant role in adding clean and nonpolluting energy to the country’s grid. However, as more wind turbines are connected to the grid, their impact on the power quality of services populated with wind generation is becoming more evident, so it is important to analyze the transient stability of power system including wind power stations [4].
A three-phase fault is applied to a 14 bus IEEE test system, and cleared by disconnecting the affected line.
In this paper, the focus is limited to determine Critical Clearing Time (CCT) for the several cases by observing the transit behavior simulation of a test system during grid faults using a Matlab power system analyze toolbox (PSAT) [5].
The structure of this paper is as follows. First, the wind model is described briefly; also the wind turbine concepts are described. Then, the test system and the applied models are presented. The oscillation of a group of generators during a fault is analyzed by observing the transient behavior for following cases:
A- Changing a wind source locates.
B- Different generator technologies.
C- Increasing gradually a rate of wind sources penetration.
To conclude, the results are clarified on the basis of existing theories and comparison between different cases in order to choose a best case and avoid a worse one. Wind Model
Wind energy is transformed into mechanical energy by means of a wind turbine whose rotation is transmitted to the generator by means of a mechanical drive train.
The wind-power equation [6, 7] is given by: Pt=1/8ρπd2v3 Cp
where ρ is the air density, r is the turbine radius, ν is the wind speed, and Cp is the turbine power coefficient which represents the power conversion efficiency and it is a function of the ratio of the rotor tip-speed to the wind speed, termed as the tip-speed-ratio (TSR).
Such disturbances are the most common in the grid, the grid disturbances considered in this paper are of short duration, maximum a few hundreds of milliseconds. Since the considered grid disturbances are much faster than wind speed variations, the wind speed can he assumed constant. Therefore, natural wind variations need not be taken into account. The wind speed is set to a constant 15 m/s.
Turbine Models
There are many different types of wind turbines in use around the world, each having its own list of benefits and drawbacks [8]. In this paper two main types of wind turbines are taken into account:
? A constant speed wind turbine (Fig. 1a), which consists of a grid coupled short-circuited induction generator [9]. The wind turbine rotor is connected to the generator through a gearbox. The power extracted from the wind is limited in high wind speeds using the stall effect. No active control systems are used.
? A variable speed wind turbine with wound rotor induction generator (Fig. 1b) – doubly-fed induction generator (DFIG). The rotor winding is supplied using a back-to-back voltage source converter [10]. As in the first case, the wind turbine rotor is coupled to the generator through a gearbox. In high wind speeds the power extracted from the wind is limited by pitching the rotor blades.
Figure 1a. Squirrel cage induction generator
Figure 1b. Doubly-fed induction generator
Test System
The test system for this study is presented in Fig. 2, it is derived from IEEE test system; this network consists of 14 buses, 5 generators, 11 loads and 83 branches. The transformers connecting generators to the grid are adjusted accordingly. Wind turbines are the 2 MW machines described above in section 2.
Note that the generators do not represent a single machine but a group of strongly coupled generators and for this test system the total power is divided as follow:
Table 1. Active power of test system generators
Generator N°
1
2
3
4
5
Power(MW)
615
60
60
25
25
The disturbance investigated is a three-phase short-circuit on Bus number 2. This three-phase fault represents the most severe disturbance for transient stability problems.
It must be noted that all simulations are developed by PSAT (version 2.0.0 β1). Results and Discussions
Impact of Location
In order to assume the impact of the wind power to angular stability of power system, we included a three phase symmetrical fault then we calculate the CCT corresponding to a case without wind source and others cases where a wind source is connected to test system by different Buses.
Figure 2. Base case
Without a Wind Source
The Base Case represents the normal operation of the system without any wind power connected to the system. The critical fault clearing time (CCT) can be determined using transient simulations [3]. For this case, the result is CCT = 196 ms. Fig. 3 shows the speed generators in comparison for a fault clearing time close to the critical clearing time.
In Fig. 3b, the fault introduced has duration of t = 197 ms, so the time is exceeding the stability limit of CCT.
Figure 3a. Rotor speed of all generators at t = 196 ms
Figure 3b. Rotor speed of all generators at t=197 ms
With a Wind Source
After that, one wind turbine generator is connected to system through a transmission line on different buses for evaluating their effect to the angular stability.
Table 2. Results from the simulations for the angular stability on different locations
Bus number
Bus 1
Bus 3
Bus 8
Bus 14
CCT (ms)
186
187
263
220
Compared to the previous case where any wind source was connected, the integration of wind source has increased the transit stability when it was connected at BUS 8 or BUS 14, but on the contrary for cases of BUS 1 and BUS 3, so there is no general statement possible, if wind generation improves transient stability margins or if the impact is rather negative. The answer depends on location of wind resources and the problem has to be analyzed individually for each case.
Effect of Type of Generator Technology
In order to determine the effect of type of generator technology to transit behavior of grid, two types of generators are studied with keeping the same fault and the same location of wind source. Case 1: Fixed Speed
The critical fault clearing time (CCT) can be determined using transient simulations. For this case, where wind source is connected to Bus N°3 the result is CCT = 187 ms. Fig. 4 shows the speed rotor of all generators in comparison for a fault clearing time close to the critical clearing time.
Figure 4a. Rotor speed of all generators at t=187 ms
Case 2: Variable Speed (DFIG Technology)
The fixed speed generator added to Bus 3 is now disconnected and substituted by a doubly-fed induction generator (DFIG) having a same power (2MW). Thus, the change in the technology can be considered and analyzed. The analysis of the CCT results in an increased stability limit compared to Case 1 with only fixed speed generators in service. The time increases to CCT = 216 ms as shown in figure 5 .This means, that the transient network stability is enhanced when DFIG are connected instead of fixed speed generator.
Figure 5a. Rotor speed of all generators at t=216 ms
Figure 5b. Rotor speed of all generators at t=217 ms
Table 3. CCT for two types of turbine technology on several buses
Bus N°
1
3
8
14
CCT for fixed speed(ms)
186
187
263
220
CCT for variable speed(ms)
286
216
300
227
According to results, it is very clearly that the DFIG generator increase the critical clearing time, consequently this type of generator presents best performance than a squirrel cage induction generator concerning the angular stability of grid connected to wind power, it is evident that the Wind power generation with DFIG provides better performance for angular stability after fault clearance owing to its ability to control reactive power.
Effect of wind penetration
In this section, the effect of wind power on the oscillations is investigated by gradually increasing the rate of wind source penetration while observing the transit behavior of system [11].
Table 4. CCT for different rates of wind power penetration
Rate of wind sources penetration (%)
3.18
6.7
14.01
21.65
≥ 22
Installed capacity of Wind sources (MW)
24.96
52.59
109.90
169.95
≥172
CCT (ms)
271
229
151
97
00
From the results, it is concluded that the effect of wind power on power system oscillations depends on the rate of wind power penetration, it has been proven that a high level of wind power penetration such in our case study is must be lower than 22 % of total grid power, otherwise the test system lost its stability.
Conclusion
This paper has mainly focused on the assessment of the angular stability by determinate a critical clearing time (CCT), This was done by observing the behavior of speed generators of the test system included a three phase fault when changing several parameters.
According to previously simulations, the following conclusions are obtained:
? There is no general statement possible, if wind generation improves transient stability margins or if the impact is rather negative. The answer depends on location of wind resources and the problem has to be analyzed individually for each case.
? The effect of type of generator technology in transit stability is very significant and the DFIG generator presents more performance than a squirrel cage induction generator.
? It has been proven that a high level of wind power penetration destabilize the power system when a very large part of the synchronous generation capacity is replaced by wind power. Finally, it very important to note that a calculation of a critical clearing time (CCT) in all previous simulations was done by several times which represent a wasting of effort and time so a numerical method of computation of (CCT) is very required for such transit stability studies.
References
1. Sun T., Chen Z., Blaabjerg F., Voltage recovery of grid-connected wind turbines after a short-circuit fault, Annual Conference of the IEEE Industrial Electronics Society, Virginia, USA, 2003.
2. Saffet Ayasun, Yiqiao Liang, Chika O. Nwankpa, A sensitivity approach for computation of the probability density function of critical clearing time and probability of stability in power system transient stability analysis, Applied Mathematics and Computation, 2006, p. 563.
3. Salman S. K., Teo A. L. I., Investigation into the Estimation of the Critical Clearing Time of a Grid Connected Wind Power Based Embedded Generator, Proceedings of the IEEE/PES transmission and distribution Conference and exhibition 2002, Asia Pacific Pucific, Vol. 11, 2002, p. 975-980.
4. Jauch C., S?rensen P., Norheim I., Rasmussen C. Simulation of the Impact of Wind Power on the Transient Fault Behavior of the Nordic Power System, Electric Power Systems Research, VOL: article in press, available online 24 March, 2006, p. 135-144.
5. Federico Milano, Power System Analysis Toolbox Documentation for PSAT version 2.0.0 β1, July 9, 2006.
6. Soerensen P., Hansen A.D., Pedro Andre Carvalho Rosas, Wind Models for Prediction of Power Fluctuations of Wind Farms, J. Wind Eng. Ind. Aerodyn, 2002, 90, p. 1381-1402.
7. Tang Hong, WuJunling, Zhou Shuangxi, Modeling and Simulation for Small Signal Stability Analysis of Power System Containing Wind Farm, J. Power System Technology, 2004, 28(1), 38-41.
8. Hansen A.D., S?rensen P., Iov F., Blaabjerg F., Initialisation of Grid-Connected Wind Turbine Models in Power-System Simulations, Wind Engineering, 2003, 27(1), p. 21-38.
9. Nandigam K., Chowdhury B. H., Power flow and stability models for induction generators used in wind turbines, IEEE Power Engineering Society General Meeting, 2004, 2, p. 2012-2016.
10. Hansen A. D., Michalke G., Fault ride-through capability of DFIG wind turbines, Renewable Energy, 2007, 32, p. 1594-1610.
11. Ha L. T., Saha T. K., Investigation of Power Loss and Voltage Stability Limits for Large Wind Farm Connections to a Sub-transmission Network, Power Engineering Society General Meeting, 2004, 2, p. 2251-2256.
中文譯文
風(fēng)電對電力系統(tǒng)角穩(wěn)定性的影響
摘要
風(fēng)能轉(zhuǎn)換系統(tǒng)是非常不同的性質(zhì)與傳統(tǒng)發(fā)電機(jī)組。因此，動態(tài)研究必須加以解決，以便將風(fēng)力為動力系統(tǒng)。角穩(wěn)定評估風(fēng)力發(fā)電機(jī)是一個主要問題在電力系統(tǒng)安全運(yùn)行。角穩(wěn)定的風(fēng)力發(fā)電機(jī)是由其相應(yīng)的臨界清除時間（建）。在本文中，風(fēng)力的作用對故障暫態(tài)行為調(diào)查取代產(chǎn)生2種類型的風(fēng)力發(fā)電機(jī)，風(fēng)力逐漸增加的速度滲透和改變位置的風(fēng)力資源。仿真分析是建立在14總線測試系統(tǒng)的軟件/，這使獲得一個廣泛的網(wǎng)格組件，以及相關(guān)的風(fēng)力機(jī)模型。
關(guān)鍵詞：角穩(wěn)定性，橫向，風(fēng)機(jī)，風(fēng)滲透。
引言
電力網(wǎng)絡(luò)是一個復(fù)雜的系統(tǒng)，這是容易受到干擾。瞬態(tài)短路故障是一個非常常見的干擾功率系統(tǒng)。它會在轉(zhuǎn)子附近產(chǎn)生故障，導(dǎo)致這些機(jī)器的轉(zhuǎn)速和功率在網(wǎng)絡(luò)中振蕩。當(dāng)短路清除斷開故障，發(fā)電機(jī)，加速將減速，回到同步與其他系統(tǒng)。如果他們不這樣做，并使系統(tǒng)變得不穩(wěn)定，有可能廣泛停電和造成機(jī)械性損壞發(fā)電機(jī)。因此，臨界清除時間是最大的時間間隔，故障必須清除，以維護(hù)系統(tǒng)的穩(wěn)定性。
毫無疑問的是，風(fēng)力將發(fā)揮主導(dǎo)作用，增加國家電網(wǎng)的清潔無污染能源。然而，隨著越來越多的風(fēng)力發(fā)電機(jī)連接到電網(wǎng)，其影響的電能質(zhì)量服務(wù)人類與生產(chǎn)是越來越明顯，所以重要的是分析電力系統(tǒng)的暫態(tài)穩(wěn)定性，包括風(fēng)力發(fā)電站。
三相故障應(yīng)用到14個總線測試系統(tǒng)，通過斷開和清除影響線。
本文的重點(diǎn)是：以確定臨界清除時間（橫向）的若干情況下觀察運(yùn)輸行為仿真測試系統(tǒng)在電網(wǎng)故障期間使用的電力系統(tǒng)分析工具箱（部分）。
本文的結(jié)構(gòu)如下。首先，風(fēng)模型描述也；風(fēng)機(jī)的概念描述。然后，測試系統(tǒng)和應(yīng)用模型的提出。振蕩的一組發(fā)電機(jī)故障暫態(tài)行為分析觀察下列情況：
風(fēng)模型：風(fēng)能轉(zhuǎn)化為機(jī)械能，通過一個風(fēng)力渦輪的旋轉(zhuǎn)傳遞給發(fā)電機(jī)采用機(jī)械傳動裝置。
風(fēng)力方程給出：Pt=1/8ρπd2v3 Cp
其中ρ是空氣的密度，d是渦輪半徑，ν是風(fēng)速，Cp是風(fēng)力機(jī)將風(fēng)能轉(zhuǎn)換為機(jī)械能的效率，稱風(fēng)能利用系數(shù)，它與風(fēng)速，葉片轉(zhuǎn)速，葉片直徑和槳葉節(jié)距角均有關(guān)系，是葉尖速比和槳葉節(jié)距角的函數(shù)。葉尖速比是葉尖速度除以風(fēng)速。
有許多不同類型的風(fēng)力渦輪機(jī)在世界各地使用，各有其自己的名單的好處和缺點(diǎn)。本文主要類型的風(fēng)力渦輪機(jī)是：
?恒速風(fēng)機(jī)（圖1），其中包括一個網(wǎng)格耦合感應(yīng)發(fā)電機(jī)短路[9 ]。風(fēng)渦輪轉(zhuǎn)子連接到發(fā)電機(jī)通過變速箱。功率提取風(fēng)是有限的，在高風(fēng)速時使用失速效應(yīng)。沒有主動控制系統(tǒng)的使用。
?可變速度風(fēng)力渦輪機(jī)與繞線轉(zhuǎn)子異步發(fā)電機(jī)（圖1 b）–雙饋感應(yīng)發(fā)電機(jī)（雙）。轉(zhuǎn)子繞組供給采用背對背電壓源變換器[ 10]。在第一種情況下，風(fēng)機(jī)轉(zhuǎn)子耦合到電機(jī)通過變速箱。在高風(fēng)速功率提取風(fēng)是有限的俯仰轉(zhuǎn)子葉片。
圖1a鼠籠型異步發(fā)電機(jī)。
圖1b雙饋感應(yīng)發(fā)電機(jī)
測試系統(tǒng)
測試系統(tǒng)研究是在圖2，它是從測試系統(tǒng)；該網(wǎng)絡(luò)由14路總線，5臺發(fā)電機(jī)，11和83分支。發(fā)電機(jī)變壓器連接到網(wǎng)格是相應(yīng)的調(diào)整。風(fēng)力渦輪機(jī)的2兆瓦的機(jī)器上面介紹的2節(jié)。
請注意，發(fā)電機(jī)并不代表一個單一的機(jī)器，而是一組強(qiáng)烈耦合發(fā)電機(jī)，該測試系統(tǒng)總功率分為：
表1 有源電力的發(fā)電機(jī)試驗(yàn)系統(tǒng)
發(fā)電機(jī)N°
1
2
3
4
5
功率（MW）
650
60
60
25
25
干擾調(diào)查是一個三相短路對2號總線。這是最嚴(yán)重的干擾三相故障暫態(tài)穩(wěn)定問題。
結(jié)果與討：
以假設(shè)的影響，風(fēng)力角穩(wěn)定的電力系統(tǒng)，包括一三階段對稱故障然后計算橫向?qū)?yīng)一個沒有風(fēng)等情況下，風(fēng)源連接到測試系統(tǒng)的不同總線。
圖2。
圖2 基本線路
沒有風(fēng)的來源
基本情況是正常的操作系統(tǒng)沒有任何風(fēng)電連接到系統(tǒng)。故障臨界清除時間（建）才能確定使用瞬態(tài)模擬[ 3]。對于這種情況，其結(jié)果是橫向=196毫秒。圖3a顯示轉(zhuǎn)速發(fā)電機(jī)故障清除時間比較接近臨界清除時間。
圖3b中的故障，介紹了時間=197毫秒，所以時間超過穩(wěn)定極限曲線。
圖3a所有發(fā)電機(jī)的轉(zhuǎn)子轉(zhuǎn)速=196毫秒
圖3b所有發(fā)電機(jī)的轉(zhuǎn)子轉(zhuǎn)速=197毫秒
在風(fēng)源之后，一個風(fēng)力發(fā)電機(jī)是連接到系統(tǒng)通過傳輸線路上評價其效果的角穩(wěn)定。
表2。從模擬結(jié)果為角穩(wěn)定在不同的地點(diǎn)
總線
總線1
總線3
總線8
總線14
CCT（ms）
186
187
283
220
相比以前的情況下，任何風(fēng)源連接，整合風(fēng)源增加了運(yùn)輸穩(wěn)定時，它是連接在總線8或1總線4，但是相反的情況下1和3總線總線，所以沒有一般的陳述可能，如果風(fēng)力發(fā)電提高暫態(tài)穩(wěn)定的利潤或如果是相當(dāng)消極的影響。答案取決于風(fēng)能資源和問題進(jìn)行分析，為每個單獨(dú)的情況。
影響類型的發(fā)電機(jī)技術(shù)
為了確定影響類型的發(fā)電技術(shù)，運(yùn)輸行為的網(wǎng)格，2型發(fā)電機(jī)的研究與保持相同的故障和同一地點(diǎn)的風(fēng)能。
案例1：固定速度
故障臨界清除時間（建）才能確定使用瞬態(tài)模擬。對于這種情況，那里的風(fēng)源連接到總線°3結(jié)果是橫向=187毫秒。圖4顯示所有發(fā)電機(jī)轉(zhuǎn)子故障清除時間比較接近臨界清除時間。
圖4a 所有發(fā)電機(jī)的轉(zhuǎn)子轉(zhuǎn)速=187毫秒
圖4b 所有發(fā)電機(jī)的轉(zhuǎn)子轉(zhuǎn)速=188毫秒
案例2：變速（雙饋技術(shù)）
固定發(fā)電機(jī)添加到總線3現(xiàn)在是斷開和取代的雙饋感應(yīng)發(fā)電機(jī)（雙饋）具有相同的功率（兩兆瓦）。因此，變化的技術(shù)可以考慮和分析。分析了橫向的結(jié)果增加穩(wěn)定極限的情況相比，1只固定轉(zhuǎn)速發(fā)電機(jī)服務(wù)。時間增加橫向=216毫秒，如圖5所示。這意味著，在暫態(tài)網(wǎng)絡(luò)穩(wěn)定性增強(qiáng)時，雙饋發(fā)電機(jī)連接而固定測速發(fā)電機(jī)。
圖5a 所有發(fā)電機(jī)的轉(zhuǎn)子轉(zhuǎn)速=216毫秒
圖5b 所有發(fā)電機(jī)的轉(zhuǎn)子轉(zhuǎn)速=217毫秒
比較
分析這方面的更詳細(xì)，表3顯示值為雙饋發(fā)電機(jī)技術(shù)（變速）和異步發(fā)電機(jī)（固定變量）的不同位置上。
表3 建2種汽輪機(jī)技術(shù)的幾個公共總線。
總線N
1
3
8
14
橫向固定速度（ms）
186
187
220
223
橫向變速（ms）
286
216
300
227
根據(jù)研究結(jié)果，這是很清楚的，雙饋發(fā)電機(jī)增加臨界清除時間，因此這類發(fā)生器提出了最佳性能比鼠籠式異步發(fā)電機(jī)的功角穩(wěn)定的網(wǎng)格連接風(fēng)力，顯而易見的是，風(fēng)力發(fā)電，雙饋式提供了更好的性能穩(wěn)定故障消除后，由于角其有能力控制無功功率。
風(fēng)的影響滲透
在本節(jié)中，風(fēng)力的作用振蕩的研究逐漸增加的速度源風(fēng)滲透同時觀察運(yùn)輸系統(tǒng)行為[ 11]。
表4 橫向速度不同的風(fēng)電穿透
風(fēng)資源穿透率（%）
3.18
6.7
14.01
21.65
≥ 22
風(fēng)電總裝機(jī)功率（MW）
24.96
52.59
109.90
169.95
≥172
CCT（ms）
271
229
151
97
0
從結(jié)果，它的結(jié)論是，影響風(fēng)電對電力系統(tǒng)振蕩取決于速度的風(fēng)電穿透，它已被證明，高一級的風(fēng)力滲透在我們的案例研究是必須低于22%的總電網(wǎng)，否則測試系統(tǒng)失穩(wěn)。
結(jié)論
本文主要集中在評估的角穩(wěn)定的確定一個臨界清除時間（建），這是觀察的行為，發(fā)電機(jī)的測試系統(tǒng)包括一三個階段的變化時，幾個參數(shù)故障。
根據(jù)先前的模擬，得出以下結(jié)論：
?一般是沒有聲明，如果風(fēng)力發(fā)電提高暫態(tài)穩(wěn)定的利潤或是相當(dāng)消極的影響。答案取決于風(fēng)能資源和問題進(jìn)行分析，為每個單獨(dú)的情況。
?影響類型的發(fā)電技術(shù)在運(yùn)輸?shù)姆€(wěn)定性是非常重要的和雙饋發(fā)電機(jī)提供了更多的表現(xiàn)比鼠籠式異步發(fā)電機(jī)。
?已經(jīng)證明，高一級的風(fēng)電穿透破壞電力系統(tǒng)時，很大一部分的同步發(fā)電能力，取而代之的是風(fēng)力。
最后，很重要的一個計算一個臨界清除時間（建）在所有以前的模擬進(jìn)行了幾次這是浪費(fèi)時間和精力，數(shù)值計算方法（橫向）是非常需要這種運(yùn)輸?shù)姆€(wěn)定性研究。
References
1. Sun T., Chen Z., Blaabjerg F., Voltage recovery of grid-connected wind turbines after a short-circuit fault, Annual Conference of the IEEE Industrial Electronics Society, Virginia, USA, 2003.
2. Saffet Ayasun, Yiqiao Liang, Chika O. Nwankpa, A sensitivity approach for computation of the probability density function of critical clearing time and probability of stability in power system transient stability analysis, Applied Mathematics and Computation, 2006, p. 563.
3. Salman S. K., Teo A. L. I., Investigation into the Estimation of the Critical Clearing Time of a Grid Connected Wind Power Based Embedded Generator, Proceedings of the IEEE/PES transmission and distribution Conference and exhibition 2002, Asia Pacific Pucific, Vol. 11, 2002, p. 975-980.
4. Jauch C., S?rensen P., Norheim I., Rasmussen C. Simulation of the Impact of Wind Power on the Transient Fault Behavior of the Nordic Power System, Electric Power Systems Research, VOL: article in press, available online 24 March, 2006, p. 135-144.
5. Federico Milano, Power System Analysis Toolbox Documentation for PSAT version 2.0.0 β1, July 9, 2006.
6. Soerensen P., Hansen A.D., Pedro Andre Carvalho Rosas, Wind Models for Prediction of Power Fluctuations of Wind Farms, J. Wind Eng. Ind. Aerodyn, 2002, 90, p. 1381-1402.
7. Tang Hong, WuJunling, Zhou Shuangxi, Modeling and Simulation for Small Signal Stability Analysis of Power System Containing Wind Farm, J. Power System Technology, 2004, 28(1), 38-41.
8. Hansen A.D., S?rensen P., Iov F., Blaabjerg F., Initialisation of Grid-Connected Wind Turbine Models in Power-System Simulations, Wind Engineering, 2003, 27(1), p. 21-38.
9. Nandigam K., Chowdhury B. H., Power flow and stability models for induction generators used in wind turbines, IEEE Power Engineering Society General Meeting, 2004, 2, p. 2012-2016.
10. Hansen A. D., Michalke G., Fault ride-through capability of DFIG wind turbines, Renewable Energy, 2007, 32, p. 1594-1610.
11. Ha L. T., Saha T. K., Investigation of Power Loss and Voltage Stability Limits for Large Wind Farm Connections to a Sub-transmission Network, Power Engineering Society General Meeting, 2004, 2, p. 2251-2256.
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