【導(dǎo)讀】針對(duì)這些問題提出了相應(yīng)的解決建議和措施，以及更好地利用風(fēng)力發(fā)電。人們普遍都能夠接受，可再生能源發(fā)電是未來電力供應(yīng)的必然趨勢(shì)。由于電力需求增長(zhǎng)快速，對(duì)以化。當(dāng)大型風(fēng)電場(chǎng)成為主流時(shí)，風(fēng)力發(fā)電越來越受歡迎。大型風(fēng)電場(chǎng)的電力系統(tǒng)具有很大的容量，動(dòng)態(tài)隨機(jī)性，這將會(huì)挑戰(zhàn)電力系統(tǒng)的安全性和可靠性。供電力系統(tǒng)清潔能源的同時(shí)，風(fēng)電場(chǎng)也會(huì)帶來一些對(duì)電力系統(tǒng)不利的因素。這給中國(guó)帶來多達(dá)2604兆瓦的電能，使中國(guó)成為世界第六大的市場(chǎng)。中國(guó)市場(chǎng)在2020年大幅增。長(zhǎng)，這預(yù)計(jì)將繼續(xù)增長(zhǎng)并加快增長(zhǎng)。應(yīng)以加速到中心高度的風(fēng)來計(jì)算風(fēng)電場(chǎng)的輸出。對(duì)于目前的風(fēng)力發(fā)電場(chǎng)，當(dāng)發(fā)生干擾時(shí)，保護(hù)操作通常是切斷風(fēng)電場(chǎng)與電網(wǎng)之間的連接。種時(shí)侯的暫態(tài)穩(wěn)定性是非常重要的，尤其是與大型風(fēng)電場(chǎng)的有機(jī)結(jié)合時(shí)最為重要。

　　

【正文】 s voltage variation bigger but short circuit problem smaller[11]. However, wind power farms will be able to give more and more significant effects on the calculation of short circuit current in future power system operation. The reason is twofold. One is the above stated fact that wind power generation site is usually apart from the conventional electrical power center. It implies that the distribution of short circuit current might make a drastic change, leading to a pletely different short circuit capacity map. The other reason is the fact that more and more wind power generation today are particularly in the form of so called largescale wind farms (hundreds of megawatts). In wind farms a substantial number of individual units are connected together, and the total generation capacity will greatly rise up. Wind farms have great influence on the short circuit capacities of adjacent nodes while the 沈陽農(nóng)業(yè)大學(xué)學(xué)士學(xué)位論文外文翻譯 nodes far apart from PCC are little influenced[9]. Therefore, when wind farms with huge capacities are integrated into the grid, capacities of adjacent transformers and switches may need to be increased. It should be studied further how to determine the influence of wind power generation on the short circuit current ratings of existing electrical equipments on the work. （ 6） System Reserve. Meanwhile, system load forecast will potentially bee less accurate as the amount of wind power generation increases, which in turn influence power system operational scheme and unit mitment. In the case of generation reserve forecasts, this could translate into higher reserve level requirements to cover uncertainties in the availability of wind power generation[8]. （ 7） Frequency Regulation. In order to control power system frequency within defined standards, grid corporations require some power plants to provide frequency control ancillary services. However, as the total amount of wind power generation increases, variation in its output will have a more significant impact on the frequency[8]. （ 8） Protection. As for any proposed expansion of a utility grid, there are problems to be addressed with each application for connection. For connection to the distribution system, the proposed generation must have a relatively low capacity. In general, that part of the work is radial and the protection would be graded to expect fault current to flow outwards from the hulk supply point. Introduction of a generator into the radial work means that fault current can now be supplied which does not flow in the expected direction. A detailed check of the protection settings with the proposed generator in the work model is therefore required. The results of this check may show that the protection will function quite adequately as it is. At the other extreme, it may show that the existing relays cannot protect the work while the new generation and a redesign of the protection is necessary[7]. The power flows between wind farms and the grid are bidirectional, which should be considered during the protections design and configuration. Whatever kind of generators are adopted in wind turbines, integration of a wind farm will increase the fault level of grid and furthermore affect the relay settings of original protection devices of grid. It is probably necessary to add new protection devices and/or modify the relay settings of original protection devices. 風(fēng)力發(fā)電對(duì)電力系統(tǒng)的影響 Particularly if wind farms are connected into distribution works, overloading of circuit breakers may occur with the increase of installed capacity of wind farm[8]. 4． Countermeasures to mitigate wind power generation influence The applications of the reactive pensation equipments, such as static var pensator (SVC) and static synchronous pensator (STATCOM) play an important role in wind power generation to mitigate its influence on the power system. In order to maintain the voltage level, the grid corporation may provide additional or upgraded voltage control facilities. Reactive pensation equipments should be installed in the stepup substation of wind farm, which has a fast response characteristic and can be regulated continuously, such as SVC and STATCOM, etc. In order to mitigate voltage fluctuation and flicker caused by wind power generation, both speed control and pitch angle control should be improved so as to minimize the fluctuation of wind turbine output while maximizing the output of wind turbine. Meanwhile, installation of auxiliary devices on wind farm such as SVC and energy storage device can also mitigate both voltage fluctuation and flicker. In most cases, fastacting reactivepower pensation equipment, including SVC and STATCOM, should be included for improving the transient stability of the work. From the wind power generation side, it can improve the voltage stability of the power system and increase wind power peration by the constant power factor control or constant voltage control. From the grid side, it is of significance to reinforce and change the current work. Voltage source converter (VSC) based HVDC (VSCHVDC) is a transmission system that does not require any additional pensation, as this is inherent in the control of the converters[13]. It will therefore be an excellent tool for bringing wind power into a work, even at weak points in a work and without having to improve the shortcircuit ratio. The active power control capability of VSCHVDC could then be a perfect tool for handling active power/frequency control. It is capable of handling wind power and of reacting rapidly enough to counteract voltage variations i n an excellent way, which can improve the system stability and power quality. 5． Conclusion Wind energy has e a long way since the prototypes of just 25 years ago, and it will probably continue to advance over the next twenty years. There are a number of issues associat