谐波的研究毕业论文外文翻译.doc

附录1随着电力系统的发展以及电力市场的开放，电能质量问题越来越引起广关注。由于各种非线性负载(谐波源)应用普及，产生的谐波对电网的污染日益严重。谐波是目前电力系统中最普遍现象，是电能质量的主要指标。电力系统谐波是电能质量的重要参数之一，随着电力电子技术的发展，大量的非线性负载和各种整流设备被广泛的应用于各行各业，使电网谐波含量大大增加，电能质量下降。谐波给供电众业的安全运行和经济效益带来了巨大影响。所以，抑制谐波污染、改善供电质量成为迫切需要解决的问题。因此，谐波及其抑制技术己成为国内外广泛关注的课题。“谐波”一词起源于声学。有关谐波的数学分析早在18世纪和19世纪就己奠定了良好的基础。傅立叶等人提出的谐波分析方法至今仍在广泛采用。电力系统的谐波问题早在20世纪的20年代和30年代就引起人们的关注。当时在德国，由于使用静止汞弧变流器而造成了电压、电流波形的畸变。1945年J.C.Read发表的有关变流器谐波的论文是早期关于谐波研究的经典论文。到了50年代和60年代，由于高压直流输电技术的发展，发表了大量电力系统谐波问题的论文。E.W.Ximbark在其著作中对此进行了总结70年代以来，由于电力电子技术的快速发展，各种电力电子装置在电力系统、工业、交通及家庭中的应用日益广泛，谐波所造成的危害也日趋严重。世界各国都对谐波问题给予充分关注，定期召开有关谐波问题的学术讨论会。国际电工委员会 (IEC)和国际大电网会议都相继组成了专门的工作组，制定包括供电系统、各项电力设备和用电设备以及家用电器在内的谐波标准，并将谐波干扰问题列入电磁兼容范围内。谐波的研究是很有意义的。首先是因为谐波的危害十分严重，谐波可使电能的生产、传输和利用的效率降低;使电气设备过热、产生振动和噪声，并使绝缘老化，使用寿命缩短，甚至发生故障或烧毁;谐波可引起电力系统局部并联谐振或串联谐振，使谐波含量放大，造成电容器设备烧毁;谐波还会引起继电保护和自动装置误动作，对通信设备产生严重干扰等。谐波研究的意义，还在于其对电力电子技术自身发展的影响。但是，电力电子装置产生的谐波污染己经成为阻碍电力电子技术发展的重大障碍，迫使电力电子领域的研究人员必须对谐波问题进行更为有效的研究。谐波研究的意义，还可以上升到治理环境污染、维护绿色环境来考虑。对电力系统来说，无谐波就是“绿色”的主要标志之一。因此消除谐波污染，己成为电力系统，尤其是电力电子技术中的一个重大课题。谐波研究及其抑制技术己日益成为人们关注的问题.电力公司被迫经营系统接近其热稳定性的限制和因主要障碍，例如环境，偏右的路和电力成本问题传输网络扩容。对输电线路和损失，以及成本在遇到困难的建设新输电线路，往往会限制了可用传输容量。那里很多情况下，经济的能源或储备共享是受限于传输能力和情况并非越来越好。此外，在放宽电力服务环境，是一个有效的电网至关重要的竞争环境，可靠的电力服务。近年来，更高的要求已被列入传输网络及在需求增加将上升由于nonutility发电机和越来越多各公用事业自己竞争加剧。日益增加的需求，长期缺乏规划，以及需要为生成开放电力市场准入公司（发电商）以及公用事业公司的客户，他们都对安全性能的降低和质量下降造成的倾向供应。A电力系统的模型基于谐波功率流的模块化方法在分区及其线性部分系统的非线性部分 。 先前所述的 TCR 分支部分，可用作构建基块的两种非线性设备： SVC 和在可控串补。答： 静功补偿装置 （SVC）SVC (六-脉冲) 的典型配置由组成三个三角洲连接 TCR 分支与并行接地固定或晶闸管开关电容器。 12 脉冲配置被获得同样要在高压直流变换器提供一个30的并行和连接变压器相移两六脉冲 SVCs 之间。射击控制是基本上与电压调节函数在被调整以确保点火延迟通过更改网无功功率注入足够的电压支持SVC。B.控制晶闸管串联电容器 (可控串补)在可控串补的基本配置有一系列电容器连环 TCR 分支的。 一种可调谐的并行像在可控串补与线系列中的 LC 电路。在可控串补的稳态基本功能是有功功率流控制和它主要在电容范围内运行。C.线性网络表示电源系统网络的线性部分 (进口原版)通过在每个谐波索取其导纳矩阵频率。这种方法是简单且功能强大，它允许集中和分布式参数模型和直接的使用和频率依赖性参数的准确表示形式。D.谐波潮流计算谐波功率流为基础的解决方案在是从节点导纳构建块对角矩阵在计算的系统的低压与关联矩阵在频率。 矢量是节点电压 （phasors） 中的向量考虑频率和是的节点矢量从非线性组件的当前注射 (也是 phasors)和独立源。每个 TCR 分支注射在两个网络的谐波电流节点，与对面的迹象。V.RESULTS本节介绍用于突出显示关键功能的结果拟议的模式与牛顿式及其应用谐波功率流的程序。 衔接，重点是计算的时间和鲁棒性而非该操作系统的方面。中原本建议一个弱的径向系统和也上分析，是以示包括一个可控串补自适应图 3。 系统数据载列于附件。SVCs 最初被为了保持沿电压他们正常范围内的 230 千伏输电系统操作。这是一个必要的和重要的任务，特别是在一个弱系统电压配置文件可以在其中显著更改负载变化。此示例系统用来强调谐波失真在电流和电压。在接地的选择在变压器和谐波过滤器的缺乏连接是故意的。第一例是仅 SVC1 连接，但经营研究与射击控制一个奇： 每个 TCR 分支都不同延迟 （110、 120 和 130) 和也有 1 差异正与负半周期触发。这在倍频，发射计划结果以及存在的甚至谐波和三次谐波尽管在 TCR 的三角洲连接分支。牛顿法是非常可靠和准确。电流注入和诺顿等效方法有几乎相同的计算开销每个迭代和一个考虑谐波的数目相对于的线性关系。牛顿法是较昂贵，每个迭代时间已比其他两个方法和其平均的迭代就 (几乎二次) 的非线性关系，谐波的数目。 所有方法都计算非线性注入已计算的开销电流，但牛顿法雅可比矩阵。 同时，解决了牛顿法所有的频率，同时与单个订单的矩阵当电流注入和诺顿等效项方法是顺序的频率耦，解决问题其中是网络中的节点数与是的谐波问题在考虑数。在另一方面牛顿法生产最快由于其小的迭代次数的全面解决方案 （小于六个迭代） 和诺顿等效方法将成为一个只有 80 多个谐波时要考虑，有很好的选择。50 谐波，牛顿法要求 33.4 s。在放松管制或者电力行业改革已创造一个竞争开放的市场环境。在新的环境，传输系统中起着关键作用向所有与会者提供接入提供或消费电力。对传输中的扩张目标放松管制的环境应该从不同的传统的电力工业。因此，新办法标准是必要的。在这个文件中，提出了一种方法来确定最佳传输扩展计划下的放松管制电力系统。建议的方案考虑到在电力市场的不确定性，传输成本和安全性指数作为规划目标，功能扩展。附录2With the development of the power system and the opening of the electricity market，the power quality problem has been received increasing attention. The pollution of the harmonies to the grid increasingly severe，owing to the prevalence of the nonlinear loads(harmonies courses) application. With the development of power system，the power quality is requested to be better and betterHarmonic is the most general phenomenon in power systemAnd harmonic is the main index of power quality.E1ectric power system harmonic is one of the most important parameter. With the development of electric power and electron technology, a number of the nonlinear 10ads and all kinds of commutating equipments are widely applied in every walk of life，what they bring a mass of harmonic current make the content of harmonic increase in the power system and quality of power dropThe harmonic affects the safe operation and economic benefit of power supply enterprises to great extent. So, it is urgent to eliminate harmonic. So the harmonic and its suppression technology have becoming the common concerning topic worldwide. "Harmonic" is derived from the acoustic. The mathematical analysis of the harmonics in the 18th century and early 19th century has laid a good foundation. Fourier and other methods proposed by harmonic analysis is still widely used. Power system harmonic problems attract attention early in the 20th century. At that time in Germany, due to the use of mercury arc converter static caused by the voltage and current waveform distortion. In 1945 JC Read published the paper converter harmonics of the early classic papers on the harmonic. To the 50's and 60's, due to high voltage DC transmission technology, and lots of papers are published about harmonic problems. EWXimbark in his book have been summarized since the 70s, due to the rapid development of power electronics, various power electronic devices in power systems, industrial, transportation and the family is used widely, the harm caused by harmonics that are also more serious. Countries in the world to give full attention to the harmonic problems, regular meetings of the Colloquium harmonic problems. International Ctrotechnical Commission (IEC) and CIGRE are successively formed a special working group to develop including the power supply system, the electrical equipment and electrical equipment and appliances, including harmonic standards, and harmonic interference included within the scope of electromagnetic compatibility. Harmonic problems in China started late, Miss Lu, who actually published in 1988, "Power System armonics," a book about the power harmonic problems in our country more influential writings. Harcourt Road, etc. and only published in 1994, "HVDC transmission system harmonic analysis and filter" is the representation of books published in recent years. Lin Hai Xue, Sun Shuqin, etc., published in 1998, "Harmonic power network," a detailed harmonic analysis. In addition, reunification and Yung Tang Jian Gang, who were so independent translation of the J. Atrilaga book "Power System Harmonics", which also has great influence at home and abroad .Harmonic study is very significant. First, because the danger is very serious harmonics, harmonic power can the reduction, transmission and use of lower efficiency; make electrical equipment, overheating, vibration and noise, and to insulation aging, shorten life, or even failure or burned; power system harmonics can cause partial parallel resonant or series resonant, the harmonic content of amplification, resulting in capacitor equipment destroyed; harmonics also cause malfunction relay protection and automatic devices, communications equipment, serious disturbances. Harmonic of the significance of the power electronic technology is still in its own development. However, now the power electronic devices have generated the harmonic pollution hinders the power of the major obstacles to the development of electronic technology, it forces the researchers to the field of power electronics Bixu right Harmonics by a more Youxiao on harmonic of the significance of environmental pollution can rise to above, to maintain the green environment to consider. The power system, the non-harmonic is "green" one of the main signs. Therefore, to eliminate harmonic pollution has become a power system, especially in power electronics a major issue. Harmonic and its suppression technology has increasingly become of concern.The FACTS devices (Flexible AC Transmission Systems)could be a means to carry out this function without the drawbacks of the electromechanical devices such as slowness and wear. FACTS can improve the stability of network, such as the transient and the small signal stability, and can reduce the flow of heavily loaded lines and support voltages by controlling their parameters including series impedance, shunt impedance, current, and voltage and phase angle. Controlling the power flows in the network leads to reduce the flow of heavily loaded lines, increasing the ability of system load, less system loss and improving security of the system. The increasing interest in these devices is essentially due to recently development in high power electronics that has made these devices cost effective and increased loading of power systems, combined with deregulation of power industry . On account of considerable costs of FACTS devices, it is important to place them in optimal location. There are several papers represented in literature, which deal with the optimal placement of FACTS controllers with heuristic methods. References deal with the location of FACTS devices from the security index point of view. And discusses the location of TCPAR, TCSC, UPFC for enhancement of power system security with real power flow performance index. In 6 three heuristic methods (Ta search, Simulated annealing and Genetic algorithm) are applied to find the optimal location of FACTS devices in a power system.IV. POWER SYSTEM MODELThe modular approach to the harmonic power flow is based on the partition of the system in its linear part and nonlinear part .The TCR branch described in the previoussection can be used as the building block for two different nonlinear apparatus: the SVC and the TCSC.A. Static VAr Compensator (SVC)A typical configuration of the SVC (six-pulse) consists of three delta-connected TCR branches in parallel with grounded fixed or thyristor-switched capacitor banks. A 12-pulse configuration is obtained similarly to the HVDC converter, with parallel and connected transformers providing a 30 phase-shift between two six-pulse SVCs.The firing control is basically associated with the voltage regulation function, with the firing delay being adjusted to ensure adequate voltage support by changing the net reactive power injection of the SVC.B. Thyristor-Controlled Series Capacitor The basic configuration of the TCSC has a series capacitor shunted by a TCR branch. The TCSC acts like a tunable parallel LC circuit in series with the line. The steady-state basic function of the TCSC is active power flow control and it mostly operates within the capacitive range. C. Linear Network The linear part of the power system network is represented by its admittance matrix obtained at each harmonic frequency . This approach is simple and powerful, allowing the use of lumped and distributed parameter models and a direct and accurate representation of frequency-dependent parameters. D. Harmonic Power FlowThe harmonic power flow is based on the solution of where is a block diagonal atrix built from the nodal admittance matrices associated with the LP of the system, calculated at frequency .Vector is the vector of nodal voltages (phasors) at the considered frequencies and is the vector of nodal current injections (also phasors) from the nonlinear components and the independent sources. Each TCR branch injects harmonic currents at two network nodes , with opposite signs. V. RESULTSThis section presents results intended to highlight key features of the proposed model and its application in a Newton-type harmonic power flow program. The focus is on convergence, computational time, and robustness rather than the operational aspects of the system. A weak radial system, originally proposed in 14 and alsoanalyzed in 15, is adapted to include a TCSC as shown in Fig. 3. The system data are presented in Appendix E. The SVCs are originally designed to keep the voltages along the 230-kV transmission system within their normal range of operation. This is a necessary and important task, especially in a weak system where the voltage profile can significantly change with the load variations. This example system is used to emphasize harmonic distortion in currents and voltages. The choice of the groundedconnection for the transformers and the lack of harmonic filters are intentional.The first case is studied with only SVC1 connected, but operating with an odd firing control: each TCR branch has a different delay and there is also a 1 difference between the positive and the negative half-cycle firings. This firing scheme results in noncharacteristic harmonic generation, with the presence of even harmonics and third harmonic (and multiples) despite the delta connection of the TCR branches. The Newton method is very robust and accurate, yielding fast convergence to very strict tolerance. Harmonic power flowconvergence took 32 and 96 iterations, respectively, to reach the same tolerance, considering 50 harmonics. Fig. 6 presents the average iteration time for these solution methods. The current injection and Norton equivalent methods have almost the same computational cost per iteration and a linear relationship with respect to the number of harmonics considered. The Newton method is more expensive per iteration than the other two methods and its average iteration time has a nonlinear relationship (almost quadratic) with respect to the number of harmonics. All methods calculate the nonlinear injected currents, but the Newton method has the overhead of calculating the Jacobian matrix. Also, the ewton method solves for all frequencies at the same time, with a single matrix of order , while the current injection and Norton equivalent methods are frequency-decoupled, solving problems of order , where is the number of nodes in the network and is the number of harmonics considered in the problem. On the other hand, the Newton method produced the fastest overall solution due to its small number of iterations (less than six iterations) and the Norton quivalent method will become a good option only if more than 80 harmonics are to be onsidered. With 50 harmonics, the Newton method required 33.4 s .The deregulation or reforming of electric power industry has created a competitive open market environment. In the new environment, the transmission system plays a critical role in providing access to all participants to deliver or consume the electric power. The objective for transmission expansion in the deregulated environment should be different from that in the traditional power industry. Therefore, new approaches and criteria are needed.