节点文献
新型变压器式可控电抗器技术研究
Research on a Novel Transformer-type Controllable Reactor
【作者】 张宇；
【导师】 陈乔夫；
【作者基本信息】 华中科技大学 ， 电机与电器， 2009， 博士
【摘要】 可控电抗器作为一种常见的交流柔性输电设备，在无功调节、电压稳定以及电力负载特性改善等各方面有着广泛的用途。本文在总结国内外有关可控电抗器技术、以及本项目组研究成果的基础上，提出了一种新型的变压器式“混合调节型”可控电抗器方案。该电抗器在性能与成本上都有着比较大的优势。本文注重工程实用，主要围绕单相并联型电抗器，对其工作模型、控制方法、以及样机设计、应用作了全方面的分析和介绍，并以试验对其进行了验证。文章的主要内容包括：对本项目组已有的“基于磁通补偿的可控电抗器”技术进行了总结，解决了应用中多个控制绕组与单个控制绕组统一性的问题。在此基础上，进行概念拓展，提出了通过“线性二端口网络”端口的控制得到可控电抗的一般性原理，探讨了这类电抗器的设计原则。引入“分级调节”与“连续调节”结合的观点，提出了一种新型的变压器式“混合调节型”可控电抗器方案，给出了理论分析和实现方法；解决了开关投切实现电抗“分级调节”在工程实现上的一些关键性问题。与原有的电抗器方案相比，它具有成本更低、性能更为优越的特点。提出了新型可控电抗器本体的设计和实现方法。并借助ANSYS软件，成功设计出一套单相额定电压6kV、容量630kVA的电抗器样机，并通过参数实测进行了验证。针对该电抗器的PWM逆变器控制系统进行了深入研究分析。文中以常见的三角载波电流控制技术为基础，建立了控制系统的模型，对它的稳定运行条件、功率平衡等方面进行了详细的研究；提出了适合的两种控制方案：电流、直流电压双闭环控制，直流电压不控的“自然电流控制”，分析了它们的可行性、工作特点以及使用条件；最后，根据运行特点，提出了逆变器主电路相关参数的设计原则和方法。通过对样机的试验验证了文中提出的新型电抗器理论、设计、运行方案的正确性和可行性，同时，证明该电抗器具有良好的运行性能，能够充分满足电抗值或容量大范围连续可调，并且具有控制精度高、谐波输出少，响应速度快等优点。介绍了项目开发中已进行的一些主要工作，解决了可控电抗器应用于“自动调谐型消弧线圈”的一些关键性问题：对消弧线圈装置启动和退出故障补偿的判据设置、初始电抗设定等应用事项提出了新的见解；提出了一种改进型的电网对地电容的检测方案及数据处理算法，在传统方案的基础上提高了实时性、准确性，使其实现更为简便；介绍了已有样机开发基础及试验研究情况，并以试验结果证实文中新型可控电抗器的优越性。
【Abstract】 Controllable reactors (CR) are general FACTS (Flexible AC Transmission System) apparatus, which have been widely used for regulating reactive power, stabilizing voltage and improving the electrical load character in the power system. In this dissertation, based on the comprehensively summarizing of the present development reactance-controlled techniques and the existing research productions of ourselves project team, a novel CR of transformer type is brought up, which has more advanced performances and costs less. Emphasizing the practice, over-all analysis and introduction for a single-phase shunt apparatus is provided on model establishing, control strategies, prototype designing and application, which verified by the experiment results at the same time. For detail, the original researches of the author are listed as following:Generalizing and deepening of "CR based on transformer magnetic flux compensation" is supplied. The consistency of multiple-windings and single-winding structure for this CR is discussed; and common reactance-adjusting principle by control of "linear two-port network" is provided.By combination of "stepping" and "infinitive" regulating, a novel hybrid controllable reactor of transformer type is proposed. The principle and operating analysis is provided; as well as some key problems about reactance stepping regulated with switches are settled. The comparison between the old and new CR technique is offered, which approves that the former have less cost and far more outstanding performance.Designing calculation and realization approaches for the reactor entity of the new CR are discussed; and with the aiding of ANSYS software, a single-phase rated 6kV, 630kVA prototype is designed successful, and the expected and measuring values of the impedance parameters are approximate.Embedded analysis for the PWM (Pulse width modulation) inverter-control system of the apparatus is provided. First, based on the conventional triangular carrier current control method for voltage source inverter, the model of the control system is established, and the stability and power balance of it is studied. Then, two control strategies for the system are brought up: close loop control for both current and DC side voltage, also the close loop control for only current, meanwhile, feasibility, operating characters and working conditions of control strategies are analyzed. Last, the determinations of main circuit parameters for the control system are provided.The experiment for the prototype verify the feasibility of the whole theoretical analysis, designing and operating schemes, as well as the excellent characteristics of the novel controllable reactor such as high control accuracy, little harmonic, fast response, wide continuous-adjusting range, etc.Some work of the engineering development for the CR applying in automatic tuning ASC (arc-suppression coil) is introduced. Some new opinions are offered about ASC devoting and exiting operation, value setting of initial reactance, etc: a novel method for measuring capacitive current and distinguishing high-resistance grounding of distributing network is presented, together, a adapting signal signal-processing algorithm is put forward, comparing to the traditional schemes, the new method has merits such as more real-time, accurate, and convenient. The researching progress of prototype is reported, and the experiment results declare the superiority of the new controllable reactor technology too.