节点文献
基于空间磁场的同杆并架双回线动态物理模型的研究
Study on Dynamic Physical Model of Double-circuit Transmission Lines on Same Tower Based on the Analysis of Space Magnetic Field
【作者】 吴彤;
【作者基本信息】 华中科技大学 , 电力系统及其自动化, 2011, 博士
【摘要】 近年来,随着我国国民经济快速发展,电力需求与日俱增,对电网输电容量的要求也日益提高。同杆并架双回线路输电技术以其在单位走廊的输电容量、输电效率和投资回报率等方面的优势,在我国得到了长足发展和广泛应用。但这种同杆并架双回线具有复杂的故障类型和暂态特性,已不能继续采用在单回线上广泛应用的故障分析原理和继电保护配置,需要开展针对性的研究,研制相应的保护和控制装置。由于保护和控制装置的性能分析和评估依赖于理论研究和试验结果,需要通过在能够真实反映同杆并架双回线路物理特性的物理模型上开展动模实验来加以验证,而现有同杆并架双回线路模型不能很好地反映线路参数特征,存在一定的局限性,因此本文创造性地提出了一种基于空间磁场耦合的同杆并架输电线路模型。该模型可以全面反映两回线各相之间所有的互感,精确地反映同杆并架双回线路故障时的电气量变化特征。论文首先对同杆并架双回线路的应用和研究现状进行了分析和综述,分析了前人提出的几种同杆并架模型的基本原理和存在的主要问题;阐述了空间磁场同杆并架模型研制的特点和必要性。然后针对几种双回架空线不同的线路特性,分析了实际工程中所关注的同杆并架双回线各序阻抗的计算方法,为线路参数的实测和仿真提供理论依据和参考数据。利用PSCAD/EMTDC电磁暂态仿真软件,根据实际工程中比较常用的杆塔模型来搭建同杆并架双回输电线路数字仿真模型,得到了同杆并架线路的稳态数字仿真参数。本文提出的“基于空间磁场耦合的同杆并架输电线路模型”的设计思想与实际线路自、互感产生的原理一致,是通过各线路通电后所产生的空间磁场耦合产生自感和互感。模型采用三分段换位结构设计,首先采用多个线圈和铁芯来构建单个分段模型磁通回路;然后接线并进行参数的测试与调整,建立分段模型;最后采用三个分段换位串联得到完整的空间磁场同杆并架模型。论文对模型的构建过程进行了详细的说明,并根据数字仿真出的同杆并架线路的参数,通过调节模型线圈的空间位置改变模型参数,建立起了同杆并架线路的物理模型。通过将实际线路参数、数字仿真参数与该空间磁场同杆并架模型的序参数进行比较可以看出,物理模型的序参数能比较精确地反映和模拟实际同杆并架线路的参数和特征。最后介绍了利用该模型开展动模实验的情况,通过故障实验数字仿真进一步证实了该模型的正确性和实用性,为深入研究同杆并架输电线路的特性、开展同杆并架双回输电线路的动模实验研究和继电保护装置的研发与检测提供了良好的实验平台。
【Abstract】 With the development of economy in our country, more and more requirement for electrical power suply and transmission capacity is demanded in recent years. By the advantage of tranmission capacity and efficiency, and the rate of return on investment, it is rapidly developed and widely applicated that the technology of double-circuit transmission lines on same tower. But with the complicated fault type and transient characteristics of the double-circuit transmission lines on same tower, it is no longer suitted for the thnology that the common failure analysis principle and protection configuration of relay used on single-circuit transmission lines. Specific research on devices of relay protection and control must be carried on.It depends on the theory research and experiment result that the performance analysis and evaluation on the relay proctection and control devices, and also needs for the dynamic simulation test on physics model which can truely reflect the physical properties of double-circuit transmission lines on same tower. But the present model can not reflect the circuit parameters characteristics well. So it is presents in this paper that the physical model of double-circuit transmission lines on same tower based on theory of space magnetically coupling. This model can fully response the mutual inductance parameters between phases of double-circuit, and response accurately the electric parameters change characteristics while falure occurs on the double-circuit transmission lines on same tower.First it is analysied and described that the present situation of research and application of double-circuit transmission lines on same tower, analysied the basic principal and main problem of previous physical models of double-circuit transmission lines on same tower. It is described that the characteristics and necessity of the study on double-circuit transmission lines on same tower based on space magnetical theory.According to the circuit characteristics of some kinks of double-circuit transmission lines, it is analized for the theory basis and reference data of the measurement and simulation of circuit characteristics that calculation method on each sequence impedance of double-circuit transmission lines. With the tool of PSCAD/EMTDC, it is achieved by the digital simulation mode of double-circuit transmission lines on same tower with the datas of common tower model commonly used in practical projects, that the steady state digital simulation parameters of double-circuit transmission lines on same tower.The design philosophy of the model is the same with the production principle of self-inductor and mutual-inductor of real transmission line which created by the space magnetically coupling of circuits. It is designed with three segmentation transposition structure, first builds single block model of the magnetic flux loop with multiple coil and iron core, then builds segmented model by connecting the wires and testing and adjusting the parameters. At last builds the full physical model of double-circuit transmission lines on same tower based on theory of space magnetically by conversion series connecting the three subsection. It is detialed descriped that the construction process of physical model. It is built that the physical model of double-circuit transmission lines on same tower by means of adjusting the model papameter with the spatial position of model coil which is descieded by the digital simulating of the circuit parameter.By the comparision of the real line parameters, digital simulation parameters and the sequence parameter of double-circuit transmission lines on same tower based on space magnetical theory, it shows rhat the sequence parameter of physical model can more accuratlly response and simulate the real parameter and character of double-circuit transmission lines on same tower.Finally it is introduced that the dynamic simulation test with this model, and it is also proved that the correctness and practicability of this model by digital simulation of failure experiment. It provides fine experimental plat for the research of dynamic simulation test on double-circuit transmission lines on same tower and the development and testing for relay protection devices.
【Key words】 Double-circuit transmission lines on same tower; Space magnetically coupling; Dynamic simulation; Physical imitation;