输电线路参数扫频测量新技术的研究与实现

发布时间：2018-08-18 18:22

【摘要】：输电线路工频参数是电力系统进行潮流计算、继电保护整定计算和选择电力系统运行方式等工作之前建立电力系统科学数学模型所需的必备参数,其准确性直接关系到电网的运行安全。由于影响输电线路工频参数的因素较多,而理论计算无法准确得出各种因素对其的影响,因此在我国电力系统运行规程中明确要求对新建或新改造的输电线路在投运前必须进行输电线路工频参数的实测。本文针对常规输电线路工频参数实测方法在测量强干扰、长距离的输电线路工频参数时存在的问题,提出了输电线路参数扫频测量的新方法。该方法为了抑制强工频干扰对测量精度的影响以获得高精度和高可靠的输电线路工频参数值,除了采用偏离工频频率较远的200～2000Hz的三相电压型PWM逆变电源作为扫频测量的激励源外,还同时采用了软件滤波和硬件滤波的信号检测技术。围绕提出的输电线路参数扫频测量方法,本文主要的研究内容概括如下： (1)综合分析了国内外在输电线路工频参数测量领域的研究成果,归纳出目前输电线路工频参数测量中所面临的主要技术问题及研究进展。 (2)对目前应用中的输电线路工频参数异频测量法进行了科学分析,提出了输电线路工频参数扫频测量法,并从理论上对该方法的科学性和可行性进行了分析。为解决长距离输电线路工频参数扫频测量时因分布参数特征值的提取需求解复数超越方程,因而难以用微处理器实现的技术难题,研究了利用长距离输电线路的谐振点来提取输电线路分布参数特征值的方法。 (3)对输电线路工频参数扫频测量方法实现所需的两大关键技术(三相扫频激励源的产生、自适应扫频抗干扰测量技术)进行了研究。 (4)应用电力电子技术、电子测量技术、数字信号处理技术和自适应控制技术,设计并开发了一套智能化输电线路工频参数扫频测量试验装置。 (5)利用扫频测量装置进行了模拟试验与现场试验,试验结果验证了输电线路工频参数扫频测量原理及测量装置的可行性和可靠性。理论研究与系列科学实验表明本课题的研究为输电线路工频参数的测量提供了一套可行的理论和可以应用的智能化测量装置。该研究取得了一整套自主知识产权,其成果可有效提高电力系统继电保护整定精度,对增强电力系统运行的可靠性和安全运行水平具有积极意义。
[Abstract]:Power frequency parameters of transmission lines are the necessary parameters for the establishment of scientific mathematical model of power system before power flow calculation, relay protection setting calculation and selection of power system operation mode, etc. Its accuracy is directly related to the operation safety of power grid. Since there are many factors affecting the power frequency parameters of transmission lines, the influence of various factors on the power frequency parameters can not be accurately obtained by theoretical calculation. Therefore, in the operation rules of power system in our country, it is clearly required to measure the power frequency parameters of new or newly reformed transmission lines before they are put into operation. In this paper, a new method for measuring the power frequency parameters of transmission lines is proposed, aiming at the problems existing in the measurement of the power frequency parameters of the transmission lines with strong interference and long distance by using the conventional method of measuring the power frequency parameters of transmission lines. In order to suppress the influence of strong power frequency interference on measurement accuracy, the method can obtain high accuracy and high reliability power frequency parameters of transmission lines. In addition to the three-phase voltage-mode 200~2000Hz inverter which deviates from the power frequency far away from the power frequency, the three-phase voltage-mode PWM inverter is used as the excitation source for the sweep frequency measurement, and the signal detection techniques of software filtering and hardware filtering are also used. The main research contents of this paper are summarized as follows: (1) the research results in the field of power frequency parameter measurement of transmission lines at home and abroad are comprehensively analyzed. The main technical problems and research progress in the measurement of power frequency parameters of transmission lines are summarized. (2) A scientific analysis is carried out on the different frequency measurement methods of power frequency parameters of transmission lines in current application. In this paper, a method for measuring power frequency parameters of transmission lines is put forward, and the scientific and feasibility of this method is analyzed theoretically. In order to solve the complex transcendental equation of power frequency parameter sweep measurement of long distance transmission line, it is difficult to realize it with microprocessor because of the demand of extracting eigenvalue of distributed parameter. This paper studies the method of extracting the eigenvalue of transmission line distribution parameters by using the resonance point of long distance transmission line. (3) the generation of three-phase frequency sweep excitation source is the two key techniques needed to realize the power frequency parameter sweep measurement method of transmission line. (4) Power electronics technology, electronic measurement technology, digital signal processing technology and adaptive control technology are applied. This paper designs and develops a set of intelligent test equipment for power frequency parameter sweep measurement of transmission line. (5) the simulation test and field test are carried out by using the frequency sweep measurement device. The experimental results verify the feasibility and reliability of the principle of power frequency parameter sweep measurement and the measuring device. Theoretical research and a series of scientific experiments show that this research provides a set of feasible theory and intelligent measuring device for measuring power frequency parameters of transmission lines. The research has obtained a set of independent intellectual property rights, which can effectively improve the setting accuracy of power system relay protection, and have positive significance to enhance the reliability and safe operation level of power system operation.
【学位授予单位】：武汉大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TM75

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