基于环境参数估计的输电线路载荷能力研究

发布时间：2018-01-22 19:25

本文关键词： 克里金插值法动态热定值蒙特卡罗方法线路分段　出处：《山东大学》2017年硕士论文　论文类型：学位论文

【摘要】：目前随着经济社会的飞速发展,社会用电量不断增加,输电线路是电力系统的重要组成部分,由于受到现有输电线路技术规程的制约,输电线路的传输容量受到了限制。提高电力系统的输配电容量可架设新的输电线路,但输电线路的建设耗资巨大且建设周期较长,因此如何更好地发挥现有输电元件的输电能力一直是电力部门十分关注的问题。首先,输电线路的热载荷能力与实时环境参数有关,影响输电线路热载荷能力的主要环境参数,如温度、风速、风向等可由环境测量装置测得,考虑到环境参数及架空输电线路的空间分布特性,及环境测量装置的有限性,本文首先研究对输电线路周围环境参数的估计方法,依据最常见的反距离插值法(Inverse Distance Weighted,IDW)以及广泛应用的普通克里金(Ordinary Kriging,OK)插值法,实现架空输电线路沿线无测量装置处环境参数的估计。实现架空输电线路热载流能力的分布热定值,不但减少投资成本,而且提高了线路载流定值的准确性,具有一定的理论与实用价值。其次,本文对输电线路热载荷能力的求解方法进行研究,包括线路的静态热定值(Static Thermal Rating,STR)以及动态热定值(Dynamic Thermal Rating,DTR),将由上述插值法得到的环境参数运用到输电线路动态热定值的求解中。由于获得的环境参数具有不确定性,本文基于蒙特卡罗方法对环境参数的不确定度进行研究,利用输电线路的热平衡方程,依据IEEE标准和CIGRE标准建立输电线路载流量的计算模型并进行不确定度分析。最后,由于线路温度对输电线路阻抗有影响,对于远距离的输电线路而言温度对阻抗的影响不可忽略。本文假设输电线路沿线温度与环境温度无限接近,研究温度对线路参数的影响,依据线路沿线温度分布情况对其分段,研究远距离输电线路的分段方法,并实现输电线路分段热定值。依据陕西电网地理接线图,选取从榆横到信义距离为386.7km,电压等级为750kV的架空输电线路,研究单机-单负荷系统的线路在不同温度下对应负荷的PV曲线特性。研究架空输电线路沿线温度的分布特性对系统运行状态的影响。本文利用插值方法实现了空间上环境参数的估计,通过蒙特卡罗方法评定不确定度,以及给出了基于温度的输电线路分段方法,可以有效提高线路的传输容量,挖掘电网输电能力。
[Abstract]:At present, with the rapid development of economy and society, social electricity consumption is increasing. Transmission line is an important part of power system, which is restricted by the existing transmission line technical regulations. The transmission capacity of transmission lines is limited. New transmission lines can be set up by increasing the transmission and distribution capacity of power systems, but the construction of transmission lines is expensive and has a long construction period. Therefore, how to make better use of the transmission capacity of existing transmission elements has been a problem of great concern in the power sector. Firstly, the thermal load capacity of transmission lines is related to real-time environmental parameters. The main environmental parameters, such as temperature, wind speed and wind direction, which affect the thermal load capacity of transmission lines, can be measured by the environmental measurement device, taking into account the environmental parameters and the spatial distribution characteristics of overhead transmission lines. And the limitation of the environmental measurement device, this paper first studies the method of estimating the environmental parameters around the transmission line. Inverse Distance Weighted is based on the most common inverse distance interpolation method. IDW) and the widely used ordinary Kriging KrigingOK interpolation method. To realize the estimation of environmental parameters without measuring devices along overhead transmission lines, and to realize the distribution caloric value of heat load capacity of overhead transmission lines, not only reduce the cost of investment, but also improve the accuracy of line current setting. It has certain theoretical and practical value. Secondly, this paper studies the method to solve the thermal load capacity of transmission lines. It includes static Thermal dating and dynamic Thermal Rating. The environmental parameters obtained from the above interpolation method are applied to the solution of the dynamic caloric value of the transmission line. The obtained environmental parameters are uncertain. In this paper, the uncertainty of environmental parameters is studied based on Monte Carlo method, and the heat balance equation of transmission line is used. According to IEEE standard and CIGRE standard, the calculation model of transmission line carrier current is established and the uncertainty is analyzed. Finally, because of the influence of line temperature on transmission line impedance. For long-distance transmission lines, the influence of temperature on the impedance can not be ignored. This paper assumes that the temperature along the transmission line is infinitely close to the ambient temperature, and studies the influence of temperature on the line parameters. According to the temperature distribution along the line, this paper studies the segmentation method of long-distance transmission line, and realizes the segmental calorific value of transmission line. An overhead transmission line with a distance of 386.7 km and a voltage grade of 750 kV is selected. The PV curve characteristics of the line corresponding to the load at different temperatures are studied. The influence of the temperature distribution along the overhead transmission line on the operating state of the system is studied. In this paper, the interpolation method is used to realize the performance of the system. The estimation of environmental parameters in space. The uncertainty is evaluated by Monte Carlo method, and the temperature based transmission line segmentation method is given, which can effectively improve the transmission capacity of the transmission line and excavate the transmission capacity of the power grid.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM75

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