高压直流输电线路合成电场及无线电干扰正逆问题研究

发布时间：2018-01-12 13:28

本文关键词：高压直流输电线路合成电场及无线电干扰正逆问题研究　出处：《华南理工大学》2014年博士论文　论文类型：学位论文

【摘要】：高压直流输电技术是西电东送工程安全稳定、经济的工程技术，解决我国经济的高速发展与环境污染、资源分布不平衡间的矛盾。然而，高压直流输电线路环境效应越来越受到大众的关注，其合成电场及无线电干扰分布影响着直流工程的建设成本。目前大量研究工作依靠试验线段或电晕笼分析合成电场及无线电干扰特性。但缺乏实际线路合成电场及无线电干扰分布的特性分析，同时现有的EPRI等经验公式无法计算给定温度、湿度等环境参数的合成电场及无线电干扰分布。针对考虑温湿度及海拔高度影响下高压直流合成电场及无线电干扰分布理论计算及实验手段存在的技术瓶颈，开展了实际线路的现场测试，从合成电场及无线电干扰分布计算的正、逆问题及预测方法方面，深入研究了合成电场及无线电干扰分布计算的理论模型和方法，，研究内容覆盖了合成电场及无线电干扰的现场分布特性、正逆问题计算的数学模型、迭代算法及实例应用效果等方面，研究重点及取得的成果主要体现在以下几个方面：（1）开展了云广特高压直流线路负极半压、负极全压、正极半压和负极全压、不同月份双极全压下的合成电场及无线电干扰分布的现场测量，克服了试验线路或电晕笼分析合成电场及无线电干扰时地形、温湿度等环境因素过于理想化的问题。深入研究了不同运行方式下的分布特性，获得了合成电场及无线电干扰的现场分布规律。对比分析了现场测量值与规程推荐方法仿真值的误差，揭示了误差产生的原因是规程推荐方法忽略地形、温湿度等环境因素的影响，并为合成电场及无线电干扰分布正逆问题及预测方法的模型分析提供测试数据的基础。（2）针对现有解析法、有限元等数值方法求解直流输电线路合成电场分布时忽略导线电晕层及温湿度等环境因素的影响，结合电场泊松方程、离子流扩散方程及电流连续方程，详细推导了直流输电线路合成电场正问题电晕区和非电晕区的分域控制方程及边界条件，实现了计算新模型兼顾电晕层及温湿度等环境因素的影响。首次提出了电晕层方程求解的无网格通量校正运移的小波变换算法，通过实例仿真计算与对比分析，验证无网格通量校正运移的小波变换算法求解直流输电线路合成电场正问题具有良好的收敛性，解决了有限元法网格畸变引起的迭代发散问题，提高了计算精度且降低了计算存储量。（3）基于直流导线电晕模型提出了导线电晕电流计算的积分方法，实现了给定了温湿度、海拔高度下电晕电流的计算，克服了因电晕笼尺寸、环境参数等因素影响下测量激发函数计算电晕电流受限问题。首次提出了两相电源测量输电线路开路阻抗和短路阻抗计算直流双极模型的高频率参数形成导纳和阻抗矩阵的方法，解决了因大地电导率、集肤效应等因素影响下高频参数理论计算精度较低的问题。结合电晕电流、高频参数、相模变换和叠加原理，提出了给定环境参数下的无线电干扰的计算方法。搭建了等效直流输电线路1000km的模型验证了直流线路高频分布参数计算方法的有效性；通过对比分析负极全压、双极全压下无线电干扰仿真值与测量值的误差验证了计算方法精度的可靠性。（4）基于最小二乘原理首次建立了模拟电荷在现场测量值、导线表面电位及大地表面的电位误差优化函数，建立了高压直流输电线路合成电场及无线电干扰逆问题模型。提出了高压直流输电线路合成电场及无线电干扰逆问题求解的信赖域正则化方法和遗传算法，克服了求解步长大引起的计算误差增加的问题，优化了模拟电荷的空间位置，实现了求解步长的限制及方向的动态调整。通过负极全压、正极半压与负极全压、双极全压下的算例分析，验证了合成电场及无线电干扰逆问题求解算法具有良好的收敛性、稳定性及计算精度。（5）建立了模糊聚类算法选择待预测点环境相近样本的数学模型，首次提出了基于相近样本的最小二乘支持向量机的合成电场和无线电干扰分布预测方法，建立了粒子群算法优化最小二乘支持向量机的惩罚系数和尺度因子的方法，提高了合成电场和无线电干扰分布计算的效率。并通过对比分析了不同运行方式、海拔高度下合成电场及无线电干扰的计算结果，验证了该方法提高了计算精度。
[Abstract]:HVDC technology is the electric power engineering safety and stability, economic engineering technology, to solve China's rapid economic development and environmental pollution, the contradiction between the uneven distribution of resources. However, the environmental effects of HVDC transmission lines more and more attention, the distribution of electric field and radio interference of HVDC project the cost of construction. A lot of research work on the test line or corona cage analysis of synthetic electric field and radio interference characteristics at present. But the lack of analysis of the actual circuit synthesis of electric field and radio interference distribution characteristics at the same time, the existing EPRI empirical formula to compute the given temperature, electric field and radio interference distribution of humidity and other environmental parameters.
Aiming at the technical difficulties of considering temperature and humidity and altitude under the influence of high voltage DC electric field and radio interference of the distribution of the theoretical calculation and experimental means, carry out the actual test line, from the synthesis of electrical field and radio interference in distributed computing, inverse problem and prediction methods, in-depth study of the theoretical model and method for the synthesis of electric field and radio the interference of distributed computing, the research content covers the synthesis of electric field and radio interference characteristics, the mathematical model of forward and inverse problem calculation, iterative algorithms and examples of application, research and achievements are mainly embodied in the following aspects:
(1) the development of Yun Guang UHVDC negative half pressure, negative pressure, positive pressure and negative pressure half full, measuring total pressure under the electric field and radio interference field distribution in different months bipolar, overcome the test line or corona cage analysis synthesis electric field and radio interference when the terrain, temperature and humidity etc. environmental factors too idealistic. In depth distribution characteristics under different operating modes of the study, obtained on-site synthesis of electrical field and radio interference distribution. Comparison and analysis of the on-site measurement error of simulation value and the procedures recommended, exposing the reason shows that errors are recommended in the standard method ignores the terrain, the influence of temperature and humidity etc. the environmental factors, and for the synthesis of electric field and radio interference distribution is inverse problem and forecasting model to provide the basic analysis of test data.
(2) according to the existing analytical method, neglecting the effect of corona layer temperature and humidity and other environmental factors such as finite element numerical method for DC transmission line composite electric field distribution, combined with field Poisson equation, ion diffusion equation and current continuity equation, deduced the equations and the boundary conditions of the sub domain electric field of HVDC transmission lines is the problem the corona and non corona zone control, realize the new model to calculate the influence of both the corona layer and environmental factors such as temperature and humidity. For the first time put forward the algorithm of wavelet transform grid flux corrected transport corona layer equation, through calculation and analysis of simulation examples, verify the meshless flux corrected wavelet transform algorithm for solving DC migration transmission line electric field forward problem has good convergence, to solve the finite element mesh distortion problem caused by iterative divergence, improves the calculation accuracy and The amount of storage is reduced.
(3) DC corona model based on the integral calculation method of conductor corona current is proposed, realizing the given temperature and humidity, calculate the corona current altitude, avoid corona cage size, effects of environmental parameters measured under the excitation function to calculate the corona current limitation method is put forward for the first time. The high frequency parameters of two-phase power the measurement of transmission line open circuit impedance and short-circuit impedance calculation of DC bipolar model forming admittance and impedance matrix, solves the problem of the earth conductivity, the calculation precision of the problem of low frequency parameter theory of skin effect and other factors. Combined with the corona current, high frequency parameters, phase mode transformation and superposition principle, puts forward the calculation method of radio interference under the given environment parameters. Build the equivalent DC transmission line 1000km high frequency distribution model to verify the DC line parameter calculation method is effective; The reliability of the accuracy of the calculation method is verified by the comparison and analysis of the total pressure of the negative electrode and the error of the simulation value and the measured value of the radio interference under the bipolar full pressure.
(4) based on the principle of least squares is established for the first time in the field of charge simulation measurement, error optimization function of potential conductor surface potential and the surface of the earth, a synthesis of electric field of HVDC transmission lines and radio interference of the inverse problem of trust region model. The regularization method and the genetic algorithm was proposed for the synthesis of electric field of HVDC transmission lines and radio interference inverse problem for the increase of calculation error can solve the problems caused by the step up, to optimize the spatial position of charge simulation, achieve dynamic adjustment of limitation and direction for solving step. By negative pressure, positive pressure and negative pressure half full, the example analysis of bipolar full voltage, verified the synthesis of electric field and radio interference inverse problem solving algorithm has good convergence, stability and accuracy.
(5) established a fuzzy clustering algorithm to select model sample similar environment, first proposed the synthesis field least squares support vector machine is similar to the sample and radio interference distribution prediction method based on the established method of penalty coefficient and the scale factor of particle swarm optimization algorithm and least squares support vector machine, improve the efficiency of electric field and radio interference in distributed computing. And analyzes the different operating modes by comparing the calculation results, the synthesis of electric field and radio interference under high altitude, the validation of the method improves the calculation accuracy.

【学位授予单位】：华南理工大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM721.1;TN972

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