表面电荷法在复杂地势下超高压输电线路的工频电场计算

为了更准确地研究超高压输电线路穿越较复杂地区时的工频电场,利用表面电荷法的思想,给出了该方法的实施步骤并进行了验证。综合考虑了输电线路的弧垂,建立了复杂地势三角坡和凸面的三维模型,并仿真分析了其周围工频电场的分布。研究结果表明:1三角坡和凸面对输电线路下的工频电场影响较明显;2随着三角坡坡角的增大场强值畸变越大,且使临近三角坡坡脚处场强值减少越大;3不同的输电线排列方式下,复杂地势周围的工频电场畸变不同,倒三角排列下其值畸变大于其他排列。该仿真结果可为复杂地势下输电线路的架设提供参考依据。     

Prediction and improvement of the electric field distribution in high voltage AC substations

Various full-scale and model-scale measurements of electric field effects in several 330 and 500 kV AC substations are reviewed. Statistical analysis of the test results is recommended. The accuracy of model-scale measurements is satisfactory for engineering requirements. Model-scale measurements and analytical calculations of the electric field effects are analyzed and used in order to predict the electric field related performance of AC substations in the design phase.     

粒子群优化模拟电荷法在HGIS工频电场计算中的应用

近年来,复合型气体绝缘组合开关设备（HGIS）以其造价适中、占地面积小、运行安全可靠等优点,在我国超高压变电站建设中得到越来越多的应用。研究分析HGIS工频电场分布规律,对智能变电站设计与建设、电磁环境评估、消除民众对输变电工程电磁辐射不必要的担忧等有着重要的指导和现实意义。鉴于传统模拟电荷法（CSM）在布点和校验上过于繁琐,难以应对复杂计算场景的问题,本文提出将粒子群优化算法（PSO）和传统模拟电荷法结合,形成优化模拟电荷法（PSO-CSM）,并将其应用到500kV HGIS配电装置区工频电场的计算与分析中,计算分析配电装置区各主要设备对工频电场的影响以及整个配电装置区工频电场分布状况,并提出了电场优化的相关建议和改进措施。     

超高压输电线工频电场计算的矩量法和表面电荷混合法

结合矩量法和表面电荷法各自的优点,提出一种用矩量法—表面电荷法相结合的混合算法来计算复杂场景下超高压输电线工频电场的分布,通过综合考虑输电线路的弧垂、分裂导线等因素,建立了复杂场景下超高压输电线的三维模型,并进行了相应的计算。结果表明:该混合法具有提高计算速度,减少占用内存和避免模拟点电荷设置等优点。对于所述的树状物模型,树状物对其下方离地1.5 m处工频电场起屏蔽作用。树状物尺寸参数的变化对其下工频电场分布影响明显,树冠半径越大其屏蔽范围越大,树干高度越高其屏蔽强度越弱。相间距和输电线高度的变化对电场值基本无影响。混合法可为高压输电线路在复杂场景下工频电场分析提供重要的参考。     

Optimal planning of high voltage distribution substations

Aimed at solving the problem of optimal planning for high voltage distribution substations, an efficient method is put forward. The method divides the problem into two sub-problems: source locating and combinational optimization. The algorithm of allocating and locating alternatively (ALA) is widely used to deal with the source locating problem, but it is dependent on the initial location to a large degree. Thus, some modifications were made to the ALA algorithm, which could greatly improve the quality of solutions. In addition, considering the non-convex and non-concave nature of the sub-problem of combinational optimization, the branch-and-bound technique was adopted to obtain or approximate a global optimal solution. To improve the efficiency of the branch-and-bound technique, some heuristic principles were proposed to cut those branches that may generate a global optimization solution with low probability. Examples show that the proposed algorithm meets the requirement of engineering and it is an effective approach to rapidly solve the problem of optimal planning for high voltage distribution substations. Translated from Journal of Tianjin University, 2006, 39(8): 889–894 [译自: 天津大学学报]     

基于模拟电荷法的变电站工频电场仿真分析

随着供电需求的增大,超高压变电站越来越接近公众活动区域,变电站站内的电场分布情况也显得越来越重要。本文提出改进的模拟电荷法,推导了带电体周围的工频电场计算公式。通过对500k V变电站进行模型建立及简化,编程计算出站内离地1.5m处的工频电场强度;采用CDEGS软件对重庆某500k V变电站进行仿真计算,将仿真结果和实测值与本文算法的计算结果进行对比,验证了本文算法的正确性与有效性。最后选取该变电站内三条路径,计算分析该处工频电场强度的分布情况,为深入研究变电站的工频电场分布提供参考。     

Electric field calculation in composite dielectrics by surface charge method based on electric flux continuity condition

We propose a new surface charge method based on the continuity of electric flux passing through each partial area on the dielectric boundary. N partial areas divided on the boundary give the boundary equations for solving N unknown variables representing the surface charge density distribution. The electric flux is numerically calculated by integrating the normal component of electric flux density on each partial area. This method permits us to exclude the singularity of edge parts from the boundary equations because these parts do not contribute to the integration area. In this paper, we apply first‐order functions to simulate both triangular surface shape and charge density distribution on its surface as well. First, we have computed the electric field for a spherical dielectric under a uniform field. The calculated results show that the accuracy of the electric field at the spherical center is almost equal to the accuracy of the total surface area of the polygon which represents the sphere. Furthermore, this method has improved the accuracy of the field by about one order compared with the conventional surface charge methods. Second, we have computed the electric field for a dielectric human model under a uniform field. The calculated results demonstrates that the proposed method works well for a complicated shaped object with a dielectric constant greatly different from that of an ambient medium. © 2002 Scripta Technica, Electr Eng Jpn, 138(4): 10–17, 2002; DOI 10.1002/eej.1133     

An efficient method for calculation of electric field in three-corepower cables

In this paper we applied the superposition principle with a new basic conductor voltage condition for the computed electric field in three-core cables and the results obtained have higher accuracy and lower computational time than the previous works. The maximum potential error is not more than 0.050% and the maximum field deviation angle is not more than 0.011°. The electric field problem under arbitrary conductor voltage condition is reduced to a field computation for a new basic conductor voltage condition (0,1,-1) which reduces the computing time because it doesn't require the repetitive solution of the algorithm for different ωt values. With this new configuration, it is possible to take advantages of a symmetrical conductor arrangement reducing the number of charges necessary for the field calculation and the superposition principle is applied only two times     

多路供电系统高压输电线下工频电场的广义数学模型

在电磁环境保护和ADSS光缆悬挂设计时，都需要计算出空间任意点的最大场强值。由于输电线的交流电压随时间而变化，所以空间点的场强也随时间而变化，但在各线布局和电压等级一定的情况下，各点的最大场强值是固定的。为了准确计算多路供电系统高压输电线下空间点的最大场强值，采用等效电荷法，分别基于频域和时域建立了其广义数学模型，并推导出了最大场强计算公式。通过比较发现时域方法占用内存较少且延拓性较强，建议采用时域方法。通过编程对一条同杆塔双回输电线路进行了计算，其结果和理论分析结果一致。     

Development of three-dimensional electric field analysis by segment arrangement based on a charge simulation method

This paper describes the development of three-dimensional electric field analysis by using the so-called segment method which enables the electric field to be calculated with high accuracy and with enhanced efficiency, for high-voltage apparatus. In the segment method, electrode configuration of high-voltage apparatus is simulated by small components which are called segments and by the arrangement of several kinds of such segments. In this calculation, the charge simulation method is used which is suitable for segment application. As basic segments, spherical, cylindrical and ring segments are used and in addition to these, as subsegments, disc and elbow segments are adopted for good simulation of the total electrode configuration. In this paper, the fundamental construction and arrangement parameter of segments were discussed. Moreover, the segment method was applied to an actual high-voltage apparatus and the calculation accuracy was discussed. It was clarified that the segment method has sufficient calculation accuracy and is a very efficient means for three-dimensional electric field analysis.     

脉冲电场灭菌用固态高压开关的研制

针对脉冲电场灭菌技术对开关性能的特殊要求,提出了利用IGBT串联构成高压、大容量固态开关的技术。设计并实际制造出了可供高压脉冲电场灭菌用额定电压10 k V的固态高压开关。该开关采用8个1 700 V、400 A的IGBT串联,以栅极动态RCD为基本均压方式,以FPGA为主控单元,产生8路相对独立的基准控制脉冲,其脉宽、周期、延时均可调节,且以25 ns为步进调节。通过调节各路驱动信号的相对延时,使各单元分压均匀,消除过压影响,从而在负载端得到较为理想的方波脉冲。采用光纤隔离,使隔离电压不受限制。实验结果表明,该装置性能良好,可以满足脉冲电场灭菌的实际需求。     

三维表面电荷法在位场计算中的几点改进

针对常规三维表面电荷法在位场计算中采用平面单元剖分、常值电荷估计致使计算效率低内存消耗大的缺点,对表面电荷法进行改进。采用曲面三角形单元对曲面进行剖分并通过二次多项式进行插值,利用线性或二次插值估计电荷密度以反映电极表面电荷密度的线性及非线性分布的特点,在奇异积分处理上通过切平面法解决格林函数基本解的奇异积分,并给出其具体实现。最后通过两个典型算例进行了验证,结果表明该方法精度较高,具有一定可行性。     

Design optimization of high voltage bushing using electric field computations

This paper illustrates the use of electric field computation to optimize the design of gas filled high voltage composite bushings. The United States Navy employs these bushings in high power very low frequency/low frequency transmitting stations. Commercially available 2D and 3D computational packages based on the boundary element method were employed to analyze the electric fields. The optimized design uses both internal and external elements for electric stress grading at critical parts of the bushing. It has been shown that the location and magnitude of the maximum electric field have been optimized which should result in a substantially higher corona free operating voltage     

基于表面电荷法的输电线路表面电场强度计算

三相输电线路导线表面电荷的分布是不均匀的,各点电场强度的大小也不同.文中采用表面电荷法计算导线表面的电荷密度,然后求出导线表面各点的最大电场强度值.计算方法能够反映出电荷密度及电场强度沿导线圆周分布的情况,根据计算结果优化高压输电线路的布置.     

应用非稳态开路电压方法估计EV用电池剩余电量研究

针对稳态开路电压方法预测电动车用电池剩余容量需很长时间的缺点,提出一种新型的基于电池等效电路模型的非稳态开路电压方法,实现快速估计电池的剩余容量,根据电池当前的非稳态开路电压及其电池停歇时间和辨识出的电池参数,估计电池的剩余容量。比较电池放电停歇阶段真实的剩余电量数据和非稳态开路电压方法估计出的剩余电量数据,证明该方法精确度较高,有较强的实用性。     

Evaluation method of computational error for electric field analysis by a surface charge method

In this paper, an evaluation method of computational error for the electric field analysis by a surface charge method is proposed. In the method, an approximate equation of the smoothness of the electric field distribution is used to evaluate the computational error. In two‐dimensional and axisymmetric problems, the approximate equation of the smoothness is expressed by the second derivative form of the surface charge density with respect to the distance along the surface. Furthermore, the smoothness is expanded to three‐dimensional problems and a general form of the equation for the smoothness is obtained. The applicability of the proposed method is verified by computation results of a two‐sphere model and a hyperboloid model. © 1998 Scripta Technica, Electr Eng Jpn, 126(1): 7–14, 1999     

现有超高压变电站高型构架的改造

以水泥支柱和钢铁构件为主的户外高型构架配电装置是城市超高压变电站一种典型的、普遍的布置方式。这些变电站的高型构架经日晒雨淋 ,运行迄今已经接近设计使用的年限。虽经多次改造、整修 ,但并没有从根本上消除高型构架的缺陷 ,如水泥支柱已经老化剥落 ,某些关键金属部件已严重锈蚀 ,给电网的安全、可靠运行带来很大的隐患 ;此外 ,由于地基的沉降 ,有些高型构架出现了轻度的倾斜。随着城市的建设和发展 ,大部分变电站的周边被新的城区所包围 ,已经老化和锈蚀的高型构架装置与周边的环境也极不协调。这样 ,电力部门面临着两难的境地 :一方…     

跨越建筑物的高压输电线三维电场仿真

传统的二维模型已不能正确描述输电线下存在建筑物时高压线下工频电场分布,提出了采用模拟电荷法,综合考虑线路弧垂,建立有建筑物时工频电场的三维数学模型,对电场进行仿真,给出仿真结果,与没有建筑物时比较,有建筑物时电场分布更加复杂,并产生畸变点.最后按此模型采用目前流行的VC和Matlab混合编程的方式编制了仿真软件.