1100 kV GIS设备主回路绝缘试验电气参量估算方法研究

为了实现1100 kV气体绝缘组合电器(GIS)主回路绝缘试验的分段、设备选择以及参数匹配的合理性,提出一种电气参量估算方法。首先,概述主回路绝缘试验方法,阐述试验原理和加压程序。然后,综合考虑试验频率和设备容量等限制条件,提出了有无并联补偿两种情况下变频串联谐振装置试验能力的估算方法。接着,提出了指定试验范围时特高压GIS主回路绝缘试验电气参量的估算方法。最后,以某特高压GIS主回路绝缘试验为例,估算变频串联谐振装置的试验能力,验证指定试验范围时电气参量估算方法的准确性。该估算方法能够准确地评估变频串联谐振装置的试验能力,实现指定试验范围时电气参量的准确估算,为特高压GIS主回路绝缘试验的分段和设备选择提供了可靠的参考。     

1100 kV GIS隔离开关的电场数值计算与分析

为了解特高压GIS隔离开关气室内部的电场强度分布情况,建立了两种典型结构的1100kV GIS隔离开关气室三维静电场数学模型。基于电场数值分析理论,采用有限元分析方法实现了大型实际工程电磁场问题的三维电场精确计算。对隔离开关的气室进行详细电场计算的结果表明,接地开关触头间隙是场强集中的区域,盆式绝缘子的结构尺寸的合理设计可以有效改善电极屏蔽罩区域的电场分布。对比两种隔离开关的电场强度分布结果可知,2种不同结构的对应区域场强最大值以及电场分布稍有差异,但都具有一定的绝缘裕度。电场分析所得的结果,为特高压隔离开关气室的整体和内部结构的进一步优化设计提供了理论依据。     

Structural optimization of grading rings on composite insulators on 500‐kV compact transmission lines

Serious corona discharges occur on some grading rings of 500‐kV compact transmission lines in China owing to defects in the structural design. The noise of the corona is heard clearly even 50 m away from the tower. In order to solve this problem, we have optimized the structure of the grading rings to suppress the corona. In this study, the grading rings that had serious corona discharges were identified and observed with an ultraviolet imager (UVI), and the electric field (E‐field) distributions of the grading rings were calculated by means of the three‐dimensional finite element method. Based on an analysis of the areas on the grading ring where excessive high E‐field magnitudes were observed, we optimized the structures of the grading rings to improve the field distributions on their surfaces. Based on the optimization suggestions, new grading rings were manufactured to replace the old ones. UVI observations showed that the new grading rings could effectively prevent the occurrence of corona discharge. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Development of 72‐kV high‐pressure air‐insulated GIS with vacuum circuit breaker

SF₆ gas has excellent dielectric strength and interruption performance. For these reasons, it has been widely used for gas‐insulated switchgear (GIS). However, use of SF₆ gas has become regulated under agreements set at the 1997 COP3. Thus, investigation and development for GIS with a lower amount of SF₆ gas are being carried out worldwide. Presently, SF₆‐free GIS has been commercialized for the 24‐kV class. Air or N₂ gas is used as the insulation gas for this GIS. On the other hand, SF₆‐free GIS has not been commercialized for the 72‐kV‐class GIS. The dielectric strengths of air and N₂ gas are approximately one‐third that of SF₆ gas. To enhance the insulation performance of air and N₂ we have investigated a hybrid gas insulation system which has the combined features of providing an insulation coating and suitable insulation gas. We have developed the world's first 72‐kV SF₆‐free GIS. This paper deals with key technologies for SF₆‐free GIS, such as the hybrid insulation structure, a bellows for the high‐pressure vacuum circuit breaker, a newly designed disconnector and spacer, and prevention of particle levitation. Test results of the 72‐kV high‐pressure air‐insulated GIS with the vacuum circuit breaker are described. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 157(4): 13–23, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20451     

基于区域分解法的1100kV隔离开关大规模电场计算问题

大规模电磁场求解计算时,通常采用有限元法会面临计算与存储量庞大、求解效率较低的问题,为此考虑采用区域分解法来解决.笔者在阐述区域分解法求解原理后,建立了特高压隔离开关气室三维电场问题模型,并将计算结果与整体法所求结果进行比较,结果表明,采用区域分解法有效缓解了存储空间限制、提高了求解效率.同时采用基于参数化设计语言(A...     

Robustness of the multigrid method for edge‐based finite element analysis

The dependence of the multigrid finite element method solving three‐dimensional magnetostatic fields on the quality of the finite element mesh is reported. It is shown that the convergence of the multigrid method is strongly influenced by the mesh quality. Moreover, the multigrid method with ICCG smoother is shown to be more robust against mesh distortion than that with Gauss–Seidel and SOR smoothers. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 148(1): 75–81, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10289     

800kVGIS隔离开关磁场-温度场计算与分析

800kV GIS隔离开关在实际运行中由于电阻损耗发热而温度升高,甚至超过允许温升,从而影响其工作性能,为了保证其工作的安全性和可靠性,建立了三维有限元分析模型对800kV GIS隔离开关的工频磁场进行分析。首先计算出隔离开关上的磁感应强度分布及涡流损耗,然后将涡流损耗值作为体积热源计算800kVGIS隔离开关的温度场,得出各部分具体温升值。结果表明:在环境温度为27.3°C的工作条件下,隔离开关主导体上的温升约为26.3K,外壳温升约为13.3K。计算结果和试验测试数据的对比验证了方法的准确性,进而为产品设计提供参考,为提高GIS隔离开关运行可靠性提供理论依据。     

330kV线路用FR型防振锤结构优化

330kV输电线路所采用的FR-3型防振锤结构复杂,其锤头形似音又,两端面的曲率半径较小,导致其场强较高,在实际运行中可能会发生电晕放电,从而对周围的电磁环境造成污染。采用有限元方法建立FR．3型防振锤的三维模型进行电场仿真计算,得出了防振锤的电场分布规律,据此优化了其锤头的音叉结构,将锤头端部的最高场强由3000kV...     

An Imanishism‐based genetic algorithm for sampling various Pareto‐optimal solutions: An application to the multiobjective resource division problem

For sampling various solutions from the entire Pareto front of the multiobjective resource division problem, a new Genetic Algorithm (GA) based on an evolutionary theory advocated by Kinji Imanishi is proposed. First, two types of distance between two individuals, namely, structural and functional distances, are introduced and used to define four types of relation between them, namely, homogeneous, heterogeneous, homologous, and analogous species. Then, for keeping a variety of species within a population as far as possible, a new generation alternation model with variable population size is presented. In order to find Pareto‐optimal solutions effectively, a new genetic operation that combines conventional harmonic crossover with a local optimization algorithm is also proposed. Finally, the advantage of the Imanishism‐based GA is demonstrated through computational experiments conducted on two‐ and three‐objective problem instances. © 2002 Scripta Technica, Electr Eng Jpn, 139(2): 23–35, 2002; DOI 10.1002/eej.10010     

Results of lightning impulse tests for a 275‐kV full GIS substation

This paper describes the outline and results of the lightning impulse tests for a 275‐kV full GIS substation. The behavior of lightning surges is a very important factor for the rational design of substations and low‐voltage and control circuits inside the substations. For the above reason, we carried out lightning impulse tests for a new 275‐kV full GIS substation. In these tests, we measured voltage induced in low‐voltage and control circuits, transient characteristics of grounding grid, injected voltage and current waveforms, and so on. By investigating these data, we confirmed the behavior of lightning surges inside the substation. We also compared simulated waveforms by EMTP analysis with the measured waveforms. The simulated results agreed well with the measured results. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 146(1): 46–58, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10230     

Analysis of the insulation structure and electrical distribution of 1100‐kV OIP condenser transformer bushings in China

In this paper, the technical parameters, main dimensions, structural design, and the electrical field distribution of a 1100‐kV AC oil‐impregnated paper (OIP) condenser transformer bushing used in the Wuhan (China) ultrahigh‐voltage (UHV) experiment are presented. The electrical field calculations of the bushing, which is composed of the condenser, the lower porcelain housing, the grading ball, the transformer lifting seat, and the insulated oil, are performed and the parameters of the grading rings are optimized. The electrical field distribution curves of the bushing at 1.5 m height to ground are also drawn. By studying and experimenting on the 1100‐kV bushing, the inner and the outer insulation structure of the bushing were found to be proper; the radial and the axial electrical fields meet the design requirement; the performance parameters of the bushing are in accord with the corresponding standards and technical specifications. The bushing has already passed the type tests and works well at the Wuhan UHV AC experimental base. This establishes a good foundation for the design, manufacture, and experimentation on the 1100‐kV AC OIP condenser transformer bushing. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

基于粒子群算法的直线振动发电机优化设计

设计了一种新型圆筒式永磁直线振动发电机,电机中永磁体放置在绕组外侧,内部通过放置铁心来增大感应电动势的幅值。其结构简单,尺寸多变,可将原来损失的小幅振动能量转化为电能,为小型设备提供低压直流。通过二维有限元对其非线性无边界轴对称磁场进行了系统的分析,得到一系列电机感应电动势与电机尺寸间的变化规律,并以有限元分析结果为基础,结合粒子群优化算法,归纳出通用的优化设计准则和公式。优化结果表明,为了得到更高的材料利用率,应取较大的永磁体外径,且样机实验和有限元分析结果吻合良好。     

基于有限元方法500kV交流输电线路表面电场强度的研究

本文基于有限元方法详细讨论了500 kV交流输电线路导线表面电场的分布规律,并定量分析了线路参数及导线表面特性对导线表面最大电场强度的影响.结果表明,线路采用多分裂、大截面、倒三角布置方式,可以降低导线表面电场强度;不光滑导线将导致导线表面电场增大.     

Magnet shape optimization of five‐phase surface‐mounted permanent magnet machine to improve torque performance based on equivalent permanent magnet method

This paper studies the magnet shape optimization of a five‐phase surface‐mounted permanent magnet (PM) machine to improve its torque performance. First, a sinusoidal PM with third and fifth harmonics (sine + third + fifth PM) is presented to enhance the torque. An equivalent PM method is then proposed to avoid the complicated interface conditions between PM and the air gap, making the derivation of torques with magnet shapes using 2‐D analytical models possible. Besides, the influence of PM edge thickness on torque improvement is considered. Moreover, under the condition that the copper losses of machines with different magnet shapes are kept unchanged, optimal harmonics of sinusoidal PM with third harmonic (sine + third PM) and sine + third + fifth PM are analytically derived. Finite element (FE) analysis is performed to validate the equivalent PM method and analytical results. Finally, machines with sine + third PM, sine + third + fifth PM and conventional (without shaping) PM are comparatively studied using nonlinear FE analysis and the experimental results of machine with sine + third + fifth PM are presented, verifying the effectiveness of the analytical optimization of magnet shape. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

±800 kV柔性直流换流阀阀塔均压优化设计

柔性直流输电工程已迈入特高压时代,现有柔性直流换流阀(VSC阀)的均压屏蔽设计已无法满足特高压应用场合。为解决±800 kV VSC阀塔顶部均压管母表面电场强度过大的问题,文中首先利用PTC Creo与ANSYS联合建模技术完成复杂阀塔结构的三维建模与静电场有限元仿真,通过增加与顶部均压管母等电位连接的顶部屏蔽板,有效降低阀塔顶部均压管母及子模块的表面电场强度。然后,提取顶部屏蔽板增加前后的阀塔对地寄生电容参数,分析顶部屏蔽板对操作冲击下模块电压分布的影响。最后,研究阀塔不同均压部件间距对最大电场强度分布的影响,完成±800 kV VSC阀塔均压优化设计,并在阀塔样机上进行冲击电压试验。文中所提优化措施提升了VSC阀在特高压应用场景的安全运行能力,为VSC阀在特高压柔性直流输电工程的应用及设计提供借鉴。     

Voltage distribution analysis and grading ring design for porcelain insulators on 750‐kV compact transmission lines

On a compact transmission line, there are three phases arranged in one tower window. They form an inverted triangle with a small air gap, having no shielding between each other. This characteristic results in mutual effects among the three phases, which cause higher voltages and electric field intensities on the porcelain insulators and fittings than the ordinary lines. In this paper, a three‐dimensional finite element method (FEM) is presented to calculate the potential and electric field distributions of the porcelain insulators on a 750‐kV compact double‐circuit transmission line. Considering the mutual effects among the three phases, the structural parameters of the grading ring are optimized to reduce the voltages and electric field intensities on the insulators. The results show that the significant mutual effects among the three phases need to be taken into account in the design and testing of the insulators and fittings. In addition, structural parameters of the optimized grading ring are proposed on the basis of the above‐mentioned analysis. The comparison between the numerical calculations and the test results shows the accuracy of the FEM. Thus, in the approval test, it might be more reasonable and efficient to determine the correction factors through analyzing the calculations of the actual line and test arrangement. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

1000kV特高压交流复合绝缘子耐张串均压特性研究

交流电压作用下,由于复合绝缘子导线侧和杆塔侧的杂散电容不同,绝缘子的沿串电压分布不均匀。采用三维有限元方法分别计算了特高压交流1 000 kV单回和双回输电线路一字型4联550 kN复合绝缘子耐张串的沿面电位和电场分布,比较了大环屏蔽深度、管径、外径等均压环结构参数对电场分布的影响,给出了均压环的推荐配置方案。结果表明,当中相施加相电压峰值时,各关键部位场强值最大;单回和双回耐张串均压环表面最大场强分别为2.06 kV/mm和1.8 kV/mm,绝缘子伞裙护套表面最大场强分别为0.33 kV/mm和0.31 kV/mm,满足均压环表面场强在峰值下不超过2 kV/mm,复合绝缘子伞裙护套表面场强在有效值下不超过0.4 kV/mm的电场控制要求。     

基于模糊推理田口法的IPMSM多目标优化设计

内置式永磁同步电机（IPMSM）已广泛应用在电动汽车、城市轨道交通等领域,高转矩密度、宽调速范围和低振动噪声等是IPMSM设计时需要兼顾的重要性能指标。提出基于模糊推理田口法的IPMSM多目标优化设计,以解决平均转矩、转矩脉动和弱磁扩速范围多个优化目标之间的制约和冲突问题。在田口正交实验设计的基础上,利用模糊推理将多个优化目标转化为单一目标,从而获得电机的最优设计参数组合。有限元仿真表明,所提出的优化设计方案与优化前和传统田口法比较,各性能指标均得到较大的提升,验证了模糊推理田口法的有效性和先进性。     

适用于大规模系统的两阶段机组组合优化方法

提出一种两阶段优化方法以简单、快速、有效地求解大规模系统的机组组合问题。首先,针对传统PL法排序指标单一,不能全面评价机组运行费用的不足,引入可调发电机组煤耗、机组最大出力、机组启动成本三个指标,全面反映发电机组的经济性;其次,不同于传统PL法先安排机组启停满足旋转备用,再调整机组状态满足最小启停时间,同时考虑这两个约束,以更好地实现优先开启运行费用较小的机组;最后,在经济调度阶段提出一种考虑机组爬坡率的功率平衡调整策略,保证粒子的多样性的同时避免快速收敛到局部最优解,提高最终解的质量。将所提方法应用于10机组、20机组、40机组、60机组80机组以及100机组24时段6个系统进行测试,并与其它方法进行对比,数值结果表明,所提两阶段优化方法计算快速、收敛性良好、能够有效解决大规模系统机组组合问题。     

Adaptive finite element method for shape modification in optimization of electric machines

A method for the modification of finite element meshes based on adaptive meshing for optimization of electric machines is proposed. In the optimization of the machine, the proposed method generates the mesh for the new shape from the previous mesh with minor modification. The locations of the nodes for the new shape are decided by solving a Laplacian equation whose unknowns are the displacements of the nodes. The advantages are illustrated by application to the shape optimization of an IPM motor. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 168(1): 21–28, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20773