工频电磁环境条件约束下的超/特高压输电线路结构布局寻优方法

Optimization Algorithm for Arranging Extra-and Ultra-High Voltage Transmission Lines Subjected to the Constraints of Power Frequency Electromagnetic Environment Condition

为使新建输电线路下方的工频电磁环境最优或者满足预设要求,促进"绿色和谐"超/特高压电网的发展,提出了一种基于改进型粒子群算法的线路结构设计优化策略。该优化策略中有4个关键点需要特别指出。其一,利用线路下方某区域中的工频电场强度和磁感应强度、以及其它相关影响因素构建适应度函数。其二,根据线路绝缘要求设置相导线空间位置的约束条件。其三,根据电磁环保要求设置终止条件。其四,采用自适应调整惯性权重技术改善粒子群算法的性能。通过迭代搜寻适应度函数全局最优解从而确定传输线的最优结构位置。对500 k V紧凑型线路、1 000 k V特高压线路交叉跨越500 k V线路两个算例进行了仿真分析,验证了该方法的有效性。研究结果表明所提出的方法适用于各种高压输电线路结构,具有全局搜索能力强、收敛速度快、精度高等优点。

In order to minimize the power frequency electromagnetic environment under the pre-built high voltage （HV） transmission lines （TLs） or meet its preset requirement, and then contribute to the development of green and harmonious extra- and ultra-HV grid in China, a methodology based on improved particle swarm optimization （IPSO） algorithm is proposed in this paper to optimize the design of TLs＇ structural layout. Four key points are pointed out for special mention in the present methodology. First, a fitness function is constructed by taking account of the power frequency electric field strength and magnetic flux density generated by TLs, and other relevant influential factors. Secondly, the constraint conditions on the spatial positions of the phase conductors are put forward according to the insulation safety requirements. Thirdly, the termination conditions are put forward based on the requirements of the environmental protection. Fourthly, the technique of adaptive adjustable inertia weight parameter is adopted to improve the performance of PSO algorithm. The optimal structure layout of TLs finally is determined by the iterative search for the global optimum solution of the fitness function. Two simulation cases are carried out, in which one is related to 500kV compact TLs and another is related to 1 000 kV TLs crossing over existing 500 kV TLs. The effectiveness of the optimization algorithm is verified. The simulation results show that the proposed method is effective to all kinds of configuration of HV TLs. It also has the advantages of higher global searching ability, convergence speed and computational accuracy.