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WEI Y F, ZOU J K, WANG P,et al.New power flow method for flexible DC systems based on seventh-order NR method and Broyden method[J].Journal of Henan Polytechnic University(Natural Science) ,2024,43(4):141-151.

基于七阶NR法与Broyden方法的柔性直流系统潮流新算法

韦延方1,2, 邹建凯1,3, 王鹏4, 曾志辉1

1.河南理工大学 电气工程与自动化学院，河南 焦作  454000;2.河南省煤矿装备智能检测与控制重点实验室，河南 焦作  454000;3.国网安阳供电公司，河南 安阳  455000;4.国网河南省电力公司 电力科学研究院，河南 郑州  450052

摘要: 目的 为了解决当前柔性直流输电系统潮流算法求解效率低的问题，方法 首先提出基于七阶NR法的潮流算法，该算法相较于传统的潮流算法具有更高的收敛阶数，可以有效减少迭代次数，提高算法效率；其次，针对七阶NR法单步迭代计算量大的问题，提出基于七阶NR法与Broyden方法的改进算法，利用七阶NR法突出的收敛特性，减少迭代次数，同时保留Broyden方法单步迭代计算成本较低的优势，避免浪费计算能力，使计算效率得到较大提升；最后提出一种经验法则，以确定改进算法中高阶NR法的迭代次数。结果 使用经典和改进算法对修改后的IEEE标准算例进行仿真测试，结果表明：与经典NR法相比，交流和直流的改进算法潮流计算结果最大误差分别为1×10^-8和2×10^-8；平均计算时间方面，在IEEE-14、IEEE-30、IEEE-57、IEEE-118共4种算例系统下，改进算法的平均计算时间比经典NR法的减少了约61%；当算例系统由双端变为三端和双馈入后，改进算法的迭代次数保持不变，计算时间分别增加0.352 ms和0.636 ms；在重负荷情况下，改进算法的计算效率最高，且预设迭代次数较简单，当负荷值达到2.992时，其计算时间仅为经典NR法的60%。结论 本文的改进算法具有与经典NR法相同的精确性，但在计算速度方面更有优势，且更有利于在重负荷等极端情况下使用。

关键词:电压源换流器;高压直流输电;七阶NR法;Broyden方法;潮流计算

doi:10.16186/j.cnki.1673-9787.2022030044

基金项目:国家自然科学基金资助项目（61703144）；海南省自然科学基金资助项目（521RC1110）

收稿日期:2022/03/16

修回日期:2023/04/11

出版日期:2024/07/15

New power flow method for flexible DC systems based on seventh-order NR method and Broyden method

WEI Yanfang1,2, ZOU Jiankai1,3, WANG Peng4, ZENG Zhihui1

1.School of Electrical Engineering and Automation，Henan Polytechnic University，Jiaozuo  454000，Henan，China;2.Henan Key Laboratory of Intelligent Detection and Control of Coal Mine Equipment，Jiaozuo  454000，Henan，China;3.State Grid Anyang Power Supply Company，Anyang  455000，Henan，China;4.Electric Power Research Institute，State Grid Henan Electric Power Company，Zhengzhou  450052，Henan，China

Abstract: Objectives  To solve the problem of low solving efficiency of power flow algorithm for flexible DC transmission systems， Methods  firstly，a power flow algorithm based on the seventh-order NR method was proposed.Compared with the traditional power flow algorithm，this algorithm had a higher convergence order，which could effectively reduce the number of iterations and improve the efficiency of the algorithm.Then， an improved algorithm based on the seventh-order NR method with Broyden was proposed for the problem that the seventh-order NR method was computationally intensive in a single step iteration.It took advantage of the outstanding convergence characteristics of the seventh-order NR method to reduce the number of iterations， while retaining the advantage of the lower computational cost of the single-step iteration of the Broyden method to avoid the waste of computational power，resulting in a large improvement in computational efficiency.Further，a rule of thumb was proposed to determine the number of iterations of the high order NR method in the modified algorithm. Results  The modified IEEE standard examples were simulated and tested by the classical and improved methods，and the results showed that，compared with the classical NR method，the maximum error of AC and DC power flow results was 1×10-8 and 2×10-8.In terms of average computing time，the calculation time of the improved algorithm was reduced by about 61% compared with that of the classical NR method under four example systems as IEEE-14，IEEE-30，IEEE-57，IEEE-118.When the example system changed from double-ended to triple-ended and double-fed，the number of iterations of the improved algorithm remained unchanged，and the calculation time increased by 0.352 ms and 0.636 ms，respectively.In the case of heavy load，the improved algorithm had the highest computational efficiency and the preset number of iterations were simple.When the load value reached 2.992，the calculation time was only 60% of that of the classical NR method. Conclusions  The improved algorithm in this paper had the same accuracy as the classical NR method，but had more advantages in computing speed，and was more conducive to the application in extreme cases such as heavy loads.

Key words:voltage source converter;high voltage direct current;seventh-order NR method;Broyden method;power flow calculation