换流站导体载流量计算方法比较与研究

Comparison and Research on Ampacity Calculation Methods of Conductor in Converter Station

摘要:

导体载流量计算是直流换流站设计的重要组成部分，目前国内尚无规程规范规定直流换流站导体载流量的计算方法。鉴于直流换流站导体承受的电流应力较为复杂，本文首先根据载流量计算的基本原理，给出了换流站中不同载流工况下导体载流量计算的基本原则，确定了适用于换流站导体载流量计算的修正的热平衡方程。在载流量计算方法方面，综合分析比较了电气一次设计手册、DL/T 5221-2005、IEEE 738-2012、IEEE 605-2008、IEC 61597-1995等五处规程规范给出的交流导体载流量计算方法及其计算结果，重点对比其中不同的对流散热功率计算方法。建议采用修正的《电气一次手册》计算方法计算换流站户外导体载流量；可根据导体外径不同分别采用IEEE 738推荐方法和DL/T 5222实际采用的方法计算换流站户内导体载流量。

Abstract:

The calculation of conductor ampacity is an important part of the design of DC converter station. At present, there is no code for calculating the conductor ampacity of DC converter station. In view of the complexity of current stress on the conductor of DC converter station, the basic principle of conductor ampacity calculation under different current-carrying conditions in converter stations is given according to the basic principles of current-carrying capacitycalculation, and the modified heat balance equation suitable for the conductor ampacity calculation in converter station is determined. In terms of current-carrying capacity calculation method, the calculation methods and their results of current-carrying capacity of AC conductor given by five codes and specifications, including electrical primary design manual, DL /T 5222-2005, IEEE 738-2012, IEEE 605-2008 and IEC 61597-1995, are comprehensively analyzed and compared, and different calculation methods of convective heat dissipation power are emphatically compared. It is suggested to use the modified calculation method of primary electrical manual to calculate the outdoor conductor ampacity in converter stations, and according to the different outer diameter of conductors, the recommended method by IEEE 738 and the actual method by DL/T 5222 can be used to calculate indoor conductor ampacity of converter station.