城市电网分区柔性互联装置的定容方法

分区柔性互联是解决大型城市交流电网发展问题的一个新思路,容量是影响互联装置造价的关键因素。提出了分区互联装置的定容方法。首先,介绍了城市电网分区互联装置的基本概念。其次,分析了基于模块化多电平换流器(MMC)的分区互联装置的功率运行范围,建立了装置容量和最大无功输出的分段线性关系,并分析得出改善无功输出能力的方法,为定容方法提供依据。然后,依据有功需求和无功需求,提出装置定容方法,其中,有功需求是为了解决分区故障后的元件过载问题所需支援的有功功率,无功需求是为了解决分区发生暂态故障后的电压失稳问题所需支援的动态无功功率。定容方法还考虑了装置的功率支援是否会破坏送端分区安全性或导致联络线过载。最后,所述方法应用于国内外首个220kV分区柔性互联示范工程的实际方案论证。

Capacity Dimensioning Method of Partitioned Flexible Interconnection Device in Urban Power Network

Flexible interconnection between partitions is a new way to solve the development problems of large urban AC power grid, and the capacity of the interconnection device is the key factor for its cost. The capacity dimensioning method of partitioned flexible interconnection device is presented. Firstly, the basic concept of the device between two partitions of the urban power grid is described. Secondly, through an analysis on power operation range of the device based on the modular multi-level converter(MMC), the piecewise linear relation between the capacity and the maximum output of reactive power is established, and the methods of improving the output of reactive power are obtained. Thirdly, the capacity dimensioning method of the device is put forward according to the active power demand and the reactive power demand. The active power demand is for solving the overload problems after faults, while the reactive power demand is to solve dynamic voltage instability problems when the transient faults occur. The capacity dimensioning method also considers whether the power support will destroy the security of the sending-end partition or lead to overload of the link lines. Finally, the capacity dimensioning method is applied to the world''s first 220 kV partitioned flexible interconnection demonstration project.