低压多端直流配电系统的电压控制主站选取分析研究

Analysis and Research on Selection of Voltage Control Master Station in Low Voltage Multi-terminal DC Distribution System

多端直流配电是未来电网的重要形态之一,其电压控制主站的选取直接影响着系统稳定性能。该文针对多端直流配电系统,选取手拉手典型结构作为研究对象,提出一种便捷的电压控制主站选取分析方法,涵盖主站直流电压控制环路构建、从站模块等效阻抗建模,以及适用于主站选取分析的全局传递函数,并以稳定运行边界优劣作为选取分析的依据。在此基础上,当选取不同换流站作为主站时,利用所提方法进行系统稳定运行边界的比对研究,并分析主站位置偏移下的稳定运行边界变化趋势。结合实际算例,通过Matlab/Simulink对理论分析进行了测试验证。研究结果表明,所提方法能够便捷实现低压多端直流配电系统的主站选取、有效提升系统稳定性。

Multi-terminal DC distribution is one of the important forms of a power grid in the future.The selection of its voltage control master station directly affects the stability of the system.Aiming at the multi-terminal DC distribution system,this paper selects the typical hand-in-hand structure as the research object,and puts forward a convenient analysis for the selection of the voltage control master station.This method includes the construction of DC voltage control loop of the master station,the equivalent impedance modeling of the slave station module,and the global transfer function suitable for the selection and analysis of the master station.It takes the advantages and disadvantages of the stable operation boundary as the basis for selection and analysis.On this basis,when different converter stations are selected as the main station,the proposed method is used to study the stable operation boundary of the system.The change trend of the stable operation boundary under the position offset of the main station is analyzed.Combined with practical examples,the theoretical analysis is tested and verified by the Matlab/Simulink.The results show that the proposed method can conveniently realize the selection of the master station of a low-voltage multi-terminal DC distribution system and effectively improve the system stability.