基于反馈线性化控制的柔性互联装置冲击电流抑制方法

Impulse Current Suppression Method for Flexible Interconnection Device based on Feedback Linearized Control

柔性互联系统能够改变潮流的自然分布、实现功率融通,连续且快速调控相连馈线的有功和无功功率,支持电网的高可靠运行,在铁路交通、金融、通信等领域得到了广泛的应用。当一侧交流系统因故障停电时,失电侧负荷改由另一侧系统通过柔性互联装置供电,实现重要负荷的连续供电,此时投入感性负载或非线性负载时,会给柔性互联装置带来较大的冲击电流。本文首先分析了投入感性负载时冲击电流产生机理,推导出了冲击电流的表达式;其次,为抑制冲击电流,分析了柔性互联装置单侧换流器的物理系统,并根据物理系统数学模型设计了基于反馈线性化的控制系统;最后,在PSCAD/EMTDC中搭建了双端柔性互联系统的仿真模型,通过与传统控制方法对比,验证本文所述控制方法对冲击电流的抑制效果。

Flexible interconnection system can change the natural distribution of power flow,realize power integration,continuously and quickly regulate the active and reactive power of connected feeders,and support the high reliable operation of power network.It has been widely used in railway transportation,finance,communication and other fields.When power of the AC system on one side is off due to occurrence of faults,the load on the side without power source will be fed by the system on the other side through flexible interconnection device to realize continuous power supply of important loads,when inductive load or nonlinear load is input at this time,it will bring large impulse current to the flexible interconnection device.Firstly,the generation mechanism of impulse current is analyzed when inductive load is input,and the expression of impulse current is deduced;secondly,in order to suppress the impulse current,the physical system of the single-sided converter of the flexible interconnection device is analyzed,and the control system based on feedback linearization is designed according to the mathematical model of the physical system;finally,the simulation model of two terminal flexible interconnection system is built in PSCAD/EMTDC.Compared with the traditional control method,the suppression effect of the control method illustrated in the paper on impulse current is verified.