适用于MMC-MTDC的自适应斜率平坦控制策略  

Adaptive Droop Flatness Control Strategy for MMC-MTDC

作　　者：宋平岗 董辉 周振邦 

机构地区：[1]华东交通大学电气与自动化工程学院,南昌330013

出　　处：《高电压技术》2017年第10期3265-3272,共8页High Voltage Engineering

基　　金：国家自然科学基金(51367008)~~

摘　　要：为了维持模块化多电平换流器多端直流输电系统的电压稳定及换流站间功率的平衡,提出一种基于微分平坦理论的自适应斜率控制策略。控制器分为前馈双环控制和动态误差反馈控制:前馈控制根据系统期望平坦输出参考轨迹和系统状态变量及输入变量之间的函数关系,得到控制系统的主导控制量;误差线性反馈控制可以消除系统扰动和外界干扰对规划轨迹的影响,增强系统响应速度和稳态暂态特性。最后建立五端MMC-MTDC模型,分别在稳态潮流翻转和主站故障退出2种工况下进行仿真验证。结果表明该控制策略可以根据电压变化方向及换流站裕度对下垂曲线斜率实时控制,避免换流站满载甚至过载运行,达到各个换流站之间功率的最优分配。In order to maintain the voltage stability and the balance of power between converter stations for MMC-MTDC,a differential flatness based on adaptive droop control strategy is proposed.The controller consists of a feed-forward double loop control and dynamic error feed-back control.The feed-forward control is based on the reference trajectory according to the system flat output expected and the functional relationship between system state variables and input variables.First,the dominant control of the control system is obtained.The linear feed-back error control eliminates the impacts of system disturbance and external disturbance on the trajectory of the system.Then,the system response speed and transient and steady-state characteristics are enhanced.Finally,an MMC-MTDC simulation model including five stations is established in PSCAD/EMTDC.Simulations are performed to validate the feasibility of power flow inversion in steady state and the outage broken main station.The results show that the control strategy can be adopted to control the droop coefficient according to the direction of DC voltage variation and converter margin.Converters can avoid the full or overload operation.All the converters can achieve their optimal power sharing.

关 键 词：模块化多电平换流器 多端直流输电系统 自适应斜率控制 微分平坦理论 功率最优分配 

分 类 号：TM46[电气工程—电器] TM721.1