节点文献
自抗扰控制技术在轻型高压直流输电系统中的应用
Application of Auto-Disturbance-Rejection Technique in VSC-HVDC
【作者】 范彬;
【导师】 王奔;
【作者基本信息】 西南交通大学 , 电力系统及其自动化, 2013, 硕士
【摘要】 VSC-HVDC输电技术因具有高度可控性的优点而在电力系统中得到越来越广泛的应用。与传统直流输电相比,它能够实现有功功率和无功功率的独立调节。本文利用自抗扰控制技术,对VSC-HVDC和VSC-MTDC换流器控制策略进行分析与研究。(1)介绍自抗扰控制技术的发展及其优点,在多阶及二阶自抗扰控制器的基础上,设计出实用性更强的一阶自抗扰控制器;(2)通过对电压源整流器工作原理及数学模型研究,建立了基于电压源换流器的连接双端有源网络的VSC-HVDC模型。为了减少控制器对系统数学模型的依赖性,利用自抗扰控制技术,设计出直接电流控制的外环定直流电压控制器、定有功功率控制器和定无功功率控制器,并对内环控制器采用最优控制函数,最终实现动态响应快、鲁棒性强、对外扰不敏感的控制目标。(3)建立三端VSC-MTDC模型,其中两端换流器连接有源网络,另一端连接无源网络。结合双端VSC-HVDC系统自抗扰控制器与主从式控制的方法,将该控制策略用于所建立的三端VSC-MTDC系统中,仿真结果表明控制策略的有效性。一阶自抗扰控制器具有设计过程简单、运算速度快、可靠性高的优点。通过对双端VSC-HVDC和三端VSC-MTDC系统进行数字仿真,验证了使用自抗扰控制器的直流输电系统在潮流反转、有功功率阶跃、无功功率阶跃、交流系统故障及直流电压下降时的有效性。
【Abstract】 VSC-HVDC transmission technology possesses the advantages of high controllability and gets more and more widely used in electric power system. Compared with the traditional dc transmission, it is able to achieve the independent regulation of active power and reactive power.In this paper, on the basis of the Auto Disturbance Rejection technique, the VSC-HVDC and the VSC-MTDC converter control strategies have been analysised and researched.(1) Introduced the development Auto Disturbance Rejection technique and its advantages,on the basis of the multi-order and second-order Auto Disturbance Rejection Controller,designed a more useful ADRC of one-order.(2) Based on voltage source rectifier working principle and mathematical model research, constructted the model of double terminal VSC-HVDC. For reduce the dependence of the controller on the system mathematical model,designed a direct current controller of outer loop controller with the constant dc voltage,the active power controller and the reactive power controller, of the inner loop controller using optimal control function.Finally realizes the fast dynamic response, strong robustness and external disturbance not sensitive control objectives.(3) Three terminal VSC-MTDC model is set up, including two terminals connected to active networks and one terminal to passive network.Together with voltage margin control methods,ADRC is used on the system.The first-order ADRC have the advantages of simplely design process,fastly speed and highly reliability.Based on the result of digital simulation for double terminal VSC-HVDC and three terminal VSC-MTDC,verifyed the effectiveness of ADRC in power flow reversal step,active power step,reactive power step,ac system fault and dc voltage drop.
【Key words】 Voltage source converter; VSC-HVDC; VSC-MTDC; Voltage margin control;