【作者】 南亚楠；

【导师】 张国山； 孙建刚；

【作者基本信息】 天津大学 ， 控制工程， 2011， 硕士

【摘要】 随着电力电子设备的广泛应用,配电网的电能质量问题日趋严重。配电网侧的静止同步补偿器(Distribution Static Synchronous Compensator,D-STATCOM)可以有效的解决配电网侧的许多电能质量问题,因此得到了广泛的关注。级联多电平10kV/±10MVar D-STATCOM其容量等级和电压均非常适用我国的中低压配电网,具有很大研究价值。论文首先建立了级联D-STATCOM数学建模,提出了相应的控制策略。整个控制器设计包括两个部分,其一是围绕D-STATCOM发出所需无功电流的电流闭环控制器部分,其二是为保持级联D-STATCOM直流侧电容电压所设置的电压闭环控制器部分。其中,电流环采用常用的基于dq解耦PI控制,而电压环采用多层次的直流电压控制方案,分别在总体、单相、单个三个层面上对有功分布进行控制,实现了电容电压的稳压控制。其次,针对D-STATCOM应用的配电网中谐波补偿的需要,在电流环PI控制器中引入了重复控制。把重复控制器与PI控制器串联起来使用,引入一个双环控制,重复控制器被用作外环,其输出信号用于产生内环的电流参考,并加入电流指令前馈。这样,就将重复控制器对谐波信号的高跟踪精度以及PI控制器响应的快速性综合在一个控制器中,得到了综合性能更好的控制系统。最后,本文介绍了载波移相SPWM调制(Carrier Phase Shifted-SPWM)的几种实现方式。调制方法是D-STATCOM控制中非常重要的一环,它控制开关管的通断,对装置的输出性能有重要的影响。载波移相SPWM是一种非常适合级联D-STATCOM的调制方法,它有几种不同的实现方式。实际应用中,选择不同的调制方法,装置的输出波形、损耗与效率是不同的。分析这几种载波移相SPWM实现方式的优缺点,从中选出最适合的一种方法是十分必要的。更多还原

【Abstract】 With the wide application of power electronic equipments, power quality problems of the distribution network become increasingly serious. Distribution Static Synchronous Compensator ( D-STATCOM) which can effectively solve the majority of power quality problems in the distribution network, has been more and more widely concerned. 10kV/±10M Var D-STATCOM based on cascaded multilevel converter has wide range of applications in media-voltage distribution network in China because of its capacity level and voltage. Consequently, it has great research value.Firstly, the mathematical model of the cascaded D-STATCOM is established, and the control strategy is presented. The whole controller includes two parts. One is the current closed loop controller which is used to provide reactive current to the D-STATCOM, and the other is the voltage closed loop controller which is designed to preserve the capacitor voltage in the DC side of the cascaded D-STATCOM. The current control strategy employs the common PI control method which is based on dq decoupling. And the capacitor voltage control uses the multilayer DC voltage control method which is able to control the active power distribution on general, phase and individual levels respectively. As a result, it can achieve the balance control of the capacitor voltage.Secondly, aiming at the demand for the harmonic compensation in the distribution network where the D-STATCOM is applied, the repetitive control into the traditional PI controller is introduced in the current loop. The repetitive controller and the PI controller are used in series. A double loop control is employed. The repetitive controller is used as the outside loop and its output signal is used to generate the current reference of the inner loop with the feed-forward current signal. As a result, the high tracking accuracy of the harmonic signal of the repetitive controller and the rapid response character of the PI controller are integrated in the advanced controller, contributing to the better performance of the whole control system.At last, several implement ways of the Carrier Phase Shifted SPWM are introduced in this paper. The modulation method is very important for D-STATCOM. It controls the switching device on and off and has heavily implication to the output performance of the D-STATCOM equipment. The CPS-SPWM is a very suitable way for the cascaded D-STATCOM, and it has several different implement ways. In the factual application, by choosing different modulation methods, the D-STATCOM will have different output waveforms, loss and efficiency. It is necessary for us to analysis the advantages and disadvantages of these methods and to choose the most suitable way.更多还原