基于混合级联多电平换流器的STATCOM研究

发布时间：2018-06-20 01:56

本文选题：静止同步补偿器 + 混合级联多电平换流器　；参考：《浙江大学》2014年硕士论文

【摘要】：静止同步补偿器(Static Synchronous Compensator,STATCOM)作为一种并联型无功补偿FACTS装置,因其良好的动态特性受到广泛重视。随着我国输电容量和负荷的不断增大,无功补偿向着高压大容量发展,链式STATCOM因具有模块化、多电平特性,便于扩展和实现冗余,成为无功补偿方面的研究和应用热点。近年来,链式主电路拓扑又有了新的发展,出现了混合级联多电平拓扑,为高压大容量无功补偿装置的研制开辟了一条新思路。本文提出了一种基于混合级联多电平换流器(Hybrid Cascaded Multilevel Converter, HCMC)的新型STATCOM,简称HCMC-STATCOM,主要研究了HCMC-STATCOM的控制策略、调制策略、H桥电容电压平衡控制策略和直流电容参数设计问题。本文提出的HCMC-STATCOM由常规二电平电压源换流器和H桥子模块级联而成的整形电路两部分构成。在其拓扑结构的基础上分析了HCMC-STATCOM的基本工作原理,并且建立了交流系统平衡情况下HCMC-STATCOM在三相静止坐标系和两相同步旋转坐标系下的数学模型。研究了功率前馈解耦控制策略,并设计了控制器实现整形电路和二电平换流器的协调配合,以及直流电容电压的控制；详细阐述了整形电路两种调制策略单极倍频载波移相SPWM调制策略(Carrier Phase-Shifting SPWM,CPS-SPWM)和最近电平逼近调制(Nearest Level Modulation,NLM)的实现方法；详细分析了HCMC-STATCOM的启动控制策略；利用PSCAD/EMTDC仿真验证了所提出控制策略、调制策略和启动策略的有效性。整形电路H桥直流电容电压的平衡是HCMC-STATCOM正常运行的前提。本文研究了在CPS-SPWM和NLM两种不同调制策略下的H桥直流电容电压平衡控制策略；通过PSCAD/EMTDC仿真对提出的电容电压平衡控制策略进行了有效性验证。直流电容器的参数直接影响HCMC-STATCOM的整体性能,本文对整形电路H桥直流电容和二电平换流器直流电容进行了理论参数设计；对HCMC-STATCOM与链式STATCOM在H桥数目、功率器件数目以及直流电容大小、数目以及所储存的能量方面进行了分析比较;总结了HCMC-STATCOM相对链式STATCOM和其他STATCOM的优点和缺点;利用PSCAD/EMTDC仿真对上述参数设计和分析进行了验证。
[Abstract]:Static synchronous compensator (static synchronous compensator), as a shunt reactive power compensator facts device, has been paid more and more attention for its good dynamic characteristics. With the increasing of transmission capacity and load in our country, reactive power compensation is developing to high voltage and large capacity. Because of its modularization, multilevel characteristic, easy to expand and realize redundancy, it has become the research and application hotspot of reactive power compensation. In recent years, new developments have been made in the topology of chained main circuit, and a hybrid cascade multilevel topology has emerged, which opens a new way of thinking for the development of high-voltage and large-capacity reactive power compensator. In this paper, a novel STATCOM-based hybrid cascade multilevel converter (HCMC-based) is proposed. The control strategy, modulation strategy and voltage balance control strategy of HCMC-STATCOM and the design of DC capacitance parameters are studied. The HCMC-STATCOM proposed in this paper consists of a conventional two-level voltage source converter and an H-bridge sub-module cascaded into two parts of the shaping circuit. Based on the topology of HCMC-STATCOM, the basic working principle of HCMC-STATCOM is analyzed, and the mathematical model of HCMC-STATCOM in three-phase stationary coordinate system and two-phase synchronous rotating coordinate system is established. The power feedforward decoupling control strategy is studied, and the controller is designed to realize the coordination of the shaping circuit and the two-level converter, as well as the control of the DC capacitor voltage. The realization methods of Carrier Phase-Shifting SPWMM (Carrier Phase-Shifting SPWMn) and nearest level Modulation (NLMM) are described in detail, and the startup control strategy of HCMC-STATCOM is analyzed in detail. The effectiveness of the proposed control strategy, modulation strategy and startup strategy is verified by PSCAD / EMTDC simulation. The balance of DC capacitor voltage of H bridge in shaping circuit is the premise of HCMC-STATCOM in normal operation. In this paper, the H bridge DC capacitor voltage balance control strategy based on CPS-SPWM and NLM modulation strategies is studied, and the effectiveness of the proposed capacitor voltage balance control strategy is verified by PSCAD / EMTDC simulation. The parameters of DC capacitors directly affect the overall performance of HCMC-STATCOM. In this paper, the theoretical parameters of H-bridge DC capacitor and two-level converter DC capacitor in shaping circuit are designed, and the number of HCMC-STATCOM and linked Statcom in H-bridge is discussed. The number of power devices, the size of DC capacitance, the number of DC capacitors and the energy stored are analyzed and compared, the advantages and disadvantages of HCMC-STATCOM relative to chain Statcom and other Statcom are summarized, and the design and analysis of these parameters are verified by PSCAD / EMTDC simulation.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM761.12;TM46

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