基于空间矢量调制技术的链式STATCOM的研究

发布时间：2018-06-06 07:46

本文选题：STATCOM + 级联链式多电平结构　；参考：《东南大学》2015年硕士论文

【摘要】：随着现代电力电子技术的快速发展,电力电子装置容量的累积增长,使得电力电子装置在公用电网中产生的电能质量问题日益严重,对电力系统安全、稳定、经济运行构成潜在的威胁,使得电能质量受到了严重的影响。因此如何改善电能质量问题,越来越受到用户和电力部门的关注。无功功率作为衡量电能质量的重要指标,如果其不能保证系统稳定运行,其将会降低系统的静态稳定裕度,导致系统稳定性降低,增加线路损耗,在变压器和线路上产生额外的电压损耗等。因此,研究如何对无功功率进行有效补偿具非常重要的意义。静止同步补偿器(STATCOM)作为一种较理想的无功补偿设备,得到了越来越深入的研究和广泛的应用。在高电压、大功率场合,链式STATCOM常采用传统SPWM调制,其直流电压利用率不高,需要多个H桥级联,成本较高、可靠性较低。空间矢量调制技术(SVPWM)有提高电压利用率的优点,可以有效的减少H桥的个数,但当电平数较多时,其计算过于复杂。因此本文介绍了一种应用于星形连接链式STATCOM的简化SVPWM算法,将两电平空间矢量调制技术与载波移相调制技术相结合,能够有效提高直流电压利用率并且降低计算的复杂性；在此基础上,本文提出一种直流电压分层控制策略,以实现各H桥直流侧电压的稳定与均衡。在仿真软件PSCAD中搭建模型进行仿真,验证了该调制算法及直流电压控制策略的正确性及可行性。最后设计搭建一套硬件装置来对仿真进行实验验证。本文的主要研究内容有：首先研究了多电平STATCOM的不同拓扑结构以及STATCOM常用的几种调制策略；其次介绍了空间矢量调制技术,并研究了载波移相技术同空间矢量调制技术的结合,实现多电平空间矢量调制技术的简化；然后对STATCOM的交流侧和直流侧的控制策略进行了研究；最后对基于SVPWM的级联STATCOM的硬件和软件进行了介绍,并通过仿真和实验波形,验证了本文所提出的控制策略和硬件软件设计的有效性。最后对本文所做的工作进行了系统的总结,指出了其中的不足,并对今后的研究工作内容作了展望。
[Abstract]:With the rapid development of modern power electronics technology and the accumulative growth of power electronic device capacity, the power quality problem caused by power electronic device in public power network is becoming more and more serious, which is safe and stable for power system. Economic operation poses a potential threat, which seriously affects the power quality. Therefore, how to improve the power quality has attracted more and more attention from users and power departments. Reactive power as an important index to measure power quality, if it can not guarantee the stable operation of the system, it will reduce the static stability margin of the system, resulting in lower stability of the system and increase the line loss. Generate additional voltage losses on transformers and lines, etc. Therefore, it is very important to study how to compensate reactive power effectively. As an ideal reactive power compensator, static synchronous compensator (STC) has been studied more and more deeply and applied widely. In high voltage and high power situations, traditional SPWM modulation is often used in chain type STATCOM. Its DC voltage utilization ratio is not high, and many H-bridge cascades are needed, which have high cost and low reliability. Space Vector Modulation (SVPWM) has the advantages of improving the voltage utilization ratio and can effectively reduce the number of H-bridges, but when the number of level is more, its calculation is too complex. Therefore, this paper introduces a simplified SVPWM algorithm applied to star connected chain STATCOM. The combination of two-level space vector modulation and carrier phase-shifted modulation can effectively improve the utilization rate of DC voltage and reduce the complexity of calculation. On this basis, a hierarchical control strategy of DC voltage is proposed to realize the stability and equalization of the voltage at the DC side of each H bridge. A simulation model is built in the simulation software PSCAD to verify the correctness and feasibility of the modulation algorithm and DC voltage control strategy. Finally, a set of hardware device is designed to verify the simulation. The main contents of this paper are as follows: firstly, the different topology of multilevel STATCOM and several modulation strategies commonly used in STATCOM are studied; secondly, the space vector modulation technology is introduced, and the combination of carrier phase shift technology and space vector modulation technology is studied. The control strategy of AC side and DC side of STATCOM is studied. Finally, the hardware and software of cascaded STATCOM based on SVPWM are introduced, and the simulation and experimental waveform are given. The effectiveness of the proposed control strategy and hardware and software design is verified. Finally, the work done in this paper is systematically summarized, the shortcomings are pointed out, and the future research work is prospected.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM761.12

【相似文献】