一种新型基于级联多电平变换器的储能系统研究

发布时间：2019-01-10 16:05

【摘要】：大力发展风能太阳能等可再生能源,减少温室气体排放,建设环境友好型国家对我国的国家能源安全、环境改善、经济的可持续发展等具有非常重要的战略意义。与此同时,储能系统由于其能够灵活快速地调整有功／无功功率的吞吐、平抑负荷波动、提高电能质量等一系列优点,也得到了广泛关注和研究。相对的,储能系统直流侧电压/SOC均衡控制这一关乎储能系统运行质量的重要问题便显得日益重要。特别是链式储能系统,由于其具有结构简单且容易重构、等效输出电压高、等效开关频率高和输出电能质量好等一系列显著优点,而逐渐成为大容量储能系统中的研究热点。然而,链式储能系统高质量运行的关键在于系统充放电时直流侧各储能单元之间的能量均衡(如各蓄电池组间的荷电状态(SOC)的均衡)。本文首先在综合分析了各种多电平变换器调制策略的基础上,针对链式储能系统的均衡控制提出了一种基于辅助功率环的单相级联多电平储能系统,并提出了一种适合于该拓扑的双频载波移相PWM调制方法。通过该辅助功率环和双频载波移相PWM调制方法,提出了可以有效实现级联多电平储能系统直流侧各储能单元之间功率交换的调控机制。此外,文中还详细论述了系统输出滤波器和辅助功率环中调谐滤波器的设计方法。论文对基于辅助功率环的级联多电平储能系统的拓扑及其蓄电池SOC均衡控制方法进行了MATLAB/SIMULINK仿真分析,同时以蓄电池为储能元件,建立了一个由三个H桥模块级联而成的1kW单相蓄电池储能系统实验平台。仿真和实验结果验证了双频载波移相PWM调制方法及功率交换机制的可行性以及理论分析的正确性。
[Abstract]:It is of great strategic significance to develop renewable energy such as wind and solar energy, reduce greenhouse gas emissions and build environment-friendly countries for our country's energy security, environmental improvement and sustainable economic development. At the same time, energy storage system has been paid more and more attention because it can adjust active / reactive power huff and puff flexibly and quickly, suppress load fluctuation, improve power quality and so on. In contrast, DC side voltage / SOC equalization control of energy storage system is becoming more and more important. Especially for chain energy storage system, it has a series of remarkable advantages, such as simple structure, easy reconfiguration, high equivalent output voltage, high equivalent switching frequency and good output power quality, and has gradually become a research hotspot in large capacity energy storage system. However, the key to high quality operation of chain energy storage system lies in the energy balance between DC side energy storage units (such as the charge state (SOC) balance between battery groups) during charging and discharging of the system. Based on the comprehensive analysis of various modulation strategies of multilevel converters, a single-phase cascaded multilevel energy storage system based on auxiliary power loop is proposed in this paper for the equalization control of chain energy storage systems. A dual frequency carrier phase-shifted PWM modulation method is proposed for this topology. By means of the auxiliary power loop and the dual-frequency carrier phase-shifted PWM modulation method, an effective power exchange control mechanism between the DC side energy storage units of cascaded multilevel energy storage system is proposed. In addition, the design method of the system output filter and the tuning filter in the auxiliary power loop are discussed in detail. In this paper, the topology of cascade multilevel energy storage system based on auxiliary power loop and the SOC equalization control method of battery are simulated and analyzed by MATLAB/SIMULINK. At the same time, the battery is used as energy storage element. An experimental platform for energy storage system of 1kW single-phase battery is established, which consists of three H-bridge modules. Simulation and experimental results verify the feasibility of dual-frequency carrier phase-shifted PWM modulation method and power exchange mechanism, as well as the correctness of theoretical analysis.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM46

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