新型单相多模块电压源型逆变器研究

发布时间：2019-01-01 17:14

【摘要】：为了应对化石燃料逐渐短缺和生存环境日益恶化的严峻局面,风能、太阳能、生物质能、地热能、潮汐能等可再生新能源发电技术得到了前所未有的飞速发展。与此同时,作为电能处理关键部分的PWM变换器也在新能源发电系统中得到了各种各样的应用。传统的电压源型逆变器在逆变过程中对直流侧蓄电池电压的苛刻要求使得其在实际应用中受到了极大的约束,难以满足直流侧蓄电池电压低于电网电压峰值时的并网要求;而传统的电流源型逆变器由于其电抗器损耗大、体积大、成本高等缺点也在推广、应用中受到了一定的限制。因此功能更加多样、控制更加灵活的逆变器成为了新能源发电系统领域极具创新性和挑战性的研究方向之一。首先,本文提出一种适用于低输入电压场合的新型单相多模块电压源型逆变器拓扑结构,详细分析了该新型多模块VSI系统工作原理及电压输出特性。采用交、直流混合的单极性PWM调制方式,得出交流侧输出电压与交流调制信号之间的函数关系,为后续的VSI系统分析打下基础。其次,详细分析了不同模态中,单极性PWM载波调制下电路的工作模式及桥臂电流的变化规律。依据VSI系统中交直流侧的能量守恒关系,完成了对H桥单元稳压电容器的参数设计;通过对不同模态中的典型等效电路分析,完成了对VSI系统回路电感参数的设计。最后,搭建了2kW的PSIM软件仿真系统和硬件实验平台,并完成了对新型VSI系统带有稳态负荷、阶跃负荷及感性负荷时的工作特性验证。仿真结果和实验结果表明,桥臂电流变化规律与理论分析一致,H桥单元稳压电容器参数和VSI系统回路电感参数设计合理,提出的新型VSI具有较大的升压能力并在阶跃负荷、感性负荷下依然具有良好的运行特性。
[Abstract]:In order to cope with the severe situation of the shortage of fossil fuels and the worsening of the living environment, new renewable energy generation technologies such as wind energy, solar energy, biomass energy, geothermal energy, tidal energy and so on, have been developed at an unprecedented speed. At the same time, as a key part of power processing, PWM converter has been widely used in new energy generation systems. The harsh requirements of DC side battery voltage of the traditional voltage source inverter in the process of inverter make it difficult to meet the grid connection requirements when the DC side battery voltage is lower than the peak voltage of the grid because of its great constraints in practical application. The traditional current-source inverter is also popularized because of its large reactor loss, large volume and high cost, so it is limited in application. Therefore, the inverter with more diverse functions and more flexible control has become one of the most innovative and challenging research directions in the field of new energy generation system. Firstly, a novel single-phase and multi-module voltage source inverter topology for low input voltage is proposed. The working principle and voltage output characteristics of the new multi-module VSI system are analyzed in detail. The function relationship between AC side output voltage and AC modulation signal is obtained by using AC / DC hybrid unipolar PWM modulation mode, which lays the foundation for subsequent VSI system analysis. Secondly, the operating mode of the circuit and the current variation of the bridge arm are analyzed in detail under unipolar PWM carrier modulation in different modes. According to the energy conservation relation of AC / DC side in VSI system, the parameter design of H-bridge unit voltage stabilized capacitor is completed, and the circuit inductance parameter of VSI system is designed by analyzing the typical equivalent circuit in different modes. Finally, the PSIM software simulation system and hardware experimental platform of 2kW are built, and the working characteristics of the new VSI system with steady load, step load and inductive load are verified. The simulation results and experimental results show that the current variation law of the bridge arm is consistent with the theoretical analysis, the parameters of H-bridge unit voltage stabilized capacitor and the inductance parameter of VSI system circuit are designed reasonably, and the new type of VSI has large boost capacity and step load. Under the inductive load, it still has good operation characteristics.
【学位授予单位】：东北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM464

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