【作者】 雷彪；

【导师】 马皓；

【作者基本信息】 浙江大学 ， 电力电子与电力传动， 2006， 硕士

【摘要】 逆变器的并联运行有利于提高电源系统的可靠性和容量,无信号连接线的逆变器并联系统与有信号连接线的逆变器并联系统相比又具有位置摆放更方便、并联时接线少、冗余度高等优点,是当今电力电子学科研究的一个热点。 本文详细介绍了逆变器电流内环电压外环双环控制器参数的设计方法,接着介绍了现有的逆变器无连线并联技术(主要是PQ下垂控制法)的原理,给出了不同条件下的均流控制方程,从理论上分析了逆变器与负载间连线阻抗存在差异时逆变器输出电流的均分情况,并进行了仿真验证。为了降低连线阻抗差异对功率均分的影响,本文介绍了两种改进的PQ下垂控制法:输出阻抗调整法和谐波注入法。并提出了一种改进的均流控制方法:PQ系数调整法,对这种新方法进行了仿真和实验验证。由于上面分析的均流控制法只能控制交流环流,为消除直流环流,本文设计了一个“直流环流消除器”,仿真和实验结果都证实了该直流环流消除器能有效抑制直流环流。 其次,本文建立了基于下垂控制法的逆变器无连线并联系统的小信号模型,利用该模型分析了下垂系数对并联系统稳定性的影响,并选取了合适的下垂系数。 最后,实验结果证实了理论分析,验证了基于小信号模型的下垂系数设计方法的可行性及改进的均流控制方法能有效提高均流度。更多还原

【Abstract】 In order to ensure redundancy, expandability and good reliability of a power supply system, a parallel-inverter power supply system is required. Generally, there are two kinds of parallel-inverter power supply system: parallel-inverter system with control interconnections and parallel-inverter system without control interconnections. As the latter is more flexible and easier to expand, it is studied more and more nowadays.In this thesis, an inverter controller composed of voltage-loop and current-loop was introduced, then the principle of power distribution (P-Q droop method) was analyzed and the function to control the output power was presented. Influence of cable impedance’s deviation on the power distribution was studied in theory and validated by simulation. In order to weaken this influence, two improved droop method, harmonic injection method and output impedance regulation method, was introduced. And a novel improved droop method, P-Q droop coefficient regulation method, was proposed. Simulation results validated this proposed method. As methods mentioned above could only distribute Alternating Current, a DC circum current attenuator was designed.In the following part of this paper, a generalized small-signal model for parallel-inverter power supply system was presented. With the small-signal model, the stability of the system could be studied and the droop coefficients be chosen properly.Finally, experiment results were showed, which proved what had studied in theory and in simulation.更多还原