中文摘要：

为降低逆变器产生的谐波电流,在三相电压源型逆变器（VSI）与电网间通常需要接入网侧接口滤波器。然而,由于配电网本身是一种弱电网,是非理想电网,因此,通常只能将其等效为电压源串联阻抗,这样,当有多台带滤波器的VSI接入配电网时,VSI之间就可能产生交互作用。文章研究了当多台带滤波器的逆变器通过阻抗耦合时的不稳定现象,证明了即使配电网中各VSI的接口滤波器参数的设置满足单独接入要求,仍然会产生谐振现象;此外,研究了参数选取的稳定域,采用小信号环分析法,对稳定性问题进行了评估,并且对采用阻抗法时不稳定边界进行了定位。最后,通过逐周期仿真和实验验证了该谐振现象以及重要设计参数的稳定性边界值。

英文摘要：

The use of interface-filter for reducing current harmonics has been commonly used for three-phase voltage source inverters （VSL） connected to the power grid. However, the power grid in a typical distribution system is non- ideal, presenting itself as a voltage source with series connection impedance. Thus, an inverter using an interface-fil- ter may interact with other inverters connecting to the grid via the non-ideal grid. In this paper, the irreversible insta- bility phenomenon of the three-phase voltage source inverters with filter through impedance coupling is studied. We show that resonant oscillation occurs in the distributed power grid, even if the voltage source inverter with interface-fil- ter is well designed for standalone applications. Specifically, the stable operating region in selected parameter space is studied. A small-signal loop analysis is performed to predict this stability problem and to locate the boundary of the instability using an impedance approach. Finally, the phenomenon and design-or/ented stability boundaries are verified by cycle-by-cycle simulations and experimental measurements.