The high penetration of renewable energy sources always leads to the fluctuation of the droop coefficients which are designed in inverse proportion to their rated capacity, and power electronics devices are prone to static instability. Although the impedance-based approaches have been widely studied to deal with this problem, the stability-oriented droop coefficients region identification due to the fluctuation of renewable energy sources is not provided. Thus, this article proposes an impedance-based approach to assess the droop coefficients stability region in the power system consisting of numerous distributed generators (DGs). First, the modified phase margin and opposing argument (MPMOA) forbidden criterion is constituted to acquire the complementary space of the droop coefficients stability region. The MPMOA forbidden criterion is first transformed into the condition that the generalized return-ratio matrix is Hurwitz through mirror, rotation, and translation mapping. In comparison with the previous simplified stability criteria, the conservatism of the proposed criterion is reduced a lot. Thereafter, the droop coefficients stability region is directly calculated by the generalized return-ratio matrix and guardian map theory. Eventually, the simulation and experimental results are provided to validate the conservatism and effectiveness of the impedance-based stability region identification approach. Therein, the simulation results illustrate that the proposed droop coefficients stability operation criterion has lower conservatism than these of the previous simplified stability criteria. Furthermore, the simulation and experimental results illustrate that the proposed stability-oriented droop coefficients region identification approach can provide an effective parameter stability region.

中文翻译：

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弱电网中逆变器的面向稳定性的下垂系数区域识别：基于阻抗的方法

可再生能源的高渗透率总是导致下垂系数的波动，该下垂系数的设计与它们的额定容量成反比，并且电力电子设备容易出现静态不稳定性。尽管已经广泛研究了基于阻抗的方法来解决该问题，但是由于可再生能源的波动而没有提供面向稳定性的下垂系数区域识别。因此，本文提出了一种基于阻抗的方法来评估由众多分布式发电机（DG）组成的电力系统中的下垂系数稳定区域。首先，构造修改后的相位裕度和相对论点（MPMOA）禁止准则，以获取下垂系数稳定区域的互补空间。首先通过镜像，旋转和平移映射将MPMOA禁止准则转换为广义收益率矩阵为Hurwitz的条件。与以前的简化稳定性准则相比，该准则的保守性大大降低了。此后，利用广义收益率矩阵和监护图理论直接计算下垂系数的稳定区域。最终，提供了仿真和实验结果，以验证基于阻抗的稳定区域识别方法的保守性和有效性。其中，仿真结果表明，所提出的下垂系数稳定性操作准则与先前的简化稳定性准则相比具有较低的保守性。此外，