The application of virtual synchronous generators in the power system eases the pressure on the grid caused by penetration of lots of power electronic devices, but worsens the dynamic frequency stability of the grid. Meanwhile, in order to solve the problem of power coupling in low-voltage micro-grid systems, most measures introduced virtual impedance technology to adjust the equivalent output impedance of the system. Therefore, most studies have adopted the adaptive control strategy of the moment of inertia, to improve the dynamic frequency adjustment of the grid. However, it will cause the frequency response speed reduction problem. In order to deal with the contradiction between the moment of inertia and frequency response speed, the voltage phasor relationship of the micro-source - grid system under signal disturbance in the introduction of virtual impedance is analyzed. Then an adaptive virtual impedance control strategy is proposed to accelerate the active power adjustment process of the virtual synchronous generator system, which helps to complete the first frequency modulation and improve the inertia adjustment ability. Finally, combining these two control strategies, a coordinated adaptive moment of inertia and virtual impedance control strategy is proposed. From the perspective of the moment of inertia and virtual impedance, the proposed method fully exploits the control advantages of the virtual synchronous generator system and achieves the purpose of adjusting the inertia of the virtual synchronous generator system while considering the acceleration of the frequency response speed. The comprehensive simulation results verify the feasibility and effectiveness of the proposed method.

中文翻译：

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基于惯性矩和虚拟阻抗的虚拟同步发电机协调控制策略

虚拟同步发电机在电力系统中的应用减轻了许多电力电子设备的渗透对电网造成的压力，但恶化了电网的动态频率稳定性。同时，为了解决低压微电网系统中的功率耦合问题，大多数措施引入了虚拟阻抗技术来调整系统的等效输出阻抗。因此，大多数研究都采用了惯性矩的自适应控制策略，以改善电网的动态频率调节。但是，这会引起频率响应速度降低的问题。为了解决惯性矩与频率响应速度之间的矛盾，分析了虚拟阻抗引入下信号干扰下微源－电网系统的电压相量关系。然后提出一种自适应虚拟阻抗控制策略，以加速虚拟同步发电机系统的有功功率调整过程，有助于完成第一调频，提高惯性调整能力。最后，结合这两种控制策略，提出了一种协调的自适应惯性矩和虚拟阻抗控制策略。从转动惯量和虚拟阻抗的角度来看，该方法充分利用了虚拟同步发电机系统的控制优势，达到了在考虑频率响应速度加速的同时调整虚拟同步发电机系统惯量的目的。综合仿真结果验证了该方法的可行性和有效性。