A virtual synchronous generator (VSG) control-based grid-connected converter (GCC) is an attractive solution to improve the stability of a more renewable-energy-integrated power system. Unfortunately, the inherent power coupling (i.e., the interaction between the active power loop and the reactive power loop) defect of VSG control severely restricts the power delivery capacity and the grid support capability of the GCC. The virtual inductor is commonly used to reduce coupling, but its decoupling capability is very limited. In addition, the power coupling mechanism and its limiting factors are not clear. For this issue, the nature of power coupling in the VSG system is investigated first. The decoupling capability of the virtual inductor is studied, and the reason for decoupling effectiveness is revealed. It indicates that the effectiveness of decoupling results from the proper voltage compensation, but this kind of positive effect is limited by the d-axis voltage drop across the virtual inductor. Then, a q-axis voltage-drop-based power decoupling control (QVPDC) is proposed to further reduce the power coupling, which does not consider the d-axis voltage drop when applying the virtual inductor. Compared with the virtual-inductor-based decoupling method, the decoupling performance of QVPDC is better, and the computation burden is reduced by half. Finally, the analysis and the proposed method are validated by simulation and experiment.

中文翻译：

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虚拟同步发电机功率耦合机理分析及改进解耦控制

基于虚拟同步发电机 (VSG) 控制的并网转换器 (GCC) 是一种有吸引力的解决方案，可提高更多可再生能源集成电力系统的稳定性。不幸的是，VSG 控制固有的功率耦合（即有功功率回路和无功功率回路之间的相互作用）缺陷严重限制了 GCC 的功率输送能力和电网支持能力。虚拟电感常用于降低耦合，但其去耦能力非常有限。此外，功率耦合机制及其限制因素尚不清楚。对于这个问题，首先研究 VSG 系统中功率耦合的性质。研究了虚拟电感器的去耦能力，揭示了去耦有效性的原因。这表明去耦的有效性来自适当的电压补偿，但这种积极影响受到虚拟电感器两端的 d 轴电压降的限制。然后，提出了一种基于q轴压降的功率去耦控制（QVPDC）以进一步降低功率耦合，该控制在应用虚拟电感时不考虑d轴压降。与基于虚拟电感的解耦方法相比，QVPDC的解耦性能更好，计算负担减少一半。最后，通过仿真和实验验证了分析和提出的方法。提出了基于 q 轴压降的功率去耦控制 (QVPDC) 以进一步降低功率耦合，该控制在应用虚拟电感时不考虑 d 轴压降。与基于虚拟电感的解耦方法相比，QVPDC的解耦性能更好，计算负担减少一半。最后，通过仿真和实验验证了分析和提出的方法。提出了基于 q 轴压降的功率去耦控制 (QVPDC) 以进一步降低功率耦合，该控制在应用虚拟电感时不考虑 d 轴压降。与基于虚拟电感的解耦方法相比，QVPDC的解耦性能更好，计算负担减少一半。最后，通过仿真和实验验证了分析和提出的方法。