Modeling and Analysis of Inner Controls Effects on Damping and Synchronizing Torque Components in VSG-Controlled Converter
Modeling and Analysis of Inner Controls Effects on Damping and Synchronizing Torque Components in VSG-Controlled Converter
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DOI：
10.1109/tec.2020.3010049
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发表时间：
2020-07
影响因子：
4.9
通讯作者：
Z. Qu;J. Peng;Huan Yang;D. Srinivasan
中科院分区：
文献类型：
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作者：
Z. Qu;J. Peng;Huan Yang;D. Srinivasan
在虚拟同步发电机（VSG）相关的讨论中，内部电压和电流控制往往被忽略，由于其快速动态。然而，随着额定功率的增加，转换器需要较低的开关频率，这限制了级联控制的带宽。因此，应分析不同时间尺度的对照之间的相互作用。具体而言，其目的是揭示内部控制回路的VSG系统的转矩的角度来看的效果。首先，本文推导了一个线性化模型的内部电压的相位和幅值，它准确地描述了VSG系统的特性。随后，基于此线性化模型，我们推导出一个等效的单输入单输出运动方程为基础的模型。该模型可用于研究低控制带宽和弱电网条件下阻尼和同步转矩分量的变化。最后，仿真结果验证了所提出的建模和效果分析。该模型具有通用性，适用于任何额定功率，为设计VSG系统的控制参数提供了指导。
In virtual synchronous generator (VSG)-related discussions, the inner voltage and current controls are always omitted due to their fast dynamics. However, converters require a lower switching frequency as their power rating increases, which constrains the cascaded controls’ bandwidths. Hence, the interactions between the controls at different time-scales should be analyzed. Specifically, the aim is to reveal the effects of inner control loops on the VSG system from the torque perspective. First, this paper derives a linearized model of the internal voltage phase and amplitude, which accurately depicts the VSG system characteristics. Subsequently, based on this linearized model, we derive an equivalent single-input single-output motion-equation- based model. The proposed model can be used to investigate the change in damping and synchronizing torque components under low control bandwidths and weak grid conditions. Finally, simulation results are presented to validate the proposed modeling and effects analysis. Our model is general and can be used for any power ratings, and the study also provides a guide to designing control parameters for VSG systems.