Unified Impedance Model of Grid-Connected Voltage-Source Converters
Unified Impedance Model of Grid-Connected Voltage-Source Converters
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DOI：
10.1109/tpel.2017.2684906
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发表时间：
2018-02
影响因子：
6.7
通讯作者：
Xiongfei Wang;L. Harnefors;F. Blaabjerg
中科院分区：
文献类型：
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作者：
Xiongfei Wang;L. Harnefors;F. Blaabjerg
提出了一种统一的电压源型并网变流器阻抗模型，用于分析锁相环（PLL）和电流控制的动态影响。通过复传递函数和复空间矢量，首次明确地揭示了不同域阻抗模型之间的数学关系。然后提出了一种稳态（αβ-）框架阻抗模型，该模型不仅预测了PLL的稳定性影响，而且还揭示了其频率耦合效应。此外，从结构上比较了锁相环在旋转（dq-）坐标系和静止（αβ-）坐标系下对电流控制的阻抗整形效果。接下来介绍了三相并网变流器的频域案例研究，并随后在时域仿真和实验测试中进行了验证。实测结果与理论分析结果的相关性验证了静止框架阻抗模型的有效性。
This paper proposes a unified impedance model of grid-connected voltage-source converters for analyzing dynamic influences of the phase-locked loop (PLL) and current control. The mathematical relations between the impedance models in the different domains are first explicitly revealed by means of complex transfer functions and complex space vectors. A stationary (αβ-) frame impedance model is then proposed, which not only predicts the stability impact of the PLL, but also reveals its frequency coupling effect. Furthermore, the impedance shaping effects of the PLL on the current control in the rotating (dq-) frame and the stationary ( αβ-) frame are structurally comapred. The frequency-domain case studies on a three-phase grid-connected converter are next presented, and subsequently validated in time-domain simulations and experimental tests. The close correlations between the measured results and theoretical analysis confirm the effectiveness of the stationary-frame impedance model.