Analysis of D-Q Small-Signal Impedance of Grid-Tied Inverters
Analysis of D-Q Small-Signal Impedance of Grid-Tied Inverters
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DOI：
10.1109/tpel.2015.2398192
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发表时间：
2016
影响因子：
6.7
通讯作者：
B. Wen;D. Boroyevich;R. Burgos;P. Mattavelli;Zhiyu Shen
中科院分区：
文献类型：
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作者：
B. Wen;D. Boroyevich;R. Burgos;P. Mattavelli;Zhiyu Shen
分析了同步参考坐标系下带反馈控制和锁相环的三相并网逆变器的小信号阻抗。结果揭示了三相并网逆变器的一个有趣而重要的特性，即其q-q通道阻抗表现为负增量电阻。此外，本文表明，这种行为是电网同步的结果，其中PLL的带宽决定了电阻行为的频率范围，逆变器的额定功率决定了电阻的大小。先进的PLL、电流和功率控制策略不会改变这一特性。一个例子表明，在弱电网条件下，PLL带宽的变化可能导致逆变器系统的不稳定条件，作为这种行为的结果。谐波谐振和不稳定性问题可以使用所提出的阻抗模型进行分析。仿真和实验测量验证了分析。
This paper analyzes the small-signal impedance of three-phase grid-tied inverters with feedback control and phase-locked loop (PLL) in the synchronous reference (d-q) frame. The result unveils an interesting and important feature of three-phase grid-tied inverters - namely, that its q-q channel impedance behaves as a negative incremental resistor. Moreover, this paper shows that this behavior is a consequence of grid synchronization, where the bandwidth of the PLL determines the frequency range of the resistor behavior, and the power rating of the inverter determines the magnitude of the resistor. Advanced PLL, current, and power control strategies do not change this feature. An example shows that under weak grid conditions, a change of the PLL bandwidth could lead the inverter system to unstable conditions as a result of this behavior. Harmonic resonance and instability issues can be analyzed using the proposed impedance model. Simulation and experimental measurements verify the analysis.