Zero-Sequence Circulating Current Reduction Method for Parallel HEPWM Inverters Between AC Bus and DC Bus
Zero-Sequence Circulating Current Reduction Method for Parallel HEPWM Inverters Between AC Bus and DC Bus
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DOI：
10.1109/tie.2011.2106102
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发表时间：
2012
影响因子：
7.7
通讯作者：
Tsung-Po Chen
中科院分区：
文献类型：
--
作者：
Tsung-Po Chen
提出了一种实时减小并联消谐脉宽调制（HEPWM）逆变器环流的方法。HEPWM技术通常用于大容量逆变器。例如，在混合微电网中，逆变器用于在直流和交流总线之间传输功率。如果逆变器并联运行，则可以建立零序通路，零序环流将在逆变器之间循环。所提出的方法安装一个级联零矢量控制系统后，传统的三相HEPWM调制器。建议零矢量控制系统可以禁用时，零序环流小，以节省开关损耗，而它可以启用时，零序环流变得很大。所提出的方法不影响HEPWM逆变器的线间电压波形，它可以很容易地启用/禁用零矢量控制系统，以提供无扰动传输。与传统的HEPWM与零序谐波消除相比，所提出的方法可以提供额外的15%的调制指数范围。仿真和实验结果验证了该方法的有效性。
In this paper, a real-time circulating current reduction method for parallel harmonic-elimination pulsewidth modulation (HEPWM) inverters is proposed. HEPWM techniques are often used in high-capacity inverters. For instance, in a hybrid microgrid, the inverters are employed to transfer power between the dc and ac buses. If the inverters are in parallel operation, the zero-sequence path can be established, and the zero-sequence circulating current will circulate among the inverters. The proposed method installs a cascade null-vector control system behind the conventional three-phase HEPWM modulator. The proposed null-vector control system can be disabled to save switching losses when the zero-sequence circulating current is small, whereas it can be enabled when the zero-sequence circulating current becomes large. The proposed method does not affect the line-to-line voltage waveforms of HEPWM inverters, and it can easily enable/disable the null-vector control system to provide bumpless transfer. Compared with the conventional HEPWM with zero-sequence harmonics elimination, the proposed method can provide an extra 15% modulation index range. Results that were obtained from both simulation and experiments confirmed the performance and effectiveness of the proposed method.