Suppression of line voltage related distortion in current controlled grid connected inverters
Suppression of line voltage related distortion in current controlled grid connected inverters
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DOI：
10.1109/tpel.2005.857557
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发表时间：
2005-11
影响因子：
6.7
通讯作者：
T. Abeyasekera;C. M. Johnson;D. Atkinson;M. Armstrong
中科院分区：
文献类型：
--
作者：
T. Abeyasekera;C. M. Johnson;D. Atkinson;M. Armstrong
通过理论和实验相结合的方法，研究了不同控制策略对逆变器接入畸变电网后产生的低阶电流谐波畸变水平的影响。基于谐波阻抗的概念，详细的理论分析建立了电感电流反馈与输出电流反馈相对于逆变器电能质量的适用性。采用L-C-L输出滤波器的专用500w三电平半桥逆变器的实验结果验证了电感电流作为反馈变量的有效性，产生的输出电流总谐波失真（THD）比使用输出电流反馈实现的低29%左右。提出了一种前馈电网电压干扰抑制方案，以进一步降低低阶电流谐波畸变水平。采用电感电流反馈和优化的前馈干扰抑制的逆变器的结果显示，满负荷时的THD仅为3%，与采用输出电流反馈和无前馈补偿的相同逆变器相比，THD提高了约53%。在整个负载范围内，THD也得到了显著改善。结论是，使用电感电流反馈和前馈电压干扰抑制是提高输出电流质量的成本-效果机制。
The influence of selected control strategies on the level of low-order current harmonic distortion generated by an inverter connected to a distorted grid is investigated through a combination of theoretical and experimental studies. A detailed theoretical analysis, based on the concept of harmonic impedance, establishes the suitability of inductor current feedback versus output current feedback with respect to inverter power quality. Experimental results, obtained from a purpose-built 500-W, three-level, half-bridge inverter with an L-C-L output filter, verify the efficacy of inductor current as the feedback variable, yielding an output current total harmonic distortion (THD) some 29% lower than that achieved using output current feedback. A feed-forward grid voltage disturbance rejection scheme is proposed as a means to further reduce the level of low-order current harmonic distortion. Results obtained from an inverter with inductor current feedback and optimized feed-forward disturbance rejection show a THD of just 3% at full-load, representing an improvement of some 53% on the same inverter with output current feedback and no feed-forward compensation. Significant improvements in THD were also achieved across the entire load range. It is concluded that the use of inductor current feedback and feed-forward voltage disturbance rejection represent cost-effect mechanisms for achieving improved output current quality.