A flyback DCM DC-AC converter for PV applications
A flyback DCM DC-AC converter for PV applications
复制标题
DOI：
10.1109/aicera-icmicr.2013.6576018
复制
发表时间：
2013-06
期刊：
影响因子：
--
通讯作者：
L. K. Johny;T. Sebastian
中科院分区：
文献类型：
--
作者：
L. K. Johny;T. Sebastian
展开式反激式转换器在光伏应用中很常见。本文提出了另一种无中心抽头的拓扑结构，改善了负载电压的波形。通过避免反激变压器的中心抽头，可以获得输出中没有任何直流分量的更加对称的波形。这进一步提高了变压器利用率 (TUF)，并且各个组件之间的电压应力也降低了。反激变压器的存在通过在光伏板侧和交流中性点上提供双重接地，进一步避免了太阳能板中TCO腐蚀和漏电流的问题。由于采用展开式逆变器，在整个操作过程中只有一个开关以高频操作，因此开关损耗也降低了。 DCM 操作是首选，因为 CCM 模式下电流波形会失真，这反过来又需要额外的内部电流整形环路以及变压器绕组中的电压尖峰。详细讨论了 DCM 模式下转换器的设计和分析。对用于 DCM 操作的无电流环的简单闭环控制方案进行了仿真并分析了结果。
An unfolding type Flyback converter is common for PV applications. This paper proposes another topology without centre tapping which improves the wave shape of the load voltage. By avoiding centre tapping of the Flyback transformer, a more symmetrical waveform without any dc component in the output is obtained. This further improves Transformer Utilization Factor (TUF) and the voltage stress across various components is also reduced. The presence of Flyback Transformer further avoids the problems of TCO corrosion in solar panel and the leakage current by providing double grounding on the PV panel side and ac neutral. Due to unfolding type inverter, switching losses are also reduced since only one switch is operated at high frequency during the entire operation. DCM operation is preferred due distortion of current waveform in CCM mode which in turn requires an additional inner current shaping loop and also voltage spikes in the transformer winding. Design and analysis of the proposed converter in DCM mode is discussed in detail. A simple closed loop control scheme without current loop for DCM operation is simulated and results are analysed.