Details

Autor(en) / Beteiligte

• Liu, Wei-Zeng
• Zhang, Xin-Tao
• Shao, Shuai

Titel

Analysis and Compensation of Zero-current Clamping Phenomenon in Grid-connected Photovoltaic Inverters

Ist Teil von

• Dian li dian zi ji shu, 2012-07, Vol.46 (7), p.1-3

Erscheinungsjahr

2012

Beschreibungen/Notizen

• A detailed analysis of the mechanism responsible for the zero-current clamping (ZCC) phenomenon in grid-connected photovoltaic inverters is presented, and the boundaries of the ZCC region are theoretically predicted. It is shown that the dead-time will cause the current distortion at the zero-crossing point, and the switching turn-on delay time within every switching cycle can also cause an additional volt-second loss, and leads to grid-connected current waveform distortion near the zero-crossing point. To compensate this additional volt-second loss,a two-pulse compensation approach is proposed, in which an extra fixed time pulse is imposed on the original switching gating signals based on the traditional unipolar SPWM strategy during the zero-current clamping time. And thus, all the volt-second losses are compensated accurately and the clamping phenomenon of zero-current crossing point is eliminated. A 10 kW grid-connected PV inverter is measured to test the effectiveness of the proposed compensation approac