Active thermal control for reliability improvement in photovoltaic single‑phase T‑type NPC inverters

Youngjong Ko; Taerim Ryu; Ui-Min Choi

Active thermal control for reliability improvement in photovoltaic single‑phase T‑type NPC inverters

Youngjong Ko

Taerim Ryu

Ui-Min Choi

Vol. 23, No. 5, pp. 850-859, May 2023

10.1007/s43236-023-00626-y

Single-phase T-type inverter

Photovoltaic

Reliability

Power semiconductor

Active thermal control

Abstract

Single-phase T-type neutral point clamped (NPC) inverters have been extensively employed in small scale photovoltaic (PV) systems due to their outstanding power conversion efficiency. However, it is still necessary to further reduce PV energy costs to successfully replace fossil fuels. To do so, the reliability of inverters needs to be improved, which will result in both operation and maintenance cost reductions and the energy production improvement. On the other hand, the T-type NPC inverter suffers from unevenly distributed power losses among power semiconductor devices, which implies that the devices generating the highest losses are quickly aged and fail sooner than other devices. In this context, it is recommended to reduce the thermal stresses of the highest stressed devices. This work proposes a thermally compensated modulation strategy that enables thermal stress reduction. The capability of the proposed method for controlling power losses is theoretically analyzed, and its impact on lifetime is evaluated. Finally, the feasibility of the proposed method is experimentally validated.

Statistics

Show / Hide Statistics

Cumulative Counts from September 30th, 2019
Multiple requests among the same browser session are counted as one view. If you mouse over a chart, the values of data points will be shown.

Cite this article

[IEEE Style]

Y. Ko, T. Ryu, U. Choi, "Active thermal control for reliability improvement in photovoltaic single‑phase T‑type NPC inverters," Journal of Power Electronics, vol. 23, no. 5, pp. 850-859, 2023. DOI: 10.1007/s43236-023-00626-y.

[ACM Style]

Youngjong Ko, Taerim Ryu, and Ui-Min Choi. 2023. Active thermal control for reliability improvement in photovoltaic single‑phase T‑type NPC inverters. Journal of Power Electronics, 23, 5, (2023), 850-859. DOI: 10.1007/s43236-023-00626-y.