1. A New Five-Level Active Neutral-Point-Clamped Converter With Reduced Overvoltages.
- Author
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Burguete, Eduardo, Lopez, Jesus, and Zabaleta, Mikel
- Subjects
- *
SEMICONDUCTORS , *CASCADE converters , *ELECTRIC circuits , *ELECTRIC potential , *ELECTRIC currents - Abstract
The large number of semiconductors typically implemented in multilevel converters generates large stray inductances in their commutation loops. As a consequence, high-voltage overshoots appear in the semiconductors during commutation which may limit the operation of the converter. The paper analyzes these overvoltages in the five-level active neutral-point-clamped (5LANPC) converter, one of the most popular five level converters and employed by ABB in its ACS2000 drive. Experimental results show overvoltages almost three times higher than those corresponding to a two-level converter. In order to overcome this problem, the paper presents a new 5LANPC with the same characteristics (number of semiconductors, output waveform, switching frequency, efficiency, etc.), but with smaller overvoltages. This is achieved by adding some small capacitors to the busbar that behave like lossless snubbers but with a much simpler implementation. The experimental results illustrate the working principle of these capacitors and demonstrate the reduction of the overvoltages. As a result, the new converter can reach a higher output current or speed-up the commutations reducing, therefore, the losses and increasing the efficiency compared with the previous 5LANPC. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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