Motor friendliness of variable frequency drives with output transformer

This paper evaluates the impact of output transformer on the power quality and especially the motor friendliness. A comparison of systems with and without transformer is made and the results are visualized. An output transformer with voltage ratio of 1 is used so that an identical motor is used in both cases for the purpose of easy comparison. The main conclusion is that the presence of an output transformer can positively impact the current and voltage waveform and increase the motor friendliness.

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