AC/DC converter line side harmonics in transient and steady state

The paper analyses voltage and current harmonics generated by two types of AC/DC power converters-standard or line-commutated, and novel PWM controlled. Special consideration is given to the analysis of harmonics in transient states, which are usually neglected. Results show a significant increase of both current and voltage harmonics during transient-states. Their values are compared with harmonic limiting standard VDE 106 (Germany)-both short and long term limits are exceeded during transient-states. This phenomenon may be a source of unwanted negative effects, especially for DC motor drives with long transient-states, so it must be taken into account when harmonic minimization equipment is designed.