A Transformerless Hybrid Active Filter for Integration into a Medium-Voltage Motor Drive with a Passive Front End

다국어 초록 (Multilingual Abstract)

This paper discusses a transformerless hybrid active filter integrated into the 6.6-㎸, 1-㎿ adjustable-speed motor drive having a three-phase diode rectifier at the front end. The hybrid filter consists of an active filter using a threelevel diode-clamped PWM converter rated at 60 ㎸A, and a 250-㎸A passive filter tuned to the 7th-harmonic frequency. They are directly connected in series without transformer. This circuit configuration enables to use 1.2-㎸ IGBTs because the dc voltage of the three-level converter is 1.32 ㎸ (20% of 6.6 ㎸). Voltage-balancing control characterized by superimposing a 6thharmonic zero-sequence voltage on the active-filter voltage reference in each phase is introduced to the three-level converter with triangle-carrier modulation. Experimental waveforms obtained from a 400-V 15-㎾ down-scaled system verify the viability and effectiveness of the proposed hybrid filter, keeping the two dccapacitor voltages balanced well.

목차 (Table of Contents)

• Abstract
• Ⅰ. INTRODUCTION
• Ⅱ. SYSTEM CONFIGURATION
• Ⅲ. CONTROL SYSTEM OF THE ACTIVE FILTER
• Ⅳ. VOLTAGE-BALANCING CONTROL OF THE TWO SPLIT DC CAPACITORS
• Ⅴ. EXPERIMENTAL RESULTS
• Ⅵ. CONCLUSIONS
• REFERENCES