Title :
Multilevel Current Source Inverters with Phase Shifted Trapezoidal PWM
Author_Institution :
Dept. of Electr. & Comput. Eng., Ryerson Univ., Toronto, Ont.
Abstract :
A 7-level current source inverter (CSI) is proposed for high-power applications. The inverter topology consists of three bridge current source inverters whose outputs are connected in parallel for a large induction motor. The multilevel inverter is fed by an 18-pulse SCR rectifier with three isolated outputs for the reduction of supply-side current THD and the elimination of possible circulating current among the inverters. A phase-shifted trapezoidal PWM (TPWM) scheme is proposed for the inverter to generate multiple current levels. Optimal phase angles are investigated for the reduction of inverter current THD and weighted THD (WTHD). Similar to multilevel voltage source inverters, the multilevel CSI can produce motor-friendly current and voltage waveforms with limited switching frequencies, which is a desirable feature for large motor drives
Keywords :
PWM invertors; harmonic distortion; induction motor drives; network topology; phase shifters; rectifying circuits; switching convertors; THD; induction motor drives; inverter topology; multilevel bridge current source inverters; phase-shifted trapezoidal PWM scheme; switching frequencies; voltage source inverters; Bridge circuits; Current supplies; Induction generators; Induction motors; Pulse width modulation inverters; Rectifiers; Switching frequency; Thyristors; Topology; Voltage;
Conference_Titel :
Power Electronics Specialists Conference, 2005. PESC '05. IEEE 36th
Conference_Location :
Recife
Print_ISBN :
0-7803-9033-4
DOI :
10.1109/PESC.2005.1581990
