PARALLEL-CONNECTED DIODE-CLAMPED FIVE-LEVEL PWM INVERTER
Author      : A.MANI VAASAGAM, M.NIRRANJAN (PRE FINAL YEAR) Dept         :  EEE College     :   MOOKAMBIGAI COLLEGE OF ENGINEERING File type   :  DOC Publish     :
ABSTRACT:   Multilevel PWM inverters, including five-level ones, have significant advantages over conventional one because of the capability of operating the motor with nearly sinusoidal current waveforms and higher output voltages. Consequently, interest in actual applications is increasing. In discussing practical applications, still larger capacity inverters are also anticipated, such as those for large ac motor drives. In order to increase the capacity of an inverter, connection in parallel is an effective method at present case. In general, a multilevel inverter could also be obtained by connecting the inverters in parallel with different phases for the carriers, and certain techniques and control methods should be considered when doing this. In high-power applications for instance, the carriers should be synchronized to the modulating sinusoidal waves. In addition, each three phase waveform should be built in a quarter-wave symmetry as well as a half-wave symmetry.