PROJECT TITLE :

Medium-Voltage Vector Control Induction Motor Drive at Zero Frequency Using Modular Multilevel Converter - 2017

ABSTRACT:

Conventional modular multilevel converter (MMC) has severe limitation to control at low frequency for the application of variable-speed induction motor drive. Fluctuation of submodule (SM) capacitor voltage will increase rapidly as the motor speed decreases with rated torque. Finally, it becomes impractical to operate the motor at zero frequency. Recently, MMC-primarily based medium voltage induction motor drive has been proposed to tackle this problem without extra circulating current. However, it does not solve the problem near zero frequency with nonzero motor torque. This paper proposes new method to unravel this downside of high peak-to-peak voltage ripple of SM capacitor in the slightest degree frequencies as well as zero frequency. Vector control strategy for induction motor is adopted here to possess correct management of torque near zero frequency. 1st, the problem of low-frequency operation is analyzed. Then, the answer is proposed analytically. The proposed control technique and overall performance of the drive have been verified through experimental results.