A Transformerless Medium Voltage Multiphase Motor Drive System
AbstractA multiphase motor has several major advantages, such as high reliability, fault tolerance, and high power density. It is a critical issue to develop a reliable and efficient multiphase motor drive system. In this paper, a transformerless voltage source converter-based drive system for a medium-voltage (MV) multiphase motor is proposed. This drive converter employs cascaded H-bridge rectifiers loaded by H-bridge inverters as the interface between the grid and multiphase motor. The cascaded H-bridge rectifier technique makes the drive system able to be directly connected to the MV grid without the phase-shifting transformer because it can offset the voltage level gap between the MV grid and the semiconductor devices, provide near-sinusoidal AC terminal voltages without filters, and draw sinusoidal line current from the grid. Based on a digital signal processor (DSP), a complete improved Phase Disposition Pulse Width Modulation (PD-PWM) method is developed to ensure the individual DC-link capacitor voltage balancing for enhancing the controllability and limiting the voltage and power stress on the H-bridge cells. A downscaled prototype is designed and developed based on a nine-phase motor. The experimental results verify the excellent performances of the proposed drive system and control strategy in steady-state and variant-frequency startup operations. View Full-Text
Share & Cite This Article
Wang, D.; Yang, J.; Chen, Z.; Mao, C.; Lu, J. A Transformerless Medium Voltage Multiphase Motor Drive System. Energies 2016, 9, 323.
Wang D, Yang J, Chen Z, Mao C, Lu J. A Transformerless Medium Voltage Multiphase Motor Drive System. Energies. 2016; 9(5):323.Chicago/Turabian Style
Wang, Dan; Yang, Jiawei; Chen, Zhu; Mao, Chengxiong; Lu, Jiming. 2016. "A Transformerless Medium Voltage Multiphase Motor Drive System." Energies 9, no. 5: 323.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.