A New DC-AC Interconnected Modular Multilevel Converter for Multiple Applications

Abstract

This seminar highlights a new high-power density Interconnected Modular Multilevel Converter (IMMC) with sinusoidal output voltage for multiple applications. The proposed converter utilizes wide band gap devices at a high switching frequency to achieve compact size/weight/volume. The proposed converter is modular in construction, employs high frequency L-C components and can be stacked for voltage sharing. The IMMC is proposed for motor drives applications due to the following advantages: sinusoidal output with adjustable voltage and frequency (v/f), no acoustic noise, low EMI and absence of dv/dt related issues due to long motor leads. Two design examples for low voltage drives using Gallium Nitride (GaN) devices and medium voltage drives using Silicon Carbide (SiC) are discussed in the seminar.The proposed converter is also evaluated for solar micro-inverter applications due to its compact size and the high-quality output. The proposed system connects the inverter to the PV solar panel through a flyback converter for stepping up the voltage to the grid level, isolation and Maximum Power Point Tracking (MPPT). The proposed inverter eliminates the need for a bulky grid-tie inductor or complex LCL filter. The power can be injected to the grid using a small iron-core inductor due to the sinusoidal nature of the output voltage. A grid-tie control using Fictive Axis Emulation (FAE) is implemented on the converter to optimize the power injected to the grid.

Brief Biography

Ahmed Allehyani received the B.Sc. degree from King Abdulaziz University, Jeddah, Saudi Arabia in 2012, the M.Sc. from the University of Southern California, Los Angeles, CA, USA in 2015 and the PhD from Texas A&M University, College Station, Tx, USA in 2018. He worked for the transmission department at the Saudi Electricity Company, Jeddah, Saudi Arabia as a project engineer in 2012. He has been a teaching assistant in the Electrical Engineering department at the University of Jeddah since 2015. He is currently an Assistant Professor at the University of Jedd. His research interests include multilevel converters, high power density converters, wide band gap devices, AC motor drives, AC-DC rectifiers, switched capacitor converters, switching power supplies, Renewable Energy utility power interface, Solar PV desalination, Electric Vehicles integration, High voltage DC transmission (HVDC), Medium Voltage Direct Current (MVDC) Grid, Flexible AC transmission systems, power system dynamics and power system planning.