Integrated voltage current converter and current source inverter drive system for three phase AC machines

This project is focused on developing a current source inverter (CSI) motor drive system that can be used for a variety of electrical vehicle applications. Voltage source inverters (VSIs) were the primary option for most inverter applications. Generally, VSIs have a number of issues such as larger inverter dimensions, shorter lifetime, and higher cost. A VSI requires a large and costly DC bus capacitor, which also contributes to inverter reliability issues. CSIs are the possible solutions to eliminate the aforementioned problems as they do not need a large DC bus capacitor. Instead, they utilize three small AC filter capacitors and one energy storage component (inductor). In addition to the reduced cost and size, CSIs have several other significant advantages compared to VSIs, including increased reliability and dependability, higher and more stable power suitable for changes in the AC motor speed, and greater motor efficiency and lifespan. This report discusses two of the main components in developing a state-of-the-art CSI drive system. First, the design of the voltage-current (V-I) converter or the controlled current source is presented. Second, the development of a three-phase DC/AC CSI inverter is explained. The V-I converter and the CSI were developed separately, they were integrated and tested for motor or generator operations. Both components of the inverter system are designed and developed using the Matlab/Simulink environment. The system includes a motor or generator load, a three-phase inverter incorporating the space-vector Pulse Width Modulation algorithm. All simulation results are analyzed based on the three phase output voltage and current waveforms.