Optimal interleaving angle determination in multi paralleled converters considering the DC current ripple and grid Current THD

A typical application for parallel connected converters is in multi megawatt wind turbine systems. Manipulating the interleaving angle between the Pulse Width Modulated (PWM) carrier waves of each converter can result in reduced grid and DC link current ripple, thus the passive components from the DC link and grid filter can be minimized. In previous studies the optimization of the interleaving angle for either the grid current Total Harmonic Distortion (THD) or the DC link current ripple has been made. In this study a compromise is made in order to maintain a THD of the grid current in a level that complies with the standards, while in the DC link the current ripple is reduced. The dependency of the grid current THD and the DC link current ripple on the interleaving angle were determined by simulations. The results were also validated on a hardware setup.