Active Damping for Three-Phase PWM Rectifiers With High-Order Line-Side Filters

Active rectifiers interfacing the grid have gained much attention in recent years due to their current control capability that enables the application to exchange a certain range of power at the benefit of low harmonic distortion compared to line commutated converters. Moreover, the amount of active and reactive powers can be arbitrarily chosen within certain limits. These limits as well as the degree of harmonic attenuation is determined by the line-side filter. This paper basically focuses on the current control of active rectifiers incorporating a line-side filter of first-up to third-order degree. Thus, it treats both the current-source converter (CSC) as well as the voltage-source converter (VSC). The basic models of the plant are derived for each case, and important dualities are pointed out. As a conclusion, a recipe for the controller design of particularly CSCs with LC filters and VSCs with LCL filters is proposed.