A Shunt Active Power Filter

Harmonic injection into the power system has become more and more serious due to the wide use of power electronics equipment. Because of inherent limitations existed in the conventional passive filters, application of the active power filter (APF) is becoming a hot spot recently. The paper investigates the problem of three-phase and three-line shunt APF with simulation and experiment.The mathematic model of three-phase and three-line shunt APF in different kind of coordinate is set up. This helps for the research on APF thoroughly.The paper thoroughly analyses the harmonic detection based on the instantaneous reactive power theory and specially designs the low pass filter (LPF) which is used in the harmonic detection.The basic principle of triangle PWM and SVPWM is introduced and their difference and relation are also analyzed. The general PI control and compensatory PI control in three-phase stator coordinate and the decoupled PI control in two-phase rotor coordinate are compared with simulation. The DC voltage control of shunt APF is introduced and point out that the APF run as a PWM rectifier is the hypostasis of it.An experimental device of a three-phase and three-line shunt APF is designed with TMS320F2407A DSP as the main controller, Each part of the software and hardware on the experimental device is discussed in detail, and the results is given.