Research on a Current Direct Control Method

A current direct control is proposed in the paper. The topology structure of a hybrid filtering equipment is presented. The traditional current detecting and controlling method for the structure is discussed. The relationship between the grid current and harmonic suppressing current is educed, which proves that the step of harmonic detection be left out in theory. A current direct control based on the grid current error is proposed, which is simple. It is not necessary to detect harmonic and reactive current. So influence factors on the real time and precision of the filter are reduced. The simulating model of the hybrid filtering equipment is constructed and the new current direct control is applied in the model. The simulating results show that the good performance of harmonic suppression and reactive compensation is obtained with the current direct control.