Study on the current detecting method for reactive power and harmonic of the three-phase circuits

Based on the active current separation, a method for direct-detecting the harmonic and reactive current have been applied to three-phase circuits. A three-phase current detection system was designed. The fundamental active component of each phase current could be extracted by using the system. The value of compensation is the sum of the reactive and harmonics current. When the three-phase voltage is asymmetric, an accurate detection results can be obtained. Compared with the detection method based on instantaneous reactive power theory, the detection system proposed is simpler and lower-cost. The theoretical analysis and simulation experiment illustrate the effectiveness and correctness of the system proposed.