说明：  Passive filter and active filter are two ahnative strategi- es to suppress harmonics in the electrical distribution system. Pas- sive filter is dc and efficient but it may cause the resonimce problem. Active film has become a mature tecblogy recently and will considerably be generalized in the near fuhrre. In this paper, a laboratmy which consists of 110 KVA six-pulse rectifier loads, one 50 KVA active filter, and six-step 54 KVAR passive f~ has been monic current sou~ce are mvestigeted by expeaiment and simulation. The passive lilter and active film are applied to dif€ erent harmonic sources by turns and the harmonics aAer compensation are md. It is observed fkom the experiment measurements, application of passive filter or active filter to harmonic voltage source will amp@ the harmonic currents at the load side and larger capacity of filter is needed.