NEW TRENDS IN ACTIVE-FILTERS FOR POWER CONDITIONING

Attention has been paid to active filters for power conditioning which provide the following multifunctions: reactive power compensation, ha rmonic compensation, flicker/imbalance compensation, and/or voltage re gulation. Active filters in a range of 50 kVA-60 MVA have been practic ally installed in Japan. Ln the near future, the term ''active filters '' will have a much wider meaning than it did in the 1970's. For insta nce, active filters intended for harmonic solutions are expanding thei r functions from harmonic compensation of nonlinear loads into harmoni c isolation between utilities and consumers, and harmonic damping thro ughout power distribution systems. This paper presents the present sta tus of active filters based on state-of-the-art power electronics tech nology. and their future prospects and directions toward the 21st cent ury, including the personal views and expectations of the author.