Abstract: Provided are hybrid passive power filter and a three-phase power system. The hybrid passive power filter includes: a series passive harmonic isolation unit, a parallel passive filtering unit, and a harmonic load; the series passive harmonic isolation unit has an input terminal electrically connected to a power grid and an output terminal electrically connected to a first terminal of the harmonic load, and the series passive harmonic isolation unit is configured to isolate harmonics; and the parallel passive filtering unit has an input terminal electrically connected to the output terminal of the series passive harmonic isolation unit and an output terminal electrically connected to a second terminal of the harmonic load, and the parallel passive filtering unit is configured to filter out harmonics.

Abstract: Provided is an on-line ice-melting apparatus. The apparatus is configured for melting the ice on a three-phase line. The apparatus includes an adjustable reactor, a grounding transformer, a controller, and an auxiliary circuit. The grounding transformer, the adjustable reactor, the auxiliary circuit, and a line of any phase of the three-phase line form a first control loop. The adjustable reactor includes a working winding, a control winding, and a short-circuit winding. The working winding is connected between the grounding transformer and the auxiliary circuit. The controller is electrically connected to the control winding and the short-circuit winding separately.