| 摘要 |
PCT No. PCT/SE93/00187 Sec. 371 Date Aug. 23, 1994 Sec. 102(e) Date Aug. 23, 1994 PCT Filed Mar. 4, 1993 PCT Pub. No. WO93/18204 PCT Pub. Date Sep. 16, 1993In a metallic pipeline (1) disposed in the ground, voltages may be induced from adjacent transmission lines and cause corrosion. To reduce the risk of corrosion, voltages are induced in the pipeline with the aid of a transformer (8), which voltages counteract the induced voltages. A measuring conductor (2) provides a signal which is a measure of the induced voltage. In a suitable way, this signal controls the amplitude and phase position of a voltage (U1) which is generated by a converter coupling (7) and is applied to the primary winding of the transformer (8). (FIG. 1a) |
