Inductive co-ordination in rural areas

The solution of numerous inductive co-ordination problems involving rural power and communication circuits has indicated that generators, transformers, and other equipment used on rural power lines should be designed to generate as little harmonic current as practicable. Noisy circuits caused by induction from power lines cannot, by any means, be cleared up by the telephone people without the co-operation of the power suppliers. In general, power equipment containing iron in its magnetic circuit generates voltages whose frequencies are multiples or harmonics of the fundamental frequency. The magnitude and frequency of these harmonic voltages depend on the type of magnetic material and the portion of the magnetization curve on which the equipment is operating.