Question 15/V - Magnitudes of harmonics in power and traction lines and
methods to reduce their effects
(Continuation of Question 15/V, 1985-1988)

Study of the characteristics of harmonic currents circulating either in
power lines or traction lines and the methods to reduce the effects of
these currents on telecommunications circuits.

Note 1 - The study should include, for both a.c. and d.c. cases:

- possibility to reduce the level of harmonic currents circulating
in power lines and traction lines;

-the possibility to have some recommendation for the power and traction
organizations or companies to limit the equivalent disturbing currents
to reasonable values;

-specific arrangements enabling a reduction to be made in the noise
appearing in the telecommunication network;

- calculation of the longitudinal and transverse voltages appearing in
telecommunication circuits exposed to induction from these lines.

-methods to measure harmonic currents and voltages;

-propagation (including resonance effects) of harmonic currents and
voltages in power and traction lines.

Note 2 - Account should be taken of the information on Question 15/V
contained in the following documents:

- CCITT Contributions COM V-11, 28, 55, 56 and 78 (1977-1980)

- CCITT Contributions COM V-3, 17 and 25 (1981-1984)

Note 3 - The study of this Question involves close collaboration with
UIC, CIGRE and other organizations and the Special Rapporteur will act
as the representative of CCITT on these matters.