Question

Why harmonics are generated in hvdc system?

Answer 1

Harmonics in hvdc cause an increase in the iron and copper losses. Voltage distortion increase losses due to hysteresis and eddy currents and causes overstressing of the insulation material used. The primary effect of power line harmonics in transformer is, thus the additional heat generated.

Answer 2

In this paper, the need for filters used in HVDC systems was discussed. The problem of harmonics

 produced in HVDC systems was given. The method to eliminate the harmonics was discussed in simple

manner. Design criteria for different types of filters were briefed to attract the various minds working,

studying and doing research in HVDC systems. The harmonic indices were also given in this paper to

measure the effect of harmonics in HVDC systems. This paper covers only the basic ideas needed for

design of various types of filters, harmonics indices, Effect of harmonics and reduction of harmonics.

A special attention was also given to the generation and reduction of carrier frequency and RI noise in

HVDC systems. This paper would be helpful for the undergraduate and post graduate students to study

about the basics types of harmonics, effect of harmonics and reduction of harmonics using several types

of filters. It would be helpful to have some ideas for doing their research works and projects in HVDC