Abstract:
A simple on-line compensation scheme to compensate the reactive, hannonic and
sub-hannonic components of line current is proposed in this thesis. The on-line
compensation scheme is based on the fact that if a current of equal amplitude but
180 degrees out of phase with respect to the reactive, hannonic and sub-hannonic
components is injected in the line then these components will be eliminated. Aimed
toward this scheme a closed loop feedback control circuit has been proposed. to
estimate the combined waveshape of the reactive, hannonic and sub-hannonic
components of line current. The approxjmation of this estimated wave .by some
available functions such as pulse width modulated wave and the stepwise function
using power electronic switching circuit is also studied in this work. The study
reveals that the compensation using step-wise approximation provides better.
performance than the approximation using pulse width modulated. wave. This
work proposes a power electronic switching scheme using superconducting magnet
energy storage (SMES) to inject current in the line based on the estimated wave
and step-wise approximation. to compensate the reactive, hannonic and subhannonic
components of line current. This thesis also includes the performance
study of the proposed switching scheme using computer simulation program.
