New Methods for Harmonic Reduction in T. C. R. by Sequence Control of Transformer Taps

Thyristor controlled static compensators consist of two basic schemes, TCR and TSC. Owing to the discontinuous current in TCR, current harmonics are generated in the supply system. This paper introduces two methods for the reduction of these harmonics. On the basis of the coordination or uncoordination of turn ratios with harmonic reduction levels, each method is described in two alternative schemes. By using either one of these methods, the magnitude of harmonics may be reduced and their undesirable effects in power systems minimized.