FC + TCR-Type Symmetrical Follow-Up Compensator of the Fundamental Harmonic Reactive Power—Analysis and Experiment

The chapter presents results of analyses, simulations, and experiments concerning a FC + TCR-type symmetrical follow-up compensator of the fundamental harmonic reactive power in which a three-phase bridge rectifier with two additional thyristors (6T + 2T) was used as the adjustable inductive component. The research pertain to the three-phase 6T + 2T bridge rectifier circuit with the neutral wire led out, where selection and application of the appropriate developed thyristor controlling algorithm (introduction of an additional control angle δ) enables current flow outside supply source phases in those instants of time when output voltages of the star rectifiers have instantaneous negative values. The effect of minimization of rms and the reactive power component of the fundamental harmonic of source currents consists in a reduction of reactive load introduced by 6T + 2T bridge rectifier with respect to 6T bridge with the possibility to control it by choosing an appropriate value of angle δ. To obtain a lower content of harmonics in the power grid current, it has been proposed to couple a 5th and 3rd harmonics filter on the converter. Such a converter, equipped with filters with output terminated with a reactor and stabilizing the direct current value at different values of angle δ, can be used as a FC + TCR-type symmetrical follow-up compensator of reactive power. Regulation of reactive power in such a circuit is instantaneous. The paper ends with a presentation of applications developed in LabVIEW programming environment to visualize the principle of operation, take measurements, and results of laboratory research carried out with the compensator.