19-09-2017, 04:10 PM
Reactive power compensation is studied using a fixed capacitor (FC) and a thyristor controlled reactor reactor (TCR). The objective is to minimize the RMS and THD values of the line current by controlling the value of the trip angle of the TCR branch. To achieve this, some changes were required in the conventional architecture of the conventional FC-TCR compensator. We show that the substitution of the reactor by a switch-switched reactor forces the thyristor's firing angle to be small, improving the power factor (PF) and the total harmonic distortion of the line current (THDI). We call this new architecture "fixed thyristor switched reactor with switched commutator and thyristor controlled reactor" (FC-TSR-TCR). In the case of non-sinusoidal voltage supply, the above amounts, PF and THDI, are markedly improved by replacing the fixed capacitor with a fixed LC branch (FLC-TSR-TCR). These changes are also effective with non-linear loads. For the purposes of simulation, the models of FC-TSR-TCR and FLC-TSR-TCR compensators, and the linear and non-linear loads, represented respectively by the RL circuits and the ideal current sources, have been considered. For several illustrative cases, an optimization algorithm is applied to each half-cycle of the voltage source, and optimal values of trip angles are obtained by satisfying the minimum rms value of the line current. PF and THDI are calculated in the cases considered to show the performance of the FLC-TSR-TCR compensator.