Reactive Power Compensation using FC-TCR

Abstract

Industrial loads are source of disturbances to power system due to more and more non-linearity. Apart from their good functional properties, they are characterized by negative impact on the quality of power. Such loads will cause distortion of supply voltage, unbalance phase loadings, fluctuations, higher neutral current etc. Depending on the load type, such disturbances may occur separately or concurrently. These disturbances are propagated through distribution systems to other users' networks, impair operating conditions of equipment and, in extreme cases, prevent operation of electrical equipment sensitive to such disturbances.The adverse impact of non-linear loads on a power system can be mitigated by means of compensation equipment like fixed capacitor (FC), thyristor controlled reactor (TCR) - FC/TCR. The purpose of FC-TCR compensator is compensation of the fundamental component of the reactive power and filtering selected current harmonics. The goal is the minimization of the RMS and THD values of the line current by controlling the ring angle value of the TCR branch. For simulation purpose loads are represented by its equivalent R-L circuits. Optimum algorithm is applied in each half cycle of the voltage source, and optimum ring angles are obtained satisfying the condition of minimum RMS value of line current such that reactive power is compensated and power factor is maintain near to unity.