Three-phase controlled rectifiers have a wide range of applications, from small rectifiers to large high voltage direct current (HVDC) transmission systems. They can be categorized into line-commutated controlled rectifiers and force-commutated pulse width modulated (PWM) rectifiers. To control the load voltage, the half-wave rectifier uses three common-cathode thyristor arrangement. The larger rating of the secondary with respect to primary is because the secondary carries a dc component inside the windings. Furthermore, the transformer is oversized because the circulation of current harmonics does not generate active power. Parallel connection via interphase transformers permits the implementation of rectifiers for high current applications. A common solution for harmonic reduction is through the connection of passive filters, which are tuned to trap a particular harmonic frequency. Once the stability problems have been solved and the sinusoidal current template has been generated, a modulation method will be required to produce the PWM pattern for the power valves. The additional advantages of force-commutated rectifiers with respect to line-commutated rectifiers, make them better candidates for industrial requirements.