| Abstract |
Two new schemes of low-distorting three-phase diode-bridge rectifiers with capacitive smoothing of the output voltage are proposed, analyzed, and verified. The harmonic distortion reduction technique proposed is based on optimum injection of the third-, sixth-, and ninth-harmonic ripple currents. To improve the efficiency, the third-harmonic ripple power is re-rectified using a low-power auxiliary AC-DC converter. Function of the sixth-harmonic current branch is, firstly, to compensate inductive current component of the smoothing inductors and, secondly, to induce a small active sixth-harmonic current component that enables to reduce the total harmonic distortion THD about 2\%. The ninth-harmonic current branch enables a further reduction of the THD about 1.5\%. In proposed schemes, low values of the THD hold in wide range of the load and supply-voltage variation. |
