Modelling of a separately excited DC motor supplied by a three-phase bridge rectifier using a complex Fourier series

The presented paper deals with mathematical algorithms of an analytical calculus of an electromagnetic torque ripple of the separately excited DC motor. Assume the motor is supplied by a full controlled threephase thyristors rectifier. To describe non harmonic rectifier output voltage, the complex Fourier series was used. Suppose the motor works with constant rotor speed at steady-state. Two motor operating conditions are discussed. Continuous and discontinuous armature current operations are distinguished. The waveforms of the motor current and electromagnetic torque are calculated.