MICROSTEP DRIVE UNIT OF FIVE-PHASE STEPPING MOTOR

摘要

PROBLEM TO BE SOLVED: To provide a microstep drive unit of a five-phase stepping motor which can perform microstep drive that is reduced of torque ripples.;SOLUTION: The drive unit of the five-phase stepping motor comprises a five-phase stepping motor 1 in which five pieces of phase windings which are displaced in phase at each electric angle of 72° are annularly connected to one another; a five-phase bridge inverter circuit 2 which is connected to a DC power supply by connecting in parallel five sets of series circuits, each of which is composed of a pair of switching elements which are connected to each other in series and in which each connecting point of the phase winding is connected to each connecting point of the pair of switching elements; and a current control part 7, which detects the current flowing in the inverter circuit by using a detector 4, and controls a current value flowing in the inverter circuit at all times. The drive unit performs pulse-width modulation, by conducting on/off-switching control so that the other switching element of the pair of switching elements is turned off, when one of the switching elements is tuned on; and when the other is turned on, the one is turned off. Also in the drive unit, a voltage waveform for each connecting point of the switching element contains a third-order harmonic components at -7 to -16%.;COPYRIGHT: (C)2009,JPO&INPIT