A process for the power supply of a multi-strand, by means of pulse width modulation controlled electric motor

摘要

The invention relates to a method for power supply of a multi-strand, electronically commutatable, electric motor controlled by pulse width modulation of a dc voltage network (24, 25), in particular for the operation of a motor for the electric power steering of a motor vehicle, with a preferably with a microcontroller constructed control unit (10) for at least two in full bridge circuit (h - circuit) constructed inverter (12, 14, 16) for supplying the phase windings (18, 20, 22) of the motor and with at least one between the dc voltage network and the inverters arranged an intermediate circuit capacitance (26), preferably an electrolytic capacitor, to the transfer of the phase currents (i1, i2, i3) while the current flow intervals of the electronic switch (t1 - t12) of the inverter. In this case, the current loading of the intermediate circuit capacitance is reduced by a clocking of the pulses which are offset in time in such a way for driving the switches (t1, t3, t5, t7; t9, t11) of the inverter (12, 14, 16), that an overlap of the pulses of the phase currents (i1, i2, i3) is avoided or at least reduced.