Patent ID: 8975856
Filing Date: 2015-03-10
Classification: H02P

Abstract:
1. A method of improving efficiency in a three-phase motor ( 40 ) having permanent-magnet excitation, a DC link power supply circuit including a current measuring element ( 56 ), and a control circuit ( 95 ) having an input coupled to an output of said current measuring element ( 56 ) and control outputs (A, B, C) coupled to respective phase windings of said motor, comprising the steps of: a) at a predetermined operating voltage (Û), operating the motor ( b) using said current measuring element to make a first sampling of amplitude of a current flowing to the motor ( c) reducing the amplitude of the voltage (Û) delivered to the motor (S d) making a second sampling of amplitude of the current flowing to the motor ( e) comparing said second measured amplitude value with said first measured amplitude value; f) if a result of said comparing step shows that the current flowing to the motor ( g) if said result of said comparing step shows that the current flowing to the motor (