Patent ID: 8810171
Filing Date: 2014-08-19
Classification: H02P

Abstract:
1. A motor controller, comprising: a power converter that includes a plurality of bridge connected switching elements and that converts incoming direct-current electric power to be supplied to a motor; a switching signal generator that generates at least three phases of switching signals such that the switching elements are driven by an ON/OFF pattern that exhibits a pulse width modulation pattern; and a current detector that is provided on a direct current side of the power converter and that detects direct current information of the direct current side, and that feeds the detected direct current information to the switching signal generator, wherein the switching signal generator includes a determiner that determines a size of an offset voltage contained in the detected direct current information, and a modifier that modifies the detected direct current information based on the size of the offset voltage determined by the determiner, and wherein the determiner calculates the offset voltage by canceling a positive current component by a negative current component contained in the detected direct current information, the direct current information being detected in a first period in which a positive-side switching element of a first phase is ON and positive-side switching elements of a second phase and a third phase are OFF and a second period in which a negative-side switching element of the first phase is ON and negative-side switching elements of the second phase and the third phase are OFF, the first period and the second period being a period in which a motor current flows in the same direction and transmits the calculated offset voltage to the modifier.