Patent ID: 8035334
Filing Date: 2011-10-11
Classification: H02M,H02P

Abstract:
1. An electric power converter that includes an electric-power conversion unit that generates an AC power to be supplied to an AC load in accordance with an AC voltage command input thereto, a voltage-command calculation unit that calculates an AC voltage command with a frequency to be applied to the electric-power conversion unit, and a current detection unit that obtains an output current that is a current component in the AC power that the electric-power conversion unit supplies to the AC load, the electric power converter comprising: a voltage-command correction unit that is provided between the electric-power conversion unit and the voltage-command calculation unit, and that calculates, based on a voltage error caused by a dead time in the electric-power conversion unit, a correction voltage to correct the AC voltage command that the voltage-command calculation unit has obtained, adds the correction voltage to the AC voltage command that the voltage-command calculation unit has obtained, and applies the AC voltage command to the electric-power conversion unit, wherein the voltage-command calculation unit provides a predetermined current range including a zero level for the output current, and, at a first clock time when a value of the output current enters from outside to inside of the current range, obtains a zero cross timing of the output current using the first clock time and the frequency, and sets the zero cross timing as a clock time for switching a polarity of the correction voltage.