Abstract: The invention provides a multi-level inverter control device that is capable of reducing loss of a switching element of a maximum current phase that occurs in an extremely low speed region or at zero frequency. The control device has a maximum current phase selector 52 configured to select a maximum current phase whose current amplitude is a maximum on the basis of current detected values or current command values of a three-phase N-level inverter (N is odd number of three or more); a subtractor 54U, 54V, 54W configured to subtract a voltage command value of a selected maximum current phase from each of the voltage command values of the three phases of the inverter; and a switching signal generator 55 configured to compare each of subtracted voltage command values of the three phases with the (N?1) carrier signals and generate a switching signal of each switching element of the inverter.

Abstract: The invention provides a multi-level inverter control device that is capable of reducing loss of a switching element of a maximum current phase that occurs in an extremely low speed region or at zero frequency. The control device has a maximum current phase selector 52 configured to select a maximum current phase whose current amplitude is a maximum on the basis of current detected values or current command values of a three-phase N-level inverter (N is odd number of three or more); a subtractor 54U, 54V, 54W configured to subtract a voltage command value of a selected maximum current phase from each of the voltage command values of the three phases of the inverter; and a switching signal generator 55 configured to compare each of subtracted voltage command values of the three phases with the (N?1) carrier signals and generate a switching signal of each switching element of the inverter.