A power conversion control method including: generating PWM signals that are output to a first and a second single-phase or multiphase bridge circuit connected in parallel to a DC power supply and respectively connected to inductive loads (7,8); and selecting one of a first carrier wave (Ca1_X) for outputting the PWM signal to the first bridge circuit and a second carrier wave (Ca2_X) with a predetermined phase difference (φ) to the first carrier wave (Ca1_X), and based on the carrier wave (CaIn_pre_X) selected, performing switching control of the carrier wave (CaIn_X) for outputting the PWM signal to the second bridge circuit, characterized in that the power conversion control method further comprises: in the switching control of the carrier wave (CaIn_X), calculating a pre-switching pulse time (Δta_x) being a time from a first conductive state switching timing being a conductive state switching timing of the second bridge circuit immediately before a predetermined carrier wave switching timing, to the carrier wave switching timing; calculating a post-switching pulse time (Δtb_x) being a time from the carrier wave switching timing to a second conductive state switching timing being an initial conductive state switching timing after the carrier wave switching timing; when a conductive state of the second bridge circuit is not switched at the carrier wave switching timing, determining that switching of the carrier wave is disabled when a sum (Δt_x) of the pre-switching pulse time (Δta_x) and the post-switching pulse time (Δtb_x) is less than a predetermined pulse time sum threshold value; and when the conductive state of the second bridge circuit is switched at the carrier wave switching timing, determining that the switching of the carrier wave is disabled when the pre-switching pulse time (Δta_x) or the post-switching pulse time (Δtb_x) is less than a predetermined pulse time threshold value. generating PWM signals that are output to a first and a second single-phase or multiphase bridge circuit connected in parallel to a DC power supply and respectively connected to inductive loads (7,8); and selecting one of a first carrier wave (Ca1_X) for outputting the PWM signal to the first bridge circuit and a second carrier wave (Ca2_X) with a predetermined phase difference (φ) to the first carrier wave (Ca1_X), and based on the carrier wave (CaIn_pre_X) selected, performing switching control of the carrier wave (CaIn_X) for outputting the PWM signal to the second bridge circuit, characterized in that the power conversion control method further comprises: in the switching control of the carrier wave (CaIn_X), calculating a pre-switching pulse time (Δta_x) being a time from a first conductive state switching timing being a conductive state switching timing of the second bridge circuit immediately before a predetermined carrier wave switching timing, to the carrier wave switching timing; calculating a post-switching pulse time (Δtb_x) being a time from the carrier wave switching timing to a second conductive state switching timing being an initial conductive state switching timing after the carrier wave switching timing; when a conductive state of the second bridge circuit is not switched at the carrier wave switching timing, determining that switching of the carrier wave is disabled when a sum (Δt_x) of the pre-switching pulse time (Δta_x) and the post-switching pulse time (Δtb_x) is less than a predetermined pulse time sum threshold value; and when the conductive state of the second bridge circuit is switched at the carrier wave switching timing, determining that the switching of the carrier wave is disabled when the pre-switching pulse time (Δta_x) or the post-switching pulse time (Δtb_x) is less than a predetermined pulse time threshold value. in the switching control of the carrier wave (CaIn_X), calculating a pre-switching pulse time (Δta_x) being a time from a first conductive state switching timing being a conductive state switching timing of the second bridge circuit immediately before a predetermined carrier wave switching timing, to the carrier wave switching timing; calculating a post-switching pulse time (Δtb_x) being a time from the carrier wave switching timing to a second conductive state switching timing being an initial conductive state switching timing after the carrier wave switching timing; when a conductive state of the second bridge circuit is not switched at the carrier wave switching timing, determining that switching of the carrier wave is disabled when a sum (Δt_x) of the pre-switching pulse time (Δta_x) and the post-switching pulse time (Δtb_x) is less than a predetermined pulse time sum threshold value; and when the conductive state of the second bridge circuit is switched at the carrier wave switching timing, determining that the switching of the carrier wave is disabled when the pre-switching pulse time (Δta_x) or the post-switching pulse time (Δtb_x) is less than a predetermined pulse time threshold value.