A PWM controller includes a sine wave calculator to generate a sine wave signal according to a frequency command value, a first counter to generate a first triangular wave carrier signal, and a comparator to compare the sine wave signal with the first triangular wave carrier signal, generate a PWM signal, and supply the PWM signal to a power converter. The PWM controller further includes a second counter to generate a second triangular wave carrier signal that is π rad behind the first triangular wave carrier signal, a carrier number calculator to calculate a carrier number based on a multiplication number, and a carrier control unit to switch the first triangular wave carrier signal and the second triangular wave carrier signal based on the carrier number, to supply the triangular wave carrier signal to the comparator.