Patent ID: 8395918

Claim:
A method of controlling a converter, said converter including a rectifier circuit for outputting a low potential, a high potential higher than said low potential, and a midpoint potential between said low potential and said high potential, a first capacitor receiving said low potential and said midpoint potential, and a second capacitor connected at a connection point to said first capacitor, and receiving said high potential and said midpoint potential, said rectifier circuit including a three-phase diode bridge for rectifying first, second, and third potentials at second ends of a set of three reactors, respectively, having first ends to which a three-phase voltage is applied, to thereby output said low potential and said high potential, and a switch group for selectively connecting said second ends of said three reactors to said connection point, wherein, when first, second, and third command values that are command values for said first, second, and third potentials, respectively, are in a predetermined range, said switch group connects said second ends corresponding to the respective command values to said connection point, and wherein a range having a predetermined potential width with respect to an AC waveform centered around the command value of said midpoint potential is used as said predetermined range.