POWER CONVERSION DEVICE, POWER CONVERSION METHOD, MOTOR SYSTEM, AND TWO-PHASE INDUCTION MOTOR

摘要

Provided is a power conversion method that is excellent in efficiency and reliability and used for converting a single-phase AC voltage to a two-phase AC voltage. An input voltage (in), which is a single-phase AC voltage, is received, and a first target voltage (ref1) and a second target voltage (ref2) are specified that represent the sequential target values of the respective first and second phases of output voltages (out1, out2) which are a two-phase AC voltage. In periods (T2, T3, T5, T6) during which the instantaneous value of the absolute value of the input voltage (in) is larger than the instantaneous value of the absolute value of the first target voltage (ref1), a pair of input terminals and a pair of first output terminals are periodically connected to and disconnected from each other with a duty ratio according to the ratio |ref1/in|. In periods (S2, S3, S5, S6) during which the instantaneous value of the absolute value of the input voltage (in) is larger than the instantaneous value of the absolute value of the second target voltage (ref2), the pair of input terminals and a pair of second output terminals are periodically connected to and disconnected from each other with a duty ratio according to the ratio |ref2/in|.