AC converter, AC converting method, and storage medium for converting an AC voltage with a relatively high frequency into an AC voltage with a relatively low frequency

摘要

An AC converter includes: a switching section, which converts the input AC voltage in response to a control signal and which outputs the converted voltage to a phase that has been selected in accordance with the control signal; a filter section, which filters out high frequency components from the converted voltage, thereby converting the converted voltage into the output AC voltage; and a switching control section, which performs a pulse density modulation on a phase-by-phase basis and in response to a reference signal with the frequency f1, which is associated with the output AC voltage of each phase, synchronously with a zero cross of the input AC voltage, thereby generating the control signal according a pulse generation status by the pulse density modulation and the polarity of the input AC voltage and sending out the control signal to the switching section.