摘要 |
An AC converter includes: a switching section 101, 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 104, 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 103, which performs a pulse density modulation on a phase-by-phase basis and in response to a reference signal with the frequency fl, 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 101. |