A single-phase voltage type AC/DC converter, comprising: a single-phase voltage type AC/DC converting circuit, which has internal equivalent impedance as seen from an AC terminal, for converting single-phase AC power from a single-phase AC source to DC power to output from a DC terminal according to pulse width modulation of gate signals generated based on a PWM command; a phase difference generating circuit, which has a phase delay single-phase AC generator for delaying a phase of a single-phase AC output voltage at the AC terminal and generating a delay single-phase alternating current, for generating a phase difference voltage corresponding to phase difference between the single-phase AC output voltage at the AC terminal and an internal electromotive voltage of the single-phase voltage type AC/DC converting circuit based on the delay single-phase alternating current; an upper level voltage control circuit to which an upper command vector composed of a voltage amplitude command value and a frequency command value of the single-phase AC output voltage at the AC terminal is input for outputting a voltage command signal and a frequency command signal generated such that the amplitude and the frequency of the single-phase AC output voltage at the AC terminal approach the command values by the upper command vector based on the input upper command vector, the phase difference voltage from the phase difference generating circuit, and the single-phase AC output voltage at the AC terminal; a frequency control circuit for determining an electrical angle of the internal electromotive voltage of the single-phase voltage type AC/DC converting circuit to generate a generated electrical angle based on a reference frequency to define the frequency of the single-phase AC output voltage at the AC terminal, the frequency command signal from the upper level voltage control circuit, and an output signal from the phase difference generating circuit; and a lower level voltage control circuit for outputting a signal generated such that the amplitude, the frequency, and the phase of the single-phase AC output voltage approach a synthesized value of a reference voltage to define the amplitude of the single-phase AC output voltage at the AC terminal, the voltage command signal, and the generated electrical angle as the PWM command based on the single-phase AC output voltage at the AC terminal, the generated electrical angle of the frequency control circuit, and the voltage command signal from the upper level voltage control circuit, characterized in that the single-phase voltage type AC/DC converter being adapted in such a way that, when the AC terminal is connected to a distribution network of a single-phase alternating current and the DC terminal is connected to a DC device; the DC power between the single-phase voltage type AC/DC converter and the DC device is adjusted such that the frequency variation of a single-phase AC voltage of the distribution network decreases and magnitude of reactive power in the single-phase voltage type AC/DC converter is adjusted such that the voltage variation of the single-phase AC voltage of the distribution network decreases according to relationship between the upper command vector and the frequency and the voltage amplitude value of the single-phase AC voltage of the distribution network. a single-phase voltage type AC/DC converting circuit, which has internal equivalent impedance as seen from an AC terminal, for converting single-phase AC power from a single-phase AC source to DC power to output from a DC terminal according to pulse width modulation of gate signals generated based on a PWM command; a phase difference generating circuit, which has a phase delay single-phase AC generator for delaying a phase of a single-phase AC output voltage at the AC terminal and generating a delay single-phase alternating current, for generating a phase difference voltage corresponding to phase difference between the single-phase AC output voltage at the AC terminal and an internal electromotive voltage of the single-phase voltage type AC/DC converting circuit based on the delay single-phase alternating current; an upper level voltage control circuit to which an upper command vector composed of a voltage amplitude command value and a frequency command value of the single-phase AC output voltage at the AC terminal is input for outputting a voltage command signal and a frequency command signal generated such that the amplitude and the frequency of the single-phase AC output voltage at the AC terminal approach the command values by the upper command vector based on the input upper command vector, the phase difference voltage from the phase difference generating circuit, and the single-phase AC output voltage at the AC terminal;