Power conversion apparatus

A power conversion apparatus which converts power from a three-phase AC power supply to DC power, the power conversion apparatus comprising:

• a three-phase rectification circuit which rectifies output voltage of the three-phase AC power supply;
• a step-up converter circuit which steps up output voltage of the three-phase rectification circuit;
• a smoothing device which smoothes output voltage of the step-up converter circuit;
• a voltage detection circuit which detects output voltage of the smoothing device;
• an AC current component detection circuit which detects an AC current component in which ripple current of output current of the three-phase rectification circuit is superimposed;
• a control circuit which has a calculation section and a pulse generation section for controlling the step-up converter;
• and
• a single feedback control loop formed by the voltage detection circuit, the calculation section, and the pulse generation section, wherein
• the calculation section calculates a value obtained by subtracting a detection signal of the AC current component detection circuit and a detection signal of the voltage detection circuit from an output voltage instruction for the step-up converter circuit as a deviation,
• the pulse generation section having a single PI control circuit generates a pulse signal for suppressing the deviation to zero,
• the control circuit outputs the pulse signal to the step-up converter, and
• the step-up converter circuit includes:
• a reactor which stores the output current of the three-phase rectification circuit;
• and a switching device which controls charge and discharge of the current stored in the reactor in accordance with the pulse width of the pulse signal outputted from the control circuit.