Abstract: The voltage conversion apparatus includes a voltage holding unit that holds a maximum voltage of an output voltage and a determination unit that determines whether or not the maximum voltage held by the voltage holding unit is within a predetermined voltage range; when starting control of opening/closing operation by an opening/closing device, a control unit makes the opening/closing device perform the opening/closing operation, based on a predetermined starting switching frequency and a predetermined starting duty; the determination unit detects a failure in a smoothing capacitor by determining that the held maximum voltage is out of the voltage range.