A power conversion device, comprising: a DC-DC converter configured to reduce and output an input power; a current detector configured to detect a value of a current output by the DC-DC converter; a temperature detector configured to detect a temperature of the DC-DC converter; and a controller configured to set current values at which a control using droop characteristics is started in a multiple of stages in accordance with temperature values, and to carry out the control by switching the current value in accordance with the temperature detected by the temperature detector, wherein the controller is configured to read the output voltage, the output current, and the temperature detected by the temperature detector and to determine whether or not the temperature detected by the temperature detector exceeds a preset first threshold, and when the temperature detected by the temperature detector is equal to or greater than the preset first threshold the controller is configured to switch the current value at which the control is started to a second setting value smaller than a first setting value, and the controller is further configured to read the output voltage, the output current, and the temperature detected by the temperature detector during the control, to determine whether or not the temperature detected by the temperature detector exceeds a second threshold greater than the first threshold and when the temperature detected by the temperature detector is equal to or greater than the second threshold, the controller is configured to determine that there is a cooler abnormality and to switch the droop control start current from the second setting value to a third setting value smaller than the second setting value, and when the temperature detected by the temperature detector is less than the second threshold, the controller is configured to determine whether or not the temperature detected by the temperature detector is less than a third threshold that is smaller than the first threshold and the second threshold, wherein when the temperature detected by the temperature detector is less than the third threshold the controller is configured to return the droop control start current from the second setting value to the first setting value and to return to determining whether or not the temperature detected by the temperature detector exceeds the preset first threshold, and when the temperature detected by the temperature detector is equal to or greater than the third threshold, the controller is configured to return to determining whether the temperature detected by the temperature detector is equal to or greater than the second threshold. a DC-DC converter configured to reduce and output an input power; a current detector configured to detect a value of a current output by the DC-DC converter; a temperature detector configured to detect a temperature of the DC-DC converter; and a controller configured to set current values at which a control using droop characteristics is started in a multiple of stages in accordance with temperature values, and to carry out the control by switching the current value in accordance with the temperature detected by the temperature detector, wherein the controller is configured to read the output voltage, the output current, and the temperature detected by the temperature detector and to determine whether or not the temperature detected by the temperature detector exceeds a preset first threshold, and when the temperature detected by the temperature detector is equal to or greater than the preset first threshold the controller is configured to switch the current value at which the control is started to a second setting value smaller than a first setting value, and the controller is further configured to read the output voltage, the output current, and the temperature detected by the temperature detector during the control, to determine whether or not the temperature detected by the temperature detector exceeds a second threshold greater than the first threshold and when the temperature detected by the temperature detector is equal to or greater than the second threshold, the controller is configured to determine that there is a cooler abnormality and to switch the droop control start current from the second setting value to a third setting value smaller than the second setting value, and when the temperature detected by the temperature detector is less than the second threshold, the controller is configured to determine whether or not the temperature detected by the temperature detector is less than a third threshold that is smaller than the first threshold and the second threshold, wherein when the temperature detected by the temperature detector is less than the third threshold the controller is configured to return the droop control start current from the second setting value to the first setting value and to return to determining whether or not the temperature detected by the temperature detector exceeds the preset first threshold, and when the temperature detected by the temperature detector is equal to or greater than the third threshold, the controller is configured to return to determining whether the temperature detected by the temperature detector is equal to or greater than the second threshold.