Motor drive device, blower, compressor, and air conditioner

A motor drive device for driving a motor, the motor drive device comprising:

• a reactor having one end connected to an alternating current power supply;
• a converter circuit connected to another end of the reactor, the converter circuit converting a first voltage into a direct current voltage, the first voltage being an alternating current voltage output from the alternating current power supply;
• a capacitor for smoothing a second voltage, the second voltage being a voltage on a direct current side of the converter circuit;
• an inverter circuit for converting direct current power stored in the capacitor into alternating current power, and supplying the alternating current power to the motor;
• a first current detector for detecting a first current, the first current being an alternating current flowing between the alternating current power supply and the converter circuit;
• a second current detector detecting a second current, the second current being a direct current flowing between the converter circuit and the capacitor;
• a first overcurrent determination unit determining, on a basis of a detected value of the first current, whether the first current is an overcurrent or not;
• and
• a second overcurrent determination unit determining, on the basis of a detected value of the second current, whether the second current is an overcurrent or not, wherein
• a threshold for the first overcurrent determination unit to detect an overcurrent is lower than a threshold for the second overcurrent determination unit to detect an overcurrent,
• the converter circuit stops operating in a case in which a determination result of either the first overcurrent determination unit or the second overcurrent determination unit indicates an overcurrent, and
• the inverter circuit stops operating in the case in which the determination result of either the first overcurrent determination unit or the second overcurrent determination unit indicates an overcurrent.