A control device comprising: a detection unit configured to detect a first voltage between a positive electrode of an energy storage device and a first connection point of an energy conversion device, a second voltage between a negative electrode of the energy storage device and a second connection point of the energy conversion device, and a third voltage between the positive electrode and the negative electrode of the energy storage device, wherein: the energy storage device is connected to the energy conversion device via a first connection line in which a switch assembly is arranged; the first connection line comprising a first line for connecting the positive electrode of the energy storage device and the first connection point of the energy conversion device, and a second line for connecting the negative electrode of the energy storage device and the second connection point of the energy conversion device; the switch assembly comprising a first switch unit and a second switch unit which are respectively arranged on the first circuit and the second circuit; the detection unit comprising a fault detection circuit configured to be connected to the first connecting line, and the first connecting line and the fault detection circuit are configured to form a connection circuit between the energy storage device and the energy conversion device in case that the first connecting line is in a disconnected state; the fault detection circuit comprising a first sampling circuit, a second sampling circuit and a third sampling circuit, which are respectively configured to be connected with the first line and the second line, and respectively configured to detect a first voltage, a second voltage and a third voltage in case that the first switching unit and the second switching unit are in a disconnected state; the control device further comprising a processing unit configured to calculate a resistance value corresponding to the energy conversion device from the first voltage, the second voltage, and the third voltage detected by the fault detection circuit and resistance information corresponding to the fault detection circuit; and close the switch assembly to enable the first connection line to be in a closed state under the condition that the resistance value is greater than the resistance threshold value, so as to control the energy storage device to supply power to the electrical equipment through the energy conversion device. the energy storage device is connected to the energy conversion device via a first connection line in which a switch assembly is arranged; the first connection line comprising a first line for connecting the positive electrode of the energy storage device and the first connection point of the energy conversion device, and a second line for connecting the negative electrode of the energy storage device and the second connection point of the energy conversion device; the switch assembly comprising a first switch unit and a second switch unit which are respectively arranged on the first circuit and the second circuit; the detection unit comprising a fault detection circuit configured to be connected to the first connecting line, and the first connecting line and the fault detection circuit are configured to form a connection circuit between the energy storage device and the energy conversion device in case that the first connecting line is in a disconnected state; the fault detection circuit comprising a first sampling circuit, a second sampling circuit and a third sampling circuit, which are respectively configured to be connected with the first line and the second line, and respectively configured to detect a first voltage, a second voltage and a third voltage in case that the first switching unit and the second switching unit are in a disconnected state; the control device further comprising a processing unit configured to calculate a resistance value corresponding to the energy conversion device from the first voltage, the second voltage, and the third voltage detected by the fault detection circuit and resistance information corresponding to the fault detection circuit; and close the switch assembly to enable the first connection line to be in a closed state under the condition that the resistance value is greater than the resistance threshold value, so as to control the energy storage device to supply power to the electrical equipment through the energy conversion device.