A current sensor unit, comprising: a rectification module, configured to convert an AC current to a pulsed DC current; a power source conversion module containing an energy storage element, connected to the rectification module and configured to store energy for the energy storage element on the basis of the pulsed DC current during operation in a charging mode and to generate a power supply current on the basis of a voltage of the energy storage element; a mode switching module, connected to the rectification module and configured to be bypassed by the power source conversion module during operation in the charging mode, and to bypass the power source conversion module during operation in an energy release mode; a current sensor module, connected to the rectification module, the power source conversion module and the mode switching module separately and configured to detect a pulsed DC current flowing back from the power source conversion module or a pulsed DC current flowing back from the mode switching module; a control module, configured to acquire electrical energy from the power supply current, determine that operation is in the charging mode or the energy release mode on the basis of the voltage of the energy storage element, and acquire a first detection value that is provided by the current sensor module and relates to a pulsed DC current; and a self-calibration module, configured to generate a predetermined current flowing through the current sensor module in a self-calibration process, the self-calibration module comprising: a first switch configured to cut off the pulsed DC current flowing via the self-calibration module; a diode, an anode of the diode being connected to the rectification module; a capacitor, a first end of the capacitor being connected to a cathode of the diode; a second switch, connected to a second end of the capacitor; a voltage control current source (VCCS), connected in parallel with the capacitor; and a third switch, arranged between the voltage control current source (VCCS) and the current sensor module; wherein: the current sensor module is further configured to detect the predetermined current; and the control module is further configured to calibrate the first detection value on the basis of a second detection value that is provided by the current sensor module and relates to the predetermined current. a rectification module, configured to convert an AC current to a pulsed DC current; a power source conversion module containing an energy storage element, connected to the rectification module and configured to store energy for the energy storage element on the basis of the pulsed DC current during operation in a charging mode and to generate a power supply current on the basis of a voltage of the energy storage element; a mode switching module, connected to the rectification module and configured to be bypassed by the power source conversion module during operation in the charging mode, and to bypass the power source conversion module during operation in an energy release mode; a current sensor module, connected to the rectification module, the power source conversion module and the mode switching module separately and configured to detect a pulsed DC current flowing back from the power source conversion module or a pulsed DC current flowing back from the mode switching module; a control module, configured to acquire electrical energy from the power supply current, determine that operation is in the charging mode or the energy release mode on the basis of the voltage of the energy storage element, and acquire a first detection value that is provided by the current sensor module and relates to a pulsed DC current; and a self-calibration module, configured to generate a predetermined current flowing through the current sensor module in a self-calibration process, the self-calibration module comprising: a first switch configured to cut off the pulsed DC current flowing via the self-calibration module; a diode, an anode of the diode being connected to the rectification module; a capacitor, a first end of the capacitor being connected to a cathode of the diode; a second switch, connected to a second end of the capacitor; a voltage control current source (VCCS), connected in parallel with the capacitor; and a third switch, arranged between the voltage control current source (VCCS) and the current sensor module; a first switch configured to cut off the pulsed DC current flowing via the self-calibration module; a diode, an anode of the diode being connected to the rectification module; a capacitor, a first end of the capacitor being connected to a cathode of the diode; a second switch, connected to a second end of the capacitor; a voltage control current source (VCCS), connected in parallel with the capacitor; and a third switch, arranged between the voltage control current source (VCCS) and the current sensor module; wherein: the current sensor module is further configured to detect the predetermined current; and the control module is further configured to calibrate the first detection value on the basis of a second detection value that is provided by the current sensor module and relates to the predetermined current. the current sensor module is further configured to detect the predetermined current; and the control module is further configured to calibrate the first detection value on the basis of a second detection value that is provided by the current sensor module and relates to the predetermined current.