Switch, power conversion apparatus, and power supply system

A power supply system comprising:

• a control unit,
• a switch,
• a direct current source, and
• a power conversion unit, wherein the switch is electrically connected between the direct current source and the power conversion unit, and the control unit is configured to send a switch-off signal to the switch when a fault occurs on the direct current source or the power conversion unit;
• and the switch further comprises:
• a contact component, comprising a fixed part and a movable part, wherein the movable part is rotatably connected to the fixed part, the fixed part is provided with a fixed contact, the movable part is provided with a moving contact, the movable part has a central shaft, and the movable part is configured to rotate by using the central shaft as a center of rotation, to enable the moving contact and the fixed contact to be switched on or switched off;
• a knob configured to drive the moving contact and the fixed contact to be switched on or switched off;
• and
• a trip-free structure, disposed in a stacked manner between the knob and the contact component, wherein the trip-free structure comprises a trip unit and a transmission structure, the transmission structure comprises a connecting rod structure and a cradle, the connecting rod structure is connected between the cradle and the movable part, the cradle fits within the trip unit, the trip unit is configured to receive the switch-off signal to unlock the trip unit from the cradle, and the cradle is configured to drive the connecting rod structure to move, to separate the moving contact from the fixed contact, and switch off the switch.