A converter, comprising a power factor correction, PFC circuit, a surge protection circuit, and a switch circuit, wherein the PFC circuit is configured to: convert a first component of a first alternating current received by an alternating current terminal of the PFC circuit into a first direct current, and output the first direct current through a direct current terminal of the PFC circuit, wherein an absolute value of an instantaneous voltage value of the first component is less than or equal to a preset threshold; and convert a second direct current received by the direct current terminal of the PFC circuit into a second alternating current, and output the second alternating current through the alternating current terminal of the PFC circuit; an alternating current terminal of the surge protection circuit is connected to the alternating current terminal of the PFC circuit, a direct current terminal of the surge protection circuit is connected to a first terminal of the switch circuit, and the surge protection circuit is configured to: convert a second component of the first alternating current into a third direct current, and output the third direct current through the direct current terminal of the surge protection circuit, wherein an absolute value of an instantaneous voltage value of the second component is greater than the preset threshold; a second terminal of the switch circuit is connected to the direct current terminal of the PFC circuit, and the switch circuit is configured to be turned on when the alternating current terminal of the PFC circuit outputs the first direct current, and to be turned off when the alternating current terminal of the PFC circuit outputs the second alternating current; and a controller, wherein the controller is configured to: control the PFC circuit to convert the first component into the first direct current, and convert the second direct current into the second alternating current, and to control states of the switch circuit, and the states comprise turn-off and turn-on. the PFC circuit is configured to: convert a first component of a first alternating current received by an alternating current terminal of the PFC circuit into a first direct current, and output the first direct current through a direct current terminal of the PFC circuit, wherein an absolute value of an instantaneous voltage value of the first component is less than or equal to a preset threshold; and convert a second direct current received by the direct current terminal of the PFC circuit into a second alternating current, and output the second alternating current through the alternating current terminal of the PFC circuit; an alternating current terminal of the surge protection circuit is connected to the alternating current terminal of the PFC circuit, a direct current terminal of the surge protection circuit is connected to a first terminal of the switch circuit, and the surge protection circuit is configured to: convert a second component of the first alternating current into a third direct current, and output the third direct current through the direct current terminal of the surge protection circuit, wherein an absolute value of an instantaneous voltage value of the second component is greater than the preset threshold; a second terminal of the switch circuit is connected to the direct current terminal of the PFC circuit, and the switch circuit is configured to be turned on when the alternating current terminal of the PFC circuit outputs the first direct current, and to be turned off when the alternating current terminal of the PFC circuit outputs the second alternating current; and a controller, wherein the controller is configured to: control the PFC circuit to convert the first component into the first direct current, and convert the second direct current into the second alternating current, and to control states of the switch circuit, and the states comprise turn-off and turn-on.