A breaker apparatus, wherein the breaker apparatus is connected in series in a protected circuit, and is configured to disconnect an electrical connection when a fault occurs in the protected circuit; the breaker apparatus comprises: a first branch, comprising an overcurrent-automatic-disconnection unit and a first current limiting unit that are connected in series, wherein the overcurrent-automatic-disconnection unit is configured to be automatically disconnected when a current flowing through the overcurrent-automatic-disconnection unit exceeds a breaking current threshold, and the first current limiting unit is configured to limit a current on the first branch; a second branch, connected in parallel to the first branch and comprising a first controllable switch unit, wherein a control terminal of the first controllable switch unit is connected to a controller, and the first controllable switch unit is configured to be open or closed under control of the controller; and the controller, connected to the control terminal of the first controllable switch unit and the protected circuit, and configured to: when the protected circuit operates normally, control the first controllable switch unit to be closed, and when a fault occurs in the protected circuit, control the first controllable switch unit to be open, wherein the first controllable switch unit is any one or any series or parallel combination of the following: a relay and a contactor, characterized in that the controller is connected to the first branch, and the controller is further configured to: when the voltage value at the two ends of the first branch meets a preset condition, control the first controllable switch unit to be alternately open and closed, to clean the contacts of the first controllable switch unit. a first branch, comprising an overcurrent-automatic-disconnection unit and a first current limiting unit that are connected in series, wherein the overcurrent-automatic-disconnection unit is configured to be automatically disconnected when a current flowing through the overcurrent-automatic-disconnection unit exceeds a breaking current threshold, and the first current limiting unit is configured to limit a current on the first branch; a second branch, connected in parallel to the first branch and comprising a first controllable switch unit, wherein a control terminal of the first controllable switch unit is connected to a controller, and the first controllable switch unit is configured to be open or closed under control of the controller; and the controller, connected to the control terminal of the first controllable switch unit and the protected circuit, and configured to: when the protected circuit operates normally, control the first controllable switch unit to be closed, and when a fault occurs in the protected circuit, control the first controllable switch unit to be open, wherein the first controllable switch unit is any one or any series or parallel combination of the following: a relay and a contactor, characterized in that the controller is connected to the first branch, and the controller is further configured to: when the voltage value at the two ends of the first branch meets a preset condition, control the first controllable switch unit to be alternately open and closed, to clean the contacts of the first controllable switch unit.