Converter and converter fault detection method

The invention provides a converter and a converter fault detection method. First, a controller outputs a drive current to a relay to drive a main contact and an auxiliary contact to switch to a targetstate. And the current state fed back by the auxiliary contact and the current value of the drivecurrent are obtained. A fault type is then determined according to the target state, the current stateand the current value. The fault type of the converter is determined by increasing the current value of the drivecurrent as a new detection factor and combining the target state and the current state. Influence on a detection result due to abnormity of the auxiliary contact or looseness of a feedback line between the auxiliary contact and the controller is eliminated, the error probability of contactor fault detection is reduced, the accuracy of contactor fault detection is improved, the probability of generator shutdown caused by error diagnosis is reduced, and the utilization rate of the wind generating set is guara