Working Machine

摘要

To provide a hybrid wheel loader capable of reliably detecting a short-circuited state of a synchronous generator driven by a drive source. The present invention is provided with an MG 4 being a synchronous generator driven as an electric generator by an engine and operated as a motor by the electric power supplied from an electrical storage device 9, an MG inverter 5 having a motor current sensor 5d for detecting motor current flowing through the MG 4 and semiconductor switches 5a, 5b, and an HCU 10 for detecting a short-circuited state of the MG 4, wherein the HCU 10 determines that the MG 4 is in a short-circuited state when the semiconductor switches 5a, 5b of the MG inverter 5 are in an OFF state at gates and when the motor current detected by the motor current sensor 5d is equal to or greater than a specified threshold value.

主权项

1. A working machine comprising:
a drive source; a permanent-magnet synchronous generator driven by the drive source; a drive unit driven by electric power generated by the synchronous generator; an inverter having a current detection unit for detecting electric current flowing through the synchronous generator and switching elements; and a control unit for detecting an electric abnormality in the synchronous generator; wherein when detecting the electric abnormality in the synchronous generator, the control unit turns off gates of the switching elements of the inverter and, where in this state an electric current equal to or greater than a predetermined value is continuously detected by the current detection unit for a predetermined period of time or more, judges that the inverter is in a short-circuited state.