The invention relates to a generator-operated motor and operation of a device consisting of an active bridge rectifier. In a method for energizing the device, phase terminals of the motor are connected to DC voltage terminals, respectively, by connectable and disconnectable flow control valves. When the output voltage between the DC voltage terminals exceeds an upper threshold value, all first flow control valves are turned on, and only when the output voltage has fallen below the lower threshold thereafter at the time lower than a time point and in addition the phase current flowing through each DC voltage terminal having the corresponding first flow control valve is below a turn-off threshold, each of the first flow control valves is turned off. Whether each first flow control valve has been turned off at least once after the time lower than a time point is inspected after a predetermined inspection period from the time lower than the time point and, if not, a local current minimum value of the respective phase current is detected and the first flow control valve is also turned off at the time point determined based on the current minimum value.