A field-winding rotating electrical machine comprising: a motor generator having a field winding; a field current detecting section configured to detect field current flowing in the field winding; a field current control section configured to control the field current; a field current limiting section including a field current limitation determining section configured to calculate a determination value based on the field current detected by the field current detecting section and determining whether or not the determination value has reached a predetermined determination threshold value, and a field current limitation instructing section configured to generate, when the field current limitation determining section determines that the determination value has reached the predetermined determination threshold value, a field current limiting instruction to the field current control section so as to limit the field current to be equal to or smaller than a predetermined permissible value during a predetermined field current limitation time (T lim); characterized by a field current limitation releasing section configured to output a field current limitation releasing instruction to the field current limiting section so as to release limitation of the field current during a predetermined field current limitation release time (T C), wherein the field current limiting section, when having received the field current limitation releasing instruction from the field current limitation releasing section, configured to release limitation of the field current during the predetermined field current limitation release time (T C), wherein the field current limitation releasing section is configured to change the predetermined field current limitation release time (T C) in accordance with a time that has elapsed since the field current limiting section has started limiting the field current. a motor generator having a field winding; a field current detecting section configured to detect field current flowing in the field winding; a field current control section configured to control the field current; a field current limiting section including a field current limitation determining section configured to calculate a determination value based on the field current detected by the field current detecting section and determining whether or not the determination value has reached a predetermined determination threshold value, and a field current limitation instructing section configured to generate, when the field current limitation determining section determines that the determination value has reached the predetermined determination threshold value, a field current limiting instruction to the field current control section so as to limit the field current to be equal to or smaller than a predetermined permissible value during a predetermined field current limitation time (T lim); characterized by a field current limitation releasing section configured to output a field current limitation releasing instruction to the field current limiting section so as to release limitation of the field current during a predetermined field current limitation release time (T C), wherein the field current limiting section, when having received the field current limitation releasing instruction from the field current limitation releasing section, configured to release limitation of the field current during the predetermined field current limitation release time (T C), wherein the field current limitation releasing section is configured to change the predetermined field current limitation release time (T C) in accordance with a time that has elapsed since the field current limiting section has started limiting the field current.