Abstract: The control device for a rotary electrical machine which is connected between a DC power source and a rotary electrical machine and which controls driving of the rotary electrical machine by converting DC power from the DC power source into AC power, includes a power conversion circuit which is configured from a plurality of switching elements, a phase current detection unit which detects phase currents in the rotary electrical machine, a phase current ratio derivation unit which derives a ratio in which the phase currents detected by the phase current detection unit are equal to or greater than a reference value, or equal to or lower than the reference value, and an element fault determination unit which determines a fault status of each of the switching elements when the ratio derived by the phase current ratio derivation unit is equal to or greater than a previously established ratio threshold value.

Abstract: The control device for a rotary electrical machine which is connected between a DC power source and a rotary electrical machine and which controls driving of the rotary electrical machine by converting DC power from the DC power source into AC power, includes a power conversion circuit which is configured from a plurality of switching elements, a phase current detection unit which detects phase currents in the rotary electrical machine, a phase current ratio derivation unit which derives a ratio in which the phase currents detected by the phase current detection unit are equal to or greater than a reference value, or equal to or lower than the reference value, and an element fault determination unit which determines a fault status of each of the switching elements when the ratio derived by the phase current ratio derivation unit is equal to or greater than a previously established ratio threshold value.

Abstract: A discharge device includes a switch element connected in parallel to an electrical storage element; a constant current output unit which supplies a constant current to the switch element; and a control unit which gives an on or off instruction to the constant current output unit, wherein a configuration is such that the control unit controls the constant current output unit so as to cause energy with which is charged in the electrical storage element to be discharged while being consumed by the switch element, and within an optional time for which an energization current of the switch element reaches a limiting current of the switch element, turn off the switch element in a region in which the energization current is lower than the limiting current.

Abstract: A discharge device includes a switch element connected in parallel to an electrical storage element; a constant current output unit which supplies a constant current to the switch element; and a control unit which gives an on or off instruction to the constant current output unit, wherein a configuration is such that the control unit controls the constant current output unit so as to cause energy with which is charged in the electrical storage element to be discharged while being consumed by the switch element, and within an optional time for which an energization current of the switch element reaches a limiting current of the switch element, turn off the switch element in a region in which the energization current is lower than the limiting current.