A rotary electric machine apparatus comprising: a first power source connection terminal to which a first DC power source is connected; a second power source connection terminal to which a second DC power source whose voltage is lower than the first DC power source is connected; a power source switching mechanism that switches between a DC power supplied to the first power source connection terminal and a DC power supplied to the second power source connection terminal, and outputs; a rotary electric machine body having plural-phase windings; a winding connection switching mechanism that switches interconnection of the plural-phase windings between a first winding connection state, and a second winding connection state in which an induced voltage constant of windings becomes lower than the first winding connection state; an inverter that is provided with switching devices, and converts a DC power outputted from the power source switching mechanism and an AC power supplied to the plural-phase windings; and a controller that switches the power source switching mechanism, switches the winding connection switching mechanism according to a switching state of the power source switching mechanism, and drives on/off the switching devices to control the rotary electric machine body based on the switching state of the power source switching mechanism and a switching state of the winding connection switching mechanism, wherein when switching the power source switching mechanism to the first power source connection terminal side connection, the controller switches the winding connection switching mechanism so that the plural-phase windings become the first winding connection state, when switching the power source switching mechanism to the second power source connection terminal side connection, the controller switches the winding connection switching mechanism so that the plural-phase windings become the second winding connection state, wherein the rotary electric machine body is provided with three-phase windings as the plural-phase windings, and wherein the winding connection switching mechanism is a switching mechanism which switches interconnection of the three-phase windings between Y connection as the first winding connection state, and Δ connection as the second winding connection state. a first power source connection terminal to which a first DC power source is connected; a second power source connection terminal to which a second DC power source whose voltage is lower than the first DC power source is connected; a power source switching mechanism that switches between a DC power supplied to the first power source connection terminal and a DC power supplied to the second power source connection terminal, and outputs; a rotary electric machine body having plural-phase windings; a winding connection switching mechanism that switches interconnection of the plural-phase windings between a first winding connection state, and a second winding connection state in which an induced voltage constant of windings becomes lower than the first winding connection state; an inverter that is provided with switching devices, and converts a DC power outputted from the power source switching mechanism and an AC power supplied to the plural-phase windings; and a controller that switches the power source switching mechanism, switches the winding connection switching mechanism according to a switching state of the power source switching mechanism, and drives on/off the switching devices to control the rotary electric machine body based on the switching state of the power source switching mechanism and a switching state of the winding connection switching mechanism, wherein when switching the power source switching mechanism to the first power source connection terminal side connection, the controller switches the winding connection switching mechanism so that the plural-phase windings become the first winding connection state, when switching the power source switching mechanism to the second power source connection terminal side connection, the controller switches the winding connection switching mechanism so that the plural-phase windings become the second winding connection state, wherein the rotary electric machine body is provided with three-phase windings as the plural-phase windings, and wherein the winding connection switching mechanism is a switching mechanism which switches interconnection of the three-phase windings between Y connection as the first winding connection state, and Δ connection as the second winding connection state.