Patent ID: 8076894

Claim:
A superconductive rotating electric machine drive control system comprising: a synchronous rotating electric machine that has a superconductive field winding and a copper armature winding or a superconductive armature winding; a power unit provided as a power supply unit that supplies power to the synchronous rotating electric machine or as a load unit that receives power from the synchronous rotating electric machine; an armature-side power converting device that converts electric power exchanged between the synchronous rotating electric machine and the power unit; a field power supply that supplies a field current to the synchronous rotating electric machine; a field-side power converting device that controls the current supplied from the field power supply to the superconductive field winding; an unified controller that coordinately controls a direct or alternating current flowing in the superconductive field winding and the copper armature winding or superconductive armature winding; and a refrigerating unit that cools down the superconductive field winding or both the superconductive field winding and the superconductive armature winding to a very low temperature, wherein, when the synchronous rotating electric machine is used as a synchronous motor, the unified controller performs a control operation so that a field current I f2 applied to the superconductive field winding of the synchronous rotating electric machine satisfies the following equation (11) in accordance with a variation of the electric power exchanged between the synchronous rotating electric machine and the power unit: I f2 =E 2 /k 4 n 2 ν=√{square root over (( V t cos θ− r 2 I ) 2 +( V t sin θ− x 2 I ) 2 )}{square root over (( V t cos θ− r 2 I ) 2 +( V t sin θ− x 2 I ) 2 )}/ k 4 n 2 ν (11) where I f2 represents the field current applied to the superconductive field winding, I represents a line current, E 2 represents an induced electromotive force of the synchronous rotating electric machine, V t represents a terminal voltage, k 4 represents a constant, n 2 represents a number of winding wires in the superconductive field winding, ν represents a rotation speed of the synchronous rotating electric machine, θ represents a power factor angle, r 2 represents resistance of the synchronous rotating electric machine, and χ 2 represent reactance of the synchronous rotating electric machine.