direct axis

What Is Mean By XD And XQ? Xd- Direct-axis Synchronous Reactance the ratio of fundamental A.C. armature Voltage to A.C. armature current produced by the direct-axis flux. Xq- Quadrature-axis Synchronous Reactance the ratio of fundamental A.C. armature Voltage to A.C. armature current produced by the quadrature-axis flux. What is direct and quadrature axis reactance? In