dq0 Transformation Interpretation
Significance of Dq0 axis transformation is that any rotating space vector generated by any no of phases balanced or unbalanced symmetrical or unsymmetrical can be decomposed into two orthogonal axis variables. Looking at the problem(transient&amp;steady state of system) from previous scenario is difficult to resolve or compare to two space decomposition as using Dq0 transformation. 

Origin of Dq0 transformation is symmetrical component which is given by fortesque . Later on Park used this as Dq0 transformation for electric machine problem. A three phase AC machine equations have six nonlinear time varying differential equations for stator and rotor voltages. Now they use ordinary ways to solve these equation for estimation of operational qualities is vary complex and rigorous.  

By using Dq0 transformation we could easily overcome this problem since Dq0 transformation makes time varying mutual fluxes(mutual inductance) independent to rotor position and differential equation becomes liner differential equation. 

Future the use of different Dq0 has good application in designing the controller for electric drives. Synchronous frame Dq0 makes all AC operating quantities as DC, and control of DC quality is easily obtained by PI or PID controller.