in any control system if there are inner and outer loop, outer loop always produce a set point for inner loop. Because of a system time constant. So you must run outer loop to obtain a set point (references for Id and Iq) and run the inner (Current) loop to follow the set point. best results can be obtain if you run inner loop 10 times the outer loop
This control method is based on the vector control scheme, which is originally used for motor drive application.
The de-coupling components are used to against the coupling between inductive components, while you transform from natural reference frame to synchronous reference frame.
the outer control loop should have a slower speed and the inner one should has a faster speed, which is to avoid the interaction between 2 control loop
1) The dq control method is based on the vector control approach, which is generally used for motor drive application.
2)In real time applications voltage and currents are sensed in three phase applications. But to control the three phase components are difficult. Therefore for better controller design it is necessary convert the ABC component to two phase stationary component.
3) Generally in rotating frame the alpha and beta components are required by neglecting the zero sequence components. The zero sequence components are neglected because they are balanced components.
4) Many researchers regulates the active power by controlling the d-axis components and reactive power regulates by using q-axis components. It is quite easier and give faster response as compare to other control strategy
5)Generally, if the controller contains both inner and outer loop, outer control loop always generate a reference point for the inner control loop due to the system operation time is constant. Therefore the outer loop is used to obtain a reference point (references for Id and Iq) and the inner (Current) loop is used to follow the reference point.