Synchronous machine current reference generator

**Library:**Simscape / Electrical / Control / SM Control

The SM Current Reference Generator block implements a current reference
generator for synchronous machine (SM) current control in the rotor
*d*-*q* reference frame.

The SM Current Reference Generator block can obtain the current reference using one of these methods:

Zero

*d*-axis control (ZDAC).Lookup tables.

For the ZDAC method, the block sets:

The

*d*-axis current reference ${i}_{d}^{ref}$ to zero:${i}_{d}^{ref}=0,$

The field current reference ${i}_{f}^{ref}$ using the torque reference:

${i}_{f}^{ref}=\frac{\left|{T}_{ref}{i}_{f,max}\right|}{{T}_{max}},$

where

*i*is the maximum field current and_{f,max}*T*is the maximum torque._{max}The

*q*-axis current reference ${i}_{q}^{ref}$ using the torque equation:${i}_{q}^{ref}=\text{}\frac{{T}_{ref}}{{K}_{t}{i}_{f}^{ref}},$

where

*T*is the reference torque input and_{ref}*K*is the torque constant of the synchronous machine expressed by the simplified torque equation $$T={K}_{t}{i}_{f}{i}_{q}$$._{t}

For operation below the base speed of the synchronous machine, ZDAC is a suitable
method. Above base speed, a field weakening controller is required to adjust the
*d*-axis reference.

To pregenerate the current references for several operating points, define three lookup tables using the lookup tables approach:

${i}_{d}^{ref}=\text{f}\left({n}_{m},{T}_{ref},{v}_{dc}\right),$

${i}_{q}^{ref}=\text{g}\left({n}_{m},{T}_{ref},{v}_{dc}\right),$

and

${i}_{f}^{ref}=\text{h}\left({n}_{m},{T}_{ref},{v}_{dc}\right).$

[1] Girardin, A., and G. Friedrich. "Optimal control for a wound rotor synchronous
starter generator." *Industry Applications Conference, 2006, pp.
14-19.*

[2] Carpiuc, S., C. Lazar, and D. I. Patrascu. "Optimal Torque Control of the
Externally Excited Synchronous Machine." *Control Engineering and Applied
Informatics, 14(2), 2012, pp. 80-88.*