SPRACN0F October 2021 – March 2023 F29H850TU , F29H859TU-Q1 , TMS320F280021 , TMS320F280021-Q1 , TMS320F280023 , TMS320F280023-Q1 , TMS320F280023C , TMS320F280025 , TMS320F280025-Q1 , TMS320F280025C , TMS320F280025C-Q1 , TMS320F280033 , TMS320F280034 , TMS320F280034-Q1 , TMS320F280036-Q1 , TMS320F280036C-Q1 , TMS320F280037 , TMS320F280037-Q1 , TMS320F280037C , TMS320F280037C-Q1 , TMS320F280038-Q1 , TMS320F280038C-Q1 , TMS320F280039 , TMS320F280039-Q1 , TMS320F280039C , TMS320F280039C-Q1 , TMS320F280040-Q1 , TMS320F280040C-Q1 , TMS320F280041 , TMS320F280041-Q1 , TMS320F280041C , TMS320F280041C-Q1 , TMS320F280045 , TMS320F280048-Q1 , TMS320F280048C-Q1 , TMS320F280049 , TMS320F280049-Q1 , TMS320F280049C , TMS320F280049C-Q1 , TMS320F28374D , TMS320F28374S , TMS320F28375D , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376D , TMS320F28376S , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28378D , TMS320F28378S , TMS320F28379D , TMS320F28379D-Q1 , TMS320F28379S , TMS320F28384D , TMS320F28384S , TMS320F28386D , TMS320F28386S , TMS320F28388D , TMS320F28388S , TMS320F28P650DH , TMS320F28P650DK , TMS320F28P650SH , TMS320F28P650SK , TMS320F28P659DH-Q1 , TMS320F28P659DK-Q1 , TMS320F28P659SH-Q1
Conventional linear controllers such as the Proportional, Integral, Derivative (PID) are widely used with digital power applications, including motor control and motion control. The nonlinear PID (DCL Training Video - Non-linear Control) provided with the DCL extends the performance of its linear counterpart by shaping the loop error using a nonlinear law. A nonlinear shaping block is introduced in series with each of the three controller paths as shown below.
The shape and aggressiveness of nonlinear action are configurable via six additional controller parameters (two in each nonlinear block), which are typically tuned in an iterative fashion to optimize a transient response. Like other controllers in the DCL, the NLPID parameters can be updated safely using a shadow parameter set and an update function.
#T5843526-264 shows an example of the potential improvement in step response available from the use of nonlinear control action.
The NLPID executes with highest efficiency on devices equipped with the type 1 TMU (see GUID-5E5EBF43-A78B-40F9-B8A7-51DB8C80D65E.html#GUID-5E5EBF43-A78B-40F9-B8A7-51DB8C80D65E), such as the F280025 device. These devices have CPU instructions that allow the nonlinear controller to be executed in 117 cycles compared with around 3,300 cycles without such instructions. This cycle efficiency allows the nonlinear PID to be used in high frequency applications such as switching power supplies and current control loops.
The DCL is packaged in C2000Ware, which is available for free download by C2000 users. The library includes a PID controller tuning guide to help users get the most from the NLPID controller.