Simulink Control Design™ - MathWorks

BLDC Motor Speed Control with Cascade PI controllers

This example illustrates one of several ways to tune a PID controller for an existing plant

in Simulink. Here, you use Closed-Loop PID Autotuner blocks to tune two PI controllers in

a cascade configuration. The Autotuner blocks perturbs the plant with closed-loop

experiment and performs PID tuning based on the plant frequency responses estimated

near the desired bandwidth. In contrast to the Open-Loop PID Autotuner block, here the

feedback loop remains closed and initial controller gains do not change during the

autotuning process.

BLDC Motor model

The model in this example uses a 3-phase BLDC motor coupled with a buck converter and

a 3-phase inverter power link. The buck converter is modelled with MOSFETs and the

inverter with IGBTs rather than ideal switches so that the device on-resistances and

characteristics are represented properly. Both the voltages of the DC-DC converter link

and the inverter can be controlled by changing the semiconductor gate triggers, which

control the speed of the motor.

mdl = 'scdbldcspeedcontrol';

open_system(mdl);

BLDC Motor Speed Control with Cascade PI controllers