linerization fails in presence of relay block

I am using a simulink model and has PMSM motor.model has speed and current control loop in model in order to give PWM signal i am using relay blok.for tuning the model i am using PID block for speed and current ,when ever i tune the block linerization is getting fail because of relay block .how can i tune moodel in presence of relay block

Answer 1

[Arkadiy Turevskiy]

When you launch PID Tuner, it tries to linearize your Simulink model. If you have strong discontinuities like relay exact linerization won't work.

In the case of relay, the best thing to do is probably tune the system without the relay, as in the continuous region relay is basically a gain of one. A quick thing to try is to comment through the relay block. Alternatively, you can specify a custom linearization behavior for the relay bloc, setting linearization to a gain of 1.