Hi
I want to ask somebody about the criterion for using one of the many algorithms that exists in the Sensorless Control of AC Motors. I mean, why some use Kalman type, others Observers and so on.

 

Before you worry about these issues, you must concern yourself with exactly what information you have as input to your algorithms: e.g. phase voltages, bus voltage, phase currents, bus current, etc.

Next, worry about the (non-linear) equations you are going to use to transform these inputs into useful state quantities, such as shaft angle, velocity, direct and quadrature current, etc.

At this point, if there are missing states, and/or your derived states are too noisy, you can look at implementing some kind of observer based on your model of the system. As a general rule, you want to start simple with a basic observer, and only go to a more complex observer such as a Kalman filter if you really need to.

Curt Wilson
Delta Tau Data Systems