  Practical applications of controllers often impose further requirements on
the implementation beyond the actual control performance, such as the ability
to switch between manual and automatic control or between different control
laws or controller parameter settings, known as bumpless transfer. Another
common requirement is to limit the control signal in magnitude and/or rate.
This article examines and extends several discrete-time variants of active
disturbance rejection control (ADRC), which is increasingly being applied
especially in the field of power electronics and drives, in this regard.
Detailed guidelines for practical ADRC implementations with these abilities are
presented, and all features are being demonstrated with the help of simulation
examples.
