Robust currents control in the electric drive

The control systems of modern electric drives are built with using the principle of subordinate control, therefore the quality and accuracy of control of all external loops largely depends on internal control loops. In the article a typical, which is widely used in practice, and robust current control systems, which is obtained based on of a general solution of the polynomial synthesis equation, are considered. Generalized point (nominal) and interval models of the control object in the current loop are given. The interval model takes into account the possible parameters variations of the control object. The concept of the relative parameters variation of the control object, which is take into account both changes in process parameters and external disturbances, is introduced. The transfer functions of closed control loops confirming reliability of the proposed control design are calculated. Examples of using of robust current controllers in different types of electric drives are described. It is shown that the proposed structure of the robust current controller allow to save the quality and accuracy of control under significant changing in the gain and the time constant of the control object and significantly improve the processing of disturbance actions on the object.