Many AC and DC drives are characterized to have parameters variation, sometimes significant, while operating. This results to the decrease of the control property and accuracy and impacts the technological process negatively. Thus, the problem of electric drives control system analysis aiming to provide low sensitivity of static and dynamic characteristics to parametrical fluctuations is very urgent. The typical current and speed control systems under variation of control object’s parameters are considered in the paper. The analysis of major disturbing factors in the electric drives is carried out. The interval models of control objects and elements of interval mathematics are used to study the robust properties of control systems. The integrated interval models of control objects allowing variation of major parameters in the speed and current control loops are obtained. Two types of current controller (with object lag compensation and without it) and three speed controller variants (P, PI, PID) with standard preferences are considered. Theoretical analysis of the robust properties of these systems is carried out using the coefficient evaluations of stability, property and accuracy. The current controller with control object lag compensation is shown to have greater sensitivity to the parameters variation. In the speed control loop the complication of the speed controller results to decrease of the sensitivity. The results of mathematical modeling confirming the conclusions drawn are given.