the servo drive closes a current lo

the servo drive closes a current loop and is modeled simply as a linear transfer function G(s). Of course the servo drive will have peak current limits, so this linear model is not entirely accurate, however it does provide a reasonable representation for our analysis. In their most basic form, servo drives receive a voltage command that represents a desired motor current. Motor shaft torque, T is related to motor current, I by the torque constant, Kt. Equation (1) shows this relationship.