Controlled electrical drives can be regarded as the most flexible and efficient source of controlled mechanical power. Understanding and developing the controlled electrical drive systems require a multi-disciplinary knowledge, starting from electrical machine theory, through electronic power converter technology to control system design techniques. This article gives a systematic overview of elements of a controlled electrical drive with emphasis on the control system design. The basic procedure of feedback and feedforward cascade control system design is presented for the separately-excited DC motor. It is then demonstrated that the basic principle of current/torque control can be applied to AC machines modeled in the rotational field coordinate frame, while the superimposed speed and position controller structure remains the same as with the DC motor. Finally, a notable attention is paid to analysis of transmission compliance, friction, and backlash effects, and their compensation by means of advanced control algorithms.