Introduction to Electric Drives

Description: Intro to Electric Drives explains how an electric drive efficiently converts electrical↔mechanical power, using a power-processing unit (PPU) plus controller/sensor feedback to deliver the right voltage/frequency to the machine. It surveys applications (wind energy, transportation, adjustable-speed drives for energy savings) and highlights the multi-disciplinary mix of machines, power electronics, control, DSP/real-time, sensors, mechanics, and grid interaction.

Description: This module shows how to translate a desired speed profile into required motor torque for both linear and rotating loads. It covers inertia, acceleration/speed/position relationships, power/energy, friction models, and torsional resonances that affect drive sizing and control.

Description: Introduction to mechanical–electrical analogies to model motor–load dynamics, including inertia, shaft stiffness, and damping. It explains coupling mechanisms (belts, rack-and-pinion/lead-screws, gears), four-quadrant operation, and why dynamic operation requires good controller design.

Description: Reviews AC circuit fundamentals needed for drives: sign conventions, RMS/phasor representation, and impedance-based (phasor-domain) analysis of RLC circuits. Defines instantaneous and complex power, apparent power, and power factor, with inductive/capacitive load behavior and leading/lagging PF.

Description: Reviews three-phase circuits used in power systems, including wye-connected sources/loads and how to interpret phase versus line-to-line quantities. Shows how balanced systems enable per-phase analysis, compares delta versus wye loads (including delta phase currents), and introduces wye–delta transformation for equivalent circuits.

Description: Explains what a Power Processing Unit (PPU) does in an electric drive and how it converts utility power into the form required by a motor. Breaks the PPU into rectifier, DC link, and switch-mode converter blocks, introducing PWM control and average modeling ideas.

Description: Surveys converter topologies used in DC-motor drives and three-phase AC-motor drives, focusing on switch-mode power conversion. Highlights how semiconductor devices and switching strategies shape output voltage/current for torque and speed control.

Description: Reviews magnetic-circuit fundamentals used in machines, including Ampere’s law, magnetomotive force, flux, and field/flux density concepts. Connects magnetic circuits to inductance and Faraday’s law, including magnetizing versus leakage flux.

Description: Introduces transformer operation as tightly coupled windings used for efficient power transfer and voltage conversion in power systems. Develops the equivalent-circuit view and discusses how parameters are estimated for practical analysis, with links to machine concepts.

Description: Builds the big-picture model of electromechanical energy conversion in drives, linking electrical and mechanical subsystems in motoring and generating modes. Explains how magnetic fields produce force/torque and induced EMF, and how losses impact efficiency.

Description: Introduces DC motor drives by classifying DC machines and explaining their physical structure and operating principle. Covers key effects like armature reaction and uses an equivalent-circuit viewpoint to relate voltage, current, torque, and speed behavior.

Description: Focuses on DC drive operating modes, including four-quadrant operation for motoring and braking across forward and reverse directions. Introduces flux-weakening for extended speed range and connects these modes to the power-processor (PPU) and electronic commutation concepts.

Description: Introduces feedback-control goals and definitions for motor drives, emphasizing cascaded control structures. Walks through a practical design flow using averaged PPU models and a DC-drive example, motivating PI control as a baseline regulator.

Description: Outlines a practical cascaded controller design procedure for motor drives, starting with the fastest inner torque loop. Then designs the speed loop assuming ideal torque control, and finally the position loop assuming ideal speed control.

Description: Introduces foundational AC machine concepts by describing sinusoidally distributed windings and the resulting air-gap field distribution. Develops three-phase winding ideas and motivates space-vector representations for compact analysis of sinusoidal quantities.

Description: Defines voltage and current space vectors and explains their physical interpretation for combining three-phase quantities into a single rotating vector. Develops space-vector components and shows how space vectors relate to familiar phasor-domain representations under balanced steady state.

Description: Introduces sinusoidal permanent-magnet AC (PMAC) drives with a block-diagram view linking PPU, controller, motor, and mechanical load. Explains PM synchronous machine structure and torque production, highlighting the analogy to DC and brushless DC drive concepts.

Description: Induced back-emf in PMAC stator windings from rotating rotor flux and from rotating stator current space vectors, then combines them into a net emf model. Builds a per-phase equivalent circuit and connects it to practical current-control approaches such as hysteresis control.

Description: Introduces load-commutated inverter (LCI) synchronous motor drives and the line-commutated converter interface used in high-power applications. Develops a per-phase synchronous-machine model and power-angle behavior, then discusses how excitation affects reactive power and power factor.

Description: Introduces induction motors under balanced sinusoidal steady-state operation and reviews common drive application categories. Describes the basic structure (three-phase stator and squirrel-cage rotor) and sets up the open-circuited rotor field picture used for later modeling.

Description: Explains induction motor torque production via induced rotor voltages and currents created by the rotating stator field and slip. Uses a transformer analogy to describe reflected rotor effects and shows how rotor currents and MMF interact with the air-gap flux.

Description: Discusses generator (regenerative braking) operation and shows how rotor leakage inductance and slip affect torque and power flow in induction machines. Develops a per-phase equivalent circuit and outlines standard tests (DC resistance, no-load, blocked-rotor) used to identify parameters.

Description: Covers line-fed induction-motor behavior at rated voltage and frequency, relating torque-speed characteristics to current draw, power factor, and efficiency versus load. Explains why direct-on-line starting produces high inrush current and motivates reduced-voltage soft-start approaches.

Description: Introduces efficient induction-motor speed control using variable frequency to keep slip (and rotor loss) small while avoiding saturation by reducing voltage with frequency. Develops constant-flux V/f ideas, includes stator-resistance voltage drop (voltage boost), and summarizes operating characteristics across speed.

Description: Reviews practical induction-drive considerations including start-up ramps, torque/power capability below and above rated speed, and generator-mode braking via negative slip. Introduces PWM PPU behavior and explains how switching harmonics affect motor losses and how harmonic-frequency models simplify analysis.