Table of Contents

This video consists of five parts (with review questions after each part):

Part 1: Introduction and Analysis of the Basic Building Block

• Identify the generic building-block in commonly-used, switch-mode power electronic converters. 

• Derive its average model in the continuous-conduction, as a function of the duty-ratio d. 

• Augment the same model by a dependent voltage-source and a dependent current source in the discontinuous-conduction mode.

• Use of PSpice to verify the validity of the average dynamic models and the enhancement of simulation speeds.

Part 2: Synthesis of dc and ac by PWM

• Simulation of single-switch converters (buck, boost and buck-boost) in switch-mode dc power supplies using the average model.

• Application of the building block for synthesis of dc and ac in switch-mode converters of dc-motor drives, single- and three-phase UPS, and three-phase ac-motor drives by pulse-width-modulation (PWM). 

• Computer simulations confirm the accuracy of the average-model based representations  in modeling large disturbances, which result in transition from continuous to discontinuous conduction, or vice versa.

Part 3: Feedback Controller Design in Switch-Mode dc Power Supplies

• Review of basic control theory: crossover frequency, phase margin, bandwidth, etc.

• Linearizing the PWM controller and the converter power stage in the continuous and the discontinuous-conduction modes.  Use of PSpice to produce the needed Bode plots of the transfer function with accuracy to high frequencies.

• A clear explanation of Type-1, Type-2, and Type-3 controllers, commonly used in switch-mode dc power supplies.

• A numerical example to design a voltage-mode controller for a Flyback converter operating in the continuous-conduction mode.  Comparison of simulations using the switching and the average representations.

•  A numerical example to design peak-current-mode controller for a Flyback converter operating in the continuous-conduction mode.  Comparison of simulations using the switching and the average representations under large disturbances to span both the continuous and the discontinuous conduction modes.

Part 4: Feedback Controller Design in Power-Factor-Correction (PFC) Circuits

• Discussion of the basic requirements.

• An easy-to-understand explanation of designing the inner average-current control loop.

• Considerations in designing the outer voltage loop.

• A numerical example of design in a 1-kW PFC to meet a 3% THD limit.

• PSpice-based modeling under large disturbances.

Part 5: Cascaded Feedback Controller Design in Motor Drives

• Advantages of cascaded control with torque, speed and position loops.

•  Linear representation of the PWM controller, the inverter and the motor.

• Explanation of the proportional-integral (PI) controllers used in motor drives.

• A numerical example of designing a cascaded controller.

• PSpice-based simulations to control position.

• Effects of limiters and integrator windup (and how to avoid it).