Electrónica de Potência

Objectives

By the end of the course, students will be able to: - analyze a converter taking into account the main role of each device and also parasitic - design the schematic of the power section of a buck, boost and buck-boost - design the schematic of the power section of a flyback converter, push pull, bridge and half bridge converters - draw the waveform of node voltages and branch currents for continuous and discontinuous operation modes of previous converters - create the small signal model of a converter using the average model - simulate the linearized model of a converter using the DC transformer model - design control loops for switching converters using hysteretic, voltage and current mode control - evaluate stability of switched converters - understand the constraints of on-chip converters: available devices, parasitics, number of pins, voltage and current limit - design, block level, schematic of linear converter and charge-pump

Syllabus

1- Power Supply Circuit Fundamentals: Basic physics of power devices and circuits, converters classification, efficiency. 2 - Switching converters: Pulse width modulation and frequency modulation. DC-DC converters: buck, boost and buck-boost. 3- DC - DC converters with galvanic isolation: direct converter, flyback converter, push pull, bridge and half bridge converters. Analysis of the continuous and discontinuous conduction modes. 4- Modeling and Analysis of Switching Converter: Ideal DC model (DC current transformer model). Small signal models: average model. 5- Control Schemes of Switching Converters: Voltage-mode PWM control, hysteretic PWM control, Current-mode control. 6- On-Chip Voltage Converters: Voltage reference circuits, linear and switched step-down converters, step-up converters, charge-pumps, PSRR, line and load regulation

Prerequisites

Basic knowledge of electrical concepts: Ohm's and Kirchhoff's current and voltage laws (provided by the course of Circuit Analysis or equivalent). Also recommended (not mandatory): to be familiar with MOS transistor first level models (provided by the course of Electronic Circuits or equivalent)

Cross Competence Component

There are two students in each laboratory group. Interaction within the group and mutual help between groups is encouraged. When a group shows difficulties in a process, a different group that has already overcome the corresponding challenge is requested to provide assistance.It is estimated that soft skills account for 10% of the assessment.

Laboratorial Component

The LAB component is obtained in groups of two students. L1 - Analytical, manual waveform illustration and simulation of the possible operating modes of each switched converter (different circuit parameters are assigned to each group) - 3h L2 - Deriving the average model for a converter and simulate it using the DC-transformer model (different converter types and circuit parameters are assigned to each group). Add a control loop to the converter model and analyse stability - 6h L3 - Design and simulate a linear regulator analyzing stability and characterizing, PSRR, line and regulation - 6h L4 - Design and simulate a charge-pump characterizing efficiency, startup time and current driving capability - 6h Each part will be weighted according to the number of hours assigned: LAB=(3L1+6L2+6L3+6L4)/21 where L1 to L4 represent the grading of the parts with the corresponding name.

Programming And Computing Component

The simulator that will be used is LTSpice

Ethical Principles

All members of a group are responsible for the group’s work In any assessment, every student shall honestly disclose any help received and sources used. In an oral assessment, every student shall be able to present and answer questions about the entire assignment and solution.