Convertisseur d'Energie DC/DC

Objectifs

At the end of the first part of the training dedicated to the analysis of the SMPS topology analysis, the students will be able to master correctly all the equations and the main notions attached to the study of a DC/DC converter by showing that they are able to analyze the state-variable waveforms in steady-state to determine the performances of the system.

After the second part dedicated to the study of the voltage and current control loops, the students will be able to determine the type of controller required to regulate the state-variables of the system by showing that they are able to compute the pole and zero of the open-loop transfer function when it is necessary to insure the stability of a SMPS-type DC/DC converter.

Description

The course is divided into 3 distinct parts :

- 1) the study of the Buck converter topology (waveform analysis, CCM vs DCM, basic voltage control loop),

- 2) the study of the Boost converter topology (waveform analysis, CCM vs DCM, basic voltage control loop including a peak-current detection method)

- 3) the small-signal analysis of a Sample-Mode-Power-Supply: introduction to the state-variable analysis method, transfer function identification, design of the controller to insure the stability of the regulated system.

Practical work session using Cadence-Pspice simulator helps to illustrate the different concepts discussed in the course, namely: understand the shape of the several waveforms observed with the Buck converter, be able to design of a simple voltage control loop and measure the phase margin.

Compétences visées

- understand the principles of lossless energy transfer using SMPS topologies,

- know the different architectures used to provides an output voltage higher or lower than the input voltage : Buck converter, Boost converter, Buck-boost converter, SEPIC converter.

- be able to find the analytical expression of each characteristic of the converter using a waveform analysis method,

- understand the different method used to regulate the output voltage value for any type of load or any value of input voltage,

- be able to compute the poles and zeros of the controller in order to implement an unconditional stable control loop for the output voltage regulation.

- be able to understand the datasheet of an SMPS.

Bibliographie

D.M. Mitchell, “DC-DC Switching Regulator Analysis”, McGraw-Hill Companies.

Enseignants ENSEEIHT Génie Electrique, “Méthodes d’Étude des Convertisseurs Statiques”, Mentor Sciences.

Unitrode Application Notes U-97, U-93, U-111, U-140 and DN-62.

Pré-requis nécessaires

Knowledge of the basic concepts related to Kirchhoff laws and the MOSFET transistor (static and dynamic characteristics, Spice model level 1).