Developing DC-DC Converter Control in Simulink

Model-Based Design of a DCDC Converter using Simulink, Simscape and Stateflow

This workflow reference covers the design, analysis, and software development for a Single Ended Primary Inductor Converter, commonly known as SEPIC, which is powered by a 12 Volt lithium-ion battery and is converting voltage to 18 Volt to power 36 LEDs divided in 6 module with each 6 LEDs in series. The developed software include a simplified BMS (battery management system) to watch over the battery status, supervisory logic to coordinate mode of operation and two closed-loop controllers (SEPIC voltage and LEDs current).

Prerequisites and related content:

This content has been presented in a webinar, you can take a look for further explanations:

https://ch.mathworks.com/videos/series/how-to-develop-dc-dc-converter-control-in-simulink.html

It is strongly reccomended to complete following free Onramps before taking a look at the material (in this order):

MATLAB Onramp

Simulink Onramp

Stateflow Onramp

Simscape Onramp

Circuit Simulation Onramp

Power Electronics Simulation Onramp

Control Design Onramp with Simulink

The onramps are interactive, self-paced tutorial (around 2 hours length). It would be really beneficial to attend following (paid) trainings relevant to this topic:

MATLAB Fundamentals

Simulink for System and Algorithm Modeling

Stateflow for Logic Driven System Modeling

Modeling Physical Systems with Simscape

Power Electronics Control Design with Simulink and Simscape

Simulink Model Management and Architecture

Simulation-Based Testing with Simulink

Project details:

This project has been deveoped around a Texas instrument LED kit (codename: TMDSDCDCLEDKIT). It uses a F28069 ControlCard.

This application is interesting because:

• The SEPIC is using medium to high switching frequency (100 kHz)
• LEDs are current controlled using 20 kHz switching.
• Filter design plays an important role in getting current and voltage signals as proper inputs to the controllers

Both controllers are PI controllers which were modeled, simulated tuned and verified within the Simulink platform. Because the converter was modeled appropriately, the PI parameters derived in simulation can be used directly on hardware with good results.

Workflow

This demo covers a typical power electronics development workflow, divided in 5 sections:

System Modeling: Model the converter and calculate the most efficient operating region

Thermal Analysis: Determine power losses and the thermal behavior of the converter

Control Design and Tuning: Design control algorithm based on time/frequency domain specification

Logic Design, Verification and Verification: Design supervisory logic and implement unit testing

Embedded Code Generation: Implement power electronic controls on an embedded platform

Past releases:

See "Version History" tab in this entry