Boost Converter - Voltage Mode Control (Closed Loop)

Overview

This repository contains the C source code for a digital Voltage Mode Control (VMC) system implemented on a TI C2000 MCU (TMS320F28379D) for a DC-DC Boost Converter.

The control loop and switching both run synchronously at 10 kHz, regulating the output voltage to a reference target of 24V using a discrete PI controller.

System Specifications

• Controller Platform: TI F28379D (Delfino)
• Control Type: Voltage Mode Control (Single Loop)
• Switching Frequency: 10 kHz (ePWM2 - Up-Down Count Mode)
• Sampling Frequency: 10 kHz (ePWM1 - Up Count Mode)
• Target Output Voltage: 24V
• Feedback Scaling: 0-3.3V ADC input maps to 0-36V actual voltage.

Control Logic

The control system utilizes a discrete Proportional-Integral (PI) controller implemented in the Tustin (Bilinear) transformation.

Control Law

The error is calculated as: $$e[k] = V_{ref} - V_{act}$$

The duty cycle is updated using the incremental form: $$u[k] = u[k-1] + b_0 \cdot e[k] + b_1 \cdot e[k-1]$$

Where coefficients $b_0$ and $b_1$ are pre-calculated based on:

• $K_p = 100$
• $K_i = 100$
• $T_s = 100 \mu s$ (Sampling Time)

Hardware Peripherals Used

1. ADC A (Channel 2): Reads the output voltage feedback.
2. ePWM 1: Configured in Up-Count mode (TBPRD=2500) to act as the time-base, triggering the ADC and ISR at 10 kHz.
3. ePWM 2: Configured in Up-Down Count mode (TBPRD=5000) to generate the complementary PWM signals at 10 kHz.

File Structure

• main.c: Contains the main control loop, peripheral initialization, and the ISR.

Author

Rohan