Design a 3 kW Phase-Shifted Full-Bridge Converter with Active Clamp

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This example shows how to model, analyze, and validate a gallium nitride (GaN)–based 3 kW phase-shifted full-bridge (PSFB) power converter optimized for high power density. The design uses an active clamp to reduce voltage stress on secondary-side synchronous rectifier MOSFETs, enabling the use of lower voltage-rated devices with improved figure of merit. The primary stage uses GaN devices to maintain zero-voltage switching (ZVS) over a wide operating range, improving efficiency compared to silicon-based implementations. The converter operates at 100 kHz and demonstrates high-efficiency performance suitable for compact power conversion systems.

This example demonstrates a model-based design approach for PMP23126 phase-shifted full bridge application. The example supports both simulation and code generation modes.

The model-based design workflow supports offline development, tuning, and validation of control algorithms before hardware deployment. By separating control algorithm development from firmware implementation, the model enables rapid iteration and reuse across platforms. Simulation results help verify control behavior and system performance early in the design process, reducing integration risk when transitioning to hardware.

Note: The model in this example is tested and shipped by Texas Instruments®.

Prerequisites

We recommend completing the following tutorials:

Required Hardware

  • TI F280039C

Available Models

The example includes the following models. To download and execute the model, see PMP23126 - 3kW Phase-shifted Full Bridge With Active Clamp.

Open Loop Control [Lab 1]:

  • PMP23126_PSFB_OpenLoop.slx

  • PMP23126_host_model_OpenLoop.slx

Closed Loop Control [Lab 2]:

  • PMP23126_PSFB.slx

  • PMP23126_host_model.slx

PMP23126_PSFB_Config.m has configuration settings for the simulation model. The file is integrated with both OpenLoop and ClosedLoop projects through model configuration parameters.

Run the Example on Hardware

Follow these steps to deploy the controller, power the system, and observe converter behavior under varying input and load conditions.

  1. Connect Power Hardware - Connect the electronic load and configure it for constant current (CC) mode. For open-loop testing, use constant resistance (CR) mode. Connect the high-voltage (HV) supply and the 12 V bias supply to the power board.

  2. Deploy the Controller - Build the model and deploy the generated code to the controlCARD connected to the power hardware.

  3. Power the Control Board - Apply the 12 V bias supply to the board. Verify that the controller initializes correctly and observe the PWM waveforms.

  4. Apply Input Voltage and Load - Enable the HV supply and apply 200 V to the converter input. Connect the electronic load and set the output current to 1 A.

  5. Connect Host Model - Run the host model to establish communication with the controlCARD.

  6. Increase Reference Voltage Gradually - Increase the reference voltage in 1 V increments until it reaches 3 V. Afterward, increase the input voltage to 385 V.

  7. Set Nominal Output Voltage - Once the input voltage reaches 385 V, set the reference voltage to 12 V and monitor the output response.

  8. Increase Load Current - Increase the load current in steps and observe output voltage regulation and system stability.