Simulation Study of Phase-Shifted Full-Bridge Converter Using MATLAB Software

The phase-shifted full-bridge converter is a widely adopted topology in power electronic systems, particularly advantageous in high-voltage high-power applications. MATLAB-based simulation studies enable engineers to validate control strategy effectiveness before hardware implementation, especially for complex scenarios like constant power control.

Simulation Model Construction When building a phase-shifted full-bridge circuit in MATLAB/Simulink environment, key components must be included: full-bridge inverter module (MOSFET/IGBT), high-frequency transformer, and output rectification/filter circuit. The core of phase-shift control involves adjusting the phase difference between bridge arms to modify output voltage, while constant power control requires additional closed-loop feedback, typically implemented using PI regulators to dynamically adjust phase-shift angles. In code implementation, this involves configuring Simulink's Power System Blockset components and designing appropriate control subsystems.

Constant Power Implementation Logic Constant power control operates by sampling output-side voltage/current signals, calculating real-time power, and comparing it with set values. The error signal processed through PI regulation generates phase-shift angle commands that ultimately drive the PWM generator. This process requires attention to algorithm robustness, such as incorporating low-pass filtering to suppress sampling noise. Implementation typically involves MATLAB function blocks or S-functions for power calculation and advanced control algorithms.

Simulation Key Points Soft-switching verification: Observe ZVS (Zero Voltage Switching) achievement in switching devices under phase-shift control - crucial for loss reduction; Dynamic response testing: Evaluate power regulation speed and overshoot during sudden load changes; Efficiency analysis: Assess efficiency curves under different loads combined with loss models. These analyses can be automated using MATLAB's data logging and post-processing capabilities through scripts that extract simulation results.

Through such simulations, control parameters (like PI coefficients, phase-shift ranges) can be optimized, providing theoretical foundation for actual hardware design. MATLAB's waveform analysis tools can visually display voltage-current phase relationships at key nodes, assisting debugging processes. The Simulation Data Inspector and Powergui tools are particularly useful for analyzing switching characteristics and controller performance.