Design And Application Of PWM Converter Based On FPGA

The digital power has many advantages, such as flexible transform, accurate control, real-time supervising and better stability. In recent years, digital powers play an irreplaceable role in senior power management applications. As more and more international power design companies set foot in digital power field, it becomes the focus of power design. FPGA (Field Programmable Gate Arrays) is a new type of IC (Integrated Circuit), integrating many control function modules. With advantages of full integration, good applicability, high performance-cost ratio and being developed easily, it has a variety of applications in many fields.Based on a FPGA development board, a digital converter with voltage feedback PWM control mode is designed. It includes ADC controller, digital PID compensator and digital PWM generator. According to the adaptive sample rate and resolution ratio, a suitable ADC can be choosed. To design digital PID Compensator, a continue form compensator can be designed before it was transformed into a discrete one. According to the precision and resolution of the system, counter-compare method can be used in digital PWM generator.With the top-to-down approach, RTL-level design of this controller is carried out based on Quartusâ…¡. The design is easy to transplant and upgrade thanks to modularization. Each module is verified and the whole controller is simulated after the RTL level design. Finally, the designed file is downloaded to EP2C5Q208C8N chip at the FPGA kit to verify the system function.The test of the design has two steps. Firstly, the compensatory and stable characters of the system are tested in a system Simulink model. Secondly, buck circuit is tested by an oscillograph. The result indicates that the ripple ratio is 1.6% and the output voltage can recover to stable state rapidly when the load or the input voltage changes. The experimental results prove the feasibility of the proposed method.