Development Of Inverter Based On FPGA

FPGA (Field Programmable Gate Arrays) is a new type of IC (Integrated Circuit), integrating many control function module .It has advantages of full integration,good applicability,high performance-cost ratio and easy to be developed, so it has a variety of applications in many fields. Single-Phase Full-Bridge is a basic topology of inverters, studing on which can provide reference for research of Three-phase inverter. Therefore the analysis of single-phase full-bridge inverter has important significance.This paper is the development of SPWM controller based on FPGA,and the controller is applied in the experiment reseach of Single-Phase inverter.Main research contents included the software design of SPWM digital control system and the design of hardware circuit for inverter.The problems found in experiment are deeply analyzed,and corresponding solving schemes are put forward in this paper.On the side of hardware design,Firstly,the bipolar and unipolar SPWM technologies are analyzed respectively.The bipolar modulation suitable for high-frequency design is selected. Secondly, the influence of dead-time effect is analyzed in detail, forward compensation plan for waveform distortion is adopted with predicting the polar of bridge curent by judging phase angle between output voltage and current.Finally, real-time detection technology of voltage feedback is adopted to dynamically adjust PWM.On the side of software design,the design method of Top-down is adopted to divide function for control system.Many function units are completed such as DDS standard sine wave generator,SPWM producing unit,triangle wave generator unit,PWM producing unit with dead time compensation, judgment of current polarity module and feedback unit,etc.According to the glitch phenomenon during the simulation and the experimentation,the article analyses its generation mechanism and puts forward the common solving measures, improving the performance of the system.The simulation and experimentation research to the inverter are studied.The result shows that the controller designed have some features such as:have the advance compensate for dead time effect,have a rapid dynamic response rate,the frequency and amplitude of the output voltage were under function control.These features shows the feasibility and the validity of the scheme.