Design And Implementation Of Digital Electronic Transformer Based On Two Transistor Forward Topology

Under the background of continuous development of science and technology digital intelligent development is imperative and it has penetrated into every aspect of social life such as intelligent transportation smart grid smart medical smart home etc.and these intelligent digital development and application.The realization is based on digital control and is an inevitable trend for the development of intelligent digital power.Generally digital power supplies have high reliability and controllability and their application range will be expanded in various fields in the future.Therefore it is necessary to develop different digital power sources for different characteristics of power supply applications.This paper designs and studies a new type of 500W medium power digital power supply that is digital electronic transformer for the advantages and disadvantages of power frequency power supply and existing switching power supply in instrument power supply and this new electronic transformer structure can be used alone.Isolated DCDC module with voltage regulator module.n this paper,a digital transformer with wide load adaptability is designed based on the principle of dual-transistor forward topology of switching power supply.The digital transformer includes EMI filter,dual-transistor forward driver,high frequency transformer and digital function.Firstly,the advantages and disadvantages of medium power and switching power supply,as well as the current topology structure of switching power supply are deeply studied.The design of power supply and the digital functions of power supply,including EMI generation and suppression,drive in dual-transistor forward topology,design of high frequency transformer,generation and suppression of power ripple,digital protection function and digital interaction,are thoroughly studied.Functions and so on.Then STM32F301C8T6 is chosen as the main control chip to study how to realize the over-voltage and over-current protection by sampling the voltage and current of the original side in digital control,how to estimate the input and output power,how to realize the monitoring and shutdown operation of power supply by the host computer through PMbus protocol interface.Finally,by calculating the device selection of each part,the circuit diagram design and the welding and hardware debugging of the circuit board are completed,and the digital electronic transformer is assembled,and the unified debugging is combined with the software program and hardware.Final ly,the realization of digital electronic transformer with 45V/11.1A output is realized.The parameters of power output,voltage regulation rate,EMI and other indicators basically meet the design requirements.In a word,This project is mainly to reduce the volume and increase the power density compared to the medium power frequency power supply.Compared with the medium power switching power supply with the instrument power supply there is no need to sample on the secondary side and the protection and power detection are concentrated on the primary side digital part.And for the application scenario designed as an open-loop power supply which simplifies the circuit improves the reliability of the power supply and the transient response of the power supply;and proposes a new type of research on the drive circuit of the conventional two-switch forward topology drive circuit.