| IGBT drive power occupies an important position in power electronic equipments.At present,the imported drive parts are expensive and the delivery time is long which can not meet the needs of customers.In addition,the product is designed by modularization,it can not be used flexibly.In order to solve these problems,we need to develop ourselves.The power supply is an important part of the IGBT drive.The flyback topology is usually the first choice of the power.It has the advantages of simple circuit,low cost,compact volume and so on.This paper focuses on the research of power supply and designs a IGBT drive board.First,this paper analyzes the common isolated and non-isolated switching power supply,studies the path of the current in different switching states of the power supply.After the study,this paper selects the voltage and current double loop flyback topology as the topology of the power supply.The electrical specifications of the switching power supply are obtained after we calculate the characteristics of IGBT.Then,according to the power specification,we design the transformer,choose the proper core and skeleton,introduce the winding method in detail.After finishing the transformer design,we complete the design of control circuit and main power circuit base on the UC2845 chip.We elaborate the circuit design principle and calculate the parameters of current,voltage and power of the devices,and confirm the selection of the devices.Then we simulate the transient and steady working process of the switching power supply by using software "Saber".The simulation results show that the circuit and the components meet the requirements.In the end,we design a prototype,we test the transient,steady,and short circuit waveforms of the main components.The waveform shows that the switching power supply works well,it can also protect itself well under short-circuit condition.The stress of the device is within the range of the device specification.The flyback closed loop switching power supply using separate device design effectively simplifies the circuit,reduces the cost,reduces the volume,and improves the usability of the product. |
