Study On High-efficiency Three-phase VSR-ZVZCS Power Micro-arc Oxidation Power Supply

The micro-arc oxidation surface treatment technology is a comprehensive application technology for generating a ceramic oxide film directly on the non-ferrous metal surface,and can solve the disadvantages of non-ferrous metal corrosion,wear,and low hardness.Micro-arc oxidation technology is an interdisciplinary discipline that includes the fields of electrochemistry,materials science,and power electronics,and is an important research hotspot for surface treatment of materials.The micro-arc oxidation power supply is the core part of the micro-arc oxidation technology.Currently,most of the micro-arc oxidation power supply adopts uncontrolled rectification or fully-controlled thyristor rectification circuits and hard-switching circuits,resulting in a large amount of harmonic content and large switching losses.Has become a"bottleneck"restricting the popularization and application of micro-arc oxidation power equipment.The subject has studied the PWM rectifier technology and soft switching technology for this"bottleneck",and designed a micro-arc oxidation power supply prototype with a three-phase PWM rectifier and a phase-shifted full-bridge ZVZCS DC/DC converter as the main circuit topology.The main part of the micro-arc oxidation power supply in this project adopts a three-phase PWM rectifier circuit,a phase-shifting full-bridge ZVZCS DC/DC converter,and a full-bridge chopping wave inverter circuit,and the three-phase VSR AC side inductance and DC bus.The high-frequency transformer and blocking capacitor of the capacitor and the phase-shifted full-bridge ZVZCS circuit were designed.The IGBT of the SEMIKRON company was selected as the main circuit switch,the IGBT drive circuit was driven by the TX-DA102D driver,and the communication circuit was the human-machine interface ET100.Data exchange and display with DSP via RS485 interface.The software part takes the digital processor TMS320F28335 as the core,and compiles the main program,external ADC sampling program,digital phase locked loop subroutine,SVPWM subroutine,double closed-loop control subroutine,PWM control program and soft start program.An experimental platform for micro-arc oxidation power supply was set up.The harmonic content and efficiency of the three-phase uncontrolled rectification and three-phase PWM rectification were tested with three-phase AC voltage U_ac=220V,load R_L=20?,and output power P_out=2.4kW.It is concluded that the three-phase uncontrolled rectifier harmonic content is 20 times that of the three-phase PWM rectifier,and the efficiency is improved by about 10%;the phase shift is performed under an experimental environment where the input DC voltage U_dc=560V,switching frequency f_s=40kHz,and load R=50?.The full-bridge ZVZCS circuit and hard-switching circuit perform switching loss testing and efficiency testing.When the output power reaches 4kW,ZVZCS can reduce the switching loss of about 100W,which is73.8%of the power consumption of the hard-switching switch;under all load conditions,ZVZCS The total power loss of the circuit is about 50%of the total power consumption of the hard-switching circuit.Through comparative experiments,it is verified that the micro-arc oxidation power developed by this subject has high efficiency and pure performance.In order to verify the micro-arc oxidation treatment effect of the micro-arc oxidation power source developed in this project,the micro-arc oxidation treatment was performed on the surface of the aluminum sheet.The appearance contrast of the aluminum sheet before and after processing and the power output waveform analysis were analyzed to meet the micro-arc oxidation technology requirements.Provide experimental basis and implementation scheme for the popularization and application of micro-arc oxidation power supply.