Design Of 400Hz Digital Medium Frequency Inverter Power Supply Base On Virtual Synchronous Generator Algorithm

With the growth of people’s demand for green and efficient energy,high-performance inverter power supplies have become a research hotspot in the field of power electronics science and technology.With the increasing use of centralized high-power power supply methods in the application fields of radar,aircraft,ground maneuver support,etc.,the multi-module parallel technology of medium frequency inverter power supplies is a key issue that needs to be solved urgently.When inverter power supplies work in parallel,multiple and complex communication lines are required to connect,and the output voltage frequency,amplitude and other data volumes need to be monitored in real time,which will arrect and control the bandwidth in a traditional AC power system.In response to this issue,the virtual synchronous generator(VSG)control algorithm based on improved droop control designed is designed in this subject is used to solve the above problems.This method is based on droop control and increases virtual impedance to achieve the requirements of droop control characteristics.The VSG control algorithm enhances the system’s anti-interference ability against small disturbances,and no additional communication interface is required when the modules are operated in parallel.This subject uses the digital processor TMS320F28335 as the main controller,and the wave generation and protection functions are completed by FPGA ZYNQ7000.On this basis,the three-phase 400Hz intermediate frequency inverter power supply is studied.The main work of this subject is divided into three points:Firstly,construct the control method of the three-phase medium frequency inverter power supply and simulation research.The basic theoretical analysis and related parameter design methods of droop control and VSG control are carried out,and the external characteristics and existing problems of droop control and VSG control are analyzed respectively.By increasing the virtual impedance to solve the problem of the resistance of the line,and through the VSG control strategy,the inertia link is increased in disguised form to improve the anti-interference ability of the system.Through the splicing of these two control strategies,the inverter power system can be controlled more effectively.Secondly,design the main circuit of the medium frequency inverter power supply.According to the design index requirements,design its rectifier circuit,inverter circuit,high-frequency transformer,LC filter,various switching devices,and rectifier diode selection.Discrete mathematical modeling is carried out for the combined three-phase inverter circuit,and the three-phase static coordinate system(a,b,c)is transformed into a two-phase rotating coordinate system(d,q)according to the coordinate transformation,and the state equation is obtained.Combined with the control strategy,the operation of the medium frequency inverter power supply system is realized.Thirdly,design the control system.The control system is composed of TMS320F28335 as the core control chip and programmable FPGA ZYNQ7000 logic chip.The peripheral circuits include voltage,current,temperature sampling and conditioning circuits,overcurrent protection circuits and VFD screen display functions.The control software part is introduced in the form of a block diagram.Finally,Matlab simulation software was used to simulate the system,and a digital 400Hz medium frequency inverter power supply platform was built,and the system control waveform and output were verified.Prove that the experimental results meet the design requirements,in order to verify the feasibility of the proposed inverter power supply.