Design And Research Of 1140V/200kW Mining Frequency Converter

In recent years,AC variable frequency speed regulation system has gradually replaced the DC drive system and has become the most promising speed regulation method by virtue of its excellent speed regulation performance and superior control effect.Compared with the induction motor,the permanent magnet synchronous motor can further improve the efficiency and control effect,and it is of great significance to develop the permanent magnet synchronous motor speed control system.On the other hand,due to the existence of explosive substances such as gas and dust underground in coal mines,universal frequency converter cannot be directly used in production.Therefore,the development of high-power flameproof frequency converter in coal mine is of great significance.This thesis takes the 1140V/200 k W mining frequency converter as the research object,and carries out systematic research work on the hardware selection,loss calculation,temperature field analysis and software design of the mine frequency converter.The main research contents are as follows:Firstly,a main power device selection scheme considering the influence of the power transformer is proposed for the two-quadrant AC-DC-AC inverter speed control system topology.The selection study of main power devices is carried out,and the selection basis of main power devices is given.On this basis,the analytical calculation of the losses of the main power device of the 1140V/200 k W mining frequency converter under different loads is carried out,and the calculation results of IGBT,Diode loss,junction temperature,and case temperature are given,which lay the foundation for the analysis of temperature field of frequency conversion speed regulation system.Secondly,the internal structure,thermal circuit model,heat transfer mode and heat transfer coefficient of the FF400R33KF2 C IGBT module were analyzed and a water-cooled radiator was designed;Based on Solidworks 3D modeling tool,the structure of the 1140V/200 k W mining frequency converter is designed,mainly including IGBT,rectifier diode,bus capacitor,Hall current sensor,which lays a foundation for the analysis of the temperature field of the variable frequency speed regulation system.Thirdly,based on ANSYS WORKBENCH finite element software,fluid-solid coupling simulation is performed for the main power part of 1140V/200 k W mining inverter.The specific mathematical model and control equations are given,based on which the temperature and fluid fields are modeled and simulated,the temperature distribution clouds of the main power device are given,and the factors affecting the heat dissipation performance of the heat sink are discussed.Finally,the software system of 1140V/200 k W mine frequency converter is designed and studied,and the mathematical model of permanent magnet synchronous motor in different coordinate systems,SVPWM modulation technology and parameter calculation of PI regulator are deduced.Based on PSIM software,the simulation research of 1140V/200 k W mine frequency converter is carried out,and the specific design process and simulation results are given.The simulation results verify the correctness of the proposed scheme.