Modeling And Simulation Of The Influence Of SiC MOSFET On The Electrical Characteristics Of Inverter Arc Welding Power Source

Inverter arc welding power source is a device that provides electric energy for welding arc,and it is the core component of electric welding machine.The electrical characteristics of inverter arc welding power source have an important influence on the welding quality,and the power semiconductor device is the key device of inverter arc welding power source.In this paper,the influence of SiC MOSFET on the electrical characteristics of inverter arc welding power source is studied by numerical simulation,which is of great significance to the development and wide application of high quality inverter arc welding power source.With the help of MATLAB / Simulink software,the main circuit and control system model of SiC MOSFET inverter arc welding power source are established.Through the combination of theoretical calculation and system debugging,the values of resistance,inductance,capacitance and other electrical components in the main circuit of inverter arc welding power source are determined.The sampling program of voltage and current sampling module is compiled by using S-Function programming rules.Numerical simulation method is used to simulate the main circuit(type A)of single-phase bridge full controlled rectifier module and the main circuit(type b)of single-phase full wave controlled rectifier module in the inverter arc welding power source.Under the control of fuzzy control system,the change and state of constant load voltage and current at low frequency(25k Hz)and high frequency(100k Hz)are respectively simulated The simulation waveform of constant voltage external characteristics of inverter arc welding power source with A-type main circuit at25 k Hz frequency under dynamic load state.The results of numerical simulation show that when the frequency is 25 k Hz,the steady-state voltage of inverter arc welding power source with type a main circuit is 13.433v(about 2.42 times)higher than that of type B main circuit,and the steady-state current of inverter arc welding power source with type a main circuit is 667.4a(about 2.44 times)higher than that of type B main circuit.Therefore,when the frequency is 25 k Hz,the inverter arc welding power source with type a main circuit can output higher load voltage and current values;when the frequency is 100 k Hz,the steady-state voltage and current values of type B main circuit are higher than those of type a main circuit(the voltage is about1.36 times higher and the current is about 1.27 times higher).Therefore,when the frequency is 100 k Hz,compared with the A-type main circuit,the inverter arc welding power supply with B-type main circuit can obtain fast reaction speed,and also obtain high steady-state fixed value load voltage and current value;from the steady-state fixed value load voltage and current simulation waveform of the two main circuits at the frequency of 25 k Hz and 100 k Hz,it can be seen that the reaction speed of both is faster at 100 k Hz(Namely,the constant load voltage and current enter the steady state in a shorter time),but the fixed value load voltage and current value are lower under the steady state.The response speed of the two is relatively slow at 25 k Hz(Namely,the constant load voltage and will take longer to enter the steady state),but the fixed load voltage and current value are higher in the steady state.Therefore,the 100 k Hz inverter arc welding power source can obtain fast reaction speed and low constant load voltage and current value,while the 25 k Hz inverter arc welding power source can obtain slow reaction speed and high constant load voltage and current value.