| As the world's largest steel producer,China produced more than 1 billion tons of steel in 2020.With economic development and construction requirements,the country has higher requirements for steel quality.the technology of continuous casting electromagnetic stirring(CCES)is a method to boost efficiency.Meanwhile,the properties of cast slabs will be affected by it.The inverter is the central device of the CCES system.The reality effect of electromagnetic stirring(ES)usually influenced by the characteristic of output power supply.It is the core to improve the production efficiency and quality of continuous casting steel.The inverter of the traditional two-phase electromagnetic stirring(TPES)system has problems such as low current power factor on the mains side,high harmonic content,unstable DC side voltage,unbalanced output current between two phases and poor current control performance.In order to address these issues,this article looks at a new inverter of TPES system.The main research work is the following:First,the basic principles of TPES,inverter and pluse width modulation technology(PWM)is introduced,Of those widely used in the two-phase inverter's composition and principle is analyzed and comparison,Determined the inverter of TPES in this study using three-phase voltage PWM rectifier and the latest three-bridge inverter of Two-phases,and its working principle analysis and mathematical modeling is carried out.Secondly,A control structure is used Double closed circuit PI with,and a completely decoupling control method based on DP dual-phase stationary coordinate system introducing state feedback and input feedforward is proposed,which realizes the dualway complete decoupling control of the previous three-phase PWM.a control scheme Fuzzy PI is proposed,and fuzzy PI controller is designed for the two-phase inverter control circuit.,The fuzzy PI controller is used to control the modulation degree m to realize smooth and fast output current control and decoupling control of the effective value of current and frequency.Finally,Use MATLAB/Simulink to establish the variable frequency power inverter system studied in this document.and the overall circuit diagram of the system simulation and the specific structure circuit diagram of each control function module are given.A simulation verification experiment was designed to simulate the steady state performance and dynamic response performance of the rectifier circuit,inverter circuit,and the actual operating conditions of the electromagnetic stirrer.Finally,it was compared and simulated with the traditional ES system power inverter.The simulation results show that the design of the main circuit topology and control strategy in this paper is reasonable and effective,and provides a feasible new scheme for the design and realization of the variable frequency power supply of the electromagnetic stirring system. |
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