Research On Two-phase Orthogonal Inverter Power Supply

In high quality special steel processing and smelting industry, continuous casting electromagnetic stirring technology has been the most effective technical approach to improve the quality and production yield of continuous casting steel. Two-Phase Orthogonal Inverter Power Supply is the key part of continuous casting electromagnetic stirring system, and the current waveform quality and response speed and other performances directly affect the quality of continuous casting steel. It has great significance to improve the manufacturing level of military vessels, Bridges, buildings, luxury cars and etc. This paper mainly consists of the following aspects:Firstly, the topological structure and working principle of traditional two-phase orthogonal inverter power supply are analyzed. The pre-stage of traditional two-phase orthogonal inverter power supply is an uncontrolled rectifier circuit, and the post stage is a two-phase full-bridge inverter made up with two single-phase inverters. Against the high current distortion rate, low system power factor and high hardware cost of traditional two-phase orthogonal inverter power supply, the PWM rectification technology is applied to two-phase orthogonal inverter power supply, and a kind of two-phase orthogonal inverter power supply is studied, whose pre-stage circuit is three-phase voltage source PWM rectifier and post-stage circuit is two-phase inverter with three bridge arms. After that, the working principles of the pre-stage and post-stage circuit are expounded in detail, and the mathematical models are established.Secondly, the control strategy of two-phase orthogonal inverter power supply is studied in-depth. For the dc-side voltage fluctuation problem caused by the change of load running state, a kind of dc-side voltage control method of two-phase orthogonal inverter power supply is proposed. By the feedforward power, the stationary control of dc-side voltage is realized. In order to realize fast tracking and accurate control of output current, deadbeat current tracking control method of the post-stage two-phase orthogonal inverter is put forward. The correctness and validity of the proposed control strategy are verified by simulation.Thirdly, the main circuit parameters and the control system hardware and software of the two-phase orthogonal inverter power supply are designed, with the DSP chip TMS320F2812 working as the main controller. Then on this basis, a two-phase orthogonal inverter power supply device with 120 k VA system capacity is developed. The experimental results verify the validity of the research work done in this paper.In this paper, against the high current distortion rate, high hardware cost, and dc-side voltage stationary control problem of traditional two-phase orthogonal inverter power supply, the topology structure and control strategy of two-phase orthogonal inverter power supply is researched. Then the two-phase orthogonal inverter power supply device is developed, including the detailed hardware and software design method. The research contents in this paper can provide reference for the performance improvement and engineering application of two-phase orthogonal inverter power supply.