The Research On Large Current High Frequency Switching Power Supply Used For Metallurgy

Electrical energy plays an important role in the economic development and people’s lives.With the development of industry and the improvement of people’s living standard, Globalpower consumption growing every year. Meanwhile, as the proportion of nonlinear load is onthe increase, the power quality problems is becoming more and more serious. Among them,the rectifying power supply of the electrolysis, electroplating and other large powerconsumption hold large proportion in the industrial power. Therefore, the research onrectifying power supply with high efficiency and low harmonic content is of greatsignificance for improve power quality and enhance production efficiency.For decreasing the input current harmonic and enhancing the efficiency of conversion ofhigh power rectifier, based on the financial support of The Rectifier Source technicalimprovement Program of this paper hefei TongGuan GuoXuan Co., LTD., this paper statethree research contents such as the problems existing in the traditional rectifying powersupply, the harmonic treatment technology, a new high frequency PWM switch power supply.The emphasis and achievement of the paper mainly manifests in the following aspects:(1) This paper analyzes the operating principle and structure of two type traditionalrectifying power supply, which are based on rectifier diode and phase-control rectifier bridgerespectively. Then, the main problems existed in traditional rectifying power supply weresummarized respectively from two aspects such as harmonic current content on ac side andpower quality on dc side.(2) A deep research on low-voltage active filter harmonic current detection algorithmsand the double closed loop control strategy with outer voltage-loop and inner current-loop iscompleted in paper. The popular harmonic detection method based on Fourier transform andinstantaneous reactive power theory are investigated to compare them performance.According to the current tracking control problem, the operating principle of the PI controland deadbeat current control were analyzed respectively, and the deadbeat current controlbased control strategy for active power filters was put forward through the simulation resultscomparison. At the same time, take the engineering application of parallel hybrid active filterapplied in conventional rectifying power supply for example, a detailed explanation isdemonstrated in this paper, which is introduce the design method about control system oflow-voltage filter, main circuit and the design method of cooling system, etc.(3) This paper mainly focuses a novel high-frequency PWM swiching power supply withhigh efficient and low harmonic content. The structure, principle and mathematical model of two kinds of high-frequency PWM swiching power supply based on the voltage-sourceinverter and based on the current-source inverter are are described in this paper, respectively.The paper proposes the load power feedforward based deadbeat current control method for thevoltage-source inverter based high-frequency PWM rectifying power supply, and proposesthe load power feedforward based power factor angle closed-loop control method for thecurrent-source inverter based high-frequency PWM rectifying power supply. Finally, it isconcluded that the voltage-source inverter based high-frequency PWM switching powersupply economic has more superior performance index than current-source inverter basedhigh-frequency PWM rectifying power supply by comparing simulation effects.(4)Many sets of novel high-frequency PWM switching power supply parallel operatingin equal power flow is investigated in this paper. Through the analysis of several conventionaloperation technology in equal power flow and its existing problems, and puts forward a kindof power control method based on virtual internal impedance for many sets of high-frequencyswitching power supply parallel operating in paper. The simulation results verified theproposed power flow control technology is effective.This paper investigates the design and control technology of low voltage passive powerfilter（PPF） and active power filter（APF） to eliminate the harmonic current exist inconventional rectifying power supply, and describes in detail the design process of parallelactive power filter with advantages of PPF and APF based on engineering projects. This workcan be widely used for the technological improvement of traditional rectifying power supply.To research novel rectifying power supply with high efficiency and low harmonic content,this paper studies a kind of high-frequency PWM switching power supply, its workingprinciple, the control strategy and power control method in equal power flow for many sets ofhigh-frequency switching power supply parallel operating.