Research On High Power PWM Rectifier With High Power Factor

Based on a project for the traditional rectifier technical renewal of a Hefeicopper company, an energy saving high-power PWM rectifier with high power factorwhich is applicable to low-voltage distribution network is studied in this paper.Serving as the AC/DC converter of high frequency switching power supply forelectrolytic plating, the PWM rectifier has greatly reduced the harmonic content ofgrid-side current and then improved its power factor, realizing the efficient utilizationof energy and saving the cost. This paper mainly consists of following parts:Firstly, the topology and working principles of traditional high power rectifierare analyzed, which mainly concern diode and thyristor rectifiers. The majorproblems of traditional rectifiers are summarized in this paper by analyzing thedistortion rate of grid-side current and power factor. After that, a novel topology ofrectifier with LCL filter is presented. The working principles of its main circuit aredescribed in details with its mathematical model established. Secendly, the controlstrategy of the high-power PWM rectifier is discussed in this paper. A compositecurrent deadbeat control method based on power feed-forward for the PWM rectifieris proposed, realizing the real-time tracking of load power. To eliminate the resonanceof LCL filter, a control method combining virtual impedance is proposedto sustainsystem stability. Moreover, a control strategy for PWM rectifier`s operation underunbalanced conditions is proposed. The correctness and validity of the proposedcontrol method are verified by simulations. The stability analysis of the proposedcontrol system is also carried out in this paper and the results have shown a desiredstability performance with the presence of the control strategy.Thirdly, a high-power energy saving PWM rectifier of160kW is designed in thispaper. The detailed design scheme of the hardware and control system is put forward.And key technologies of PWM rectifier in engineering practice are studied. Methodfor improving the utilization of DC voltage is proposed with power module’s coolingsystem as well. Finally, the actual application effects of the device are given. Theresults have demonstrated that the novel efficient energy saving PWM rectifier hasseveral advantages such as low distortion of input current, non-pollution, high powerfactor and high energy utilization rate, etc.Regarding problems such as large harmoniccurrent and low efficiency of traditional electrochemistry rectification rectifiers, thispaper studies the topology structure and control technology forelectrolytic plating rectifier of high power and power factor. In combination with engineering examples,this paper proposes the design methods of hardware and software in details. Theresearch contents of this paper can provide references for traditional rectifier supplytechnical renewal.