PWM rectifier

About: PWM rectifier is a research topic. Over the lifetime, 2254 publications have been published within this topic receiving 25614 citations.

Circulating power test setup for a PWM rectifier motor drive

Abstract: Power converters burn-in test consumes large amount of energy, which increases the cost of testing, and certification, in medium and high power application. A simple test configuration to test a PWM rectifier induction motor drive, using a Doubly Fed Induction Machine (DFIM) to circulate power back to the grid for burn-in test is presented. The test configuration makes use of only one power electronic converter, which is the converter to be tested. The test method ensures soft synchronization of DFIM and Squirrel Cage Induction Machine (SCIM). A simple volt per hertz control of the drive is sufficient for conducting the test. To synchronize the DFIM with SCIM, the rotor terminal voltage of DFIM is measured and used as an indication of speed mismatch between DFIM and SCIM. The synchronization is done when the DFIM rotor voltage is at its minimum. Analysis of the DFIM characteristics confirms that such a test can be effectively performed with smooth start up and loading of the test setup. After synchronization is obtained, the speed command to SCIM is changed in order to load the setup in motoring or regenerative mode of operation. The experimental results are presented that validates the proposed test method.

Comparison of two control strategy for three-phase voltage source PWM rectifier

Abstract: In this paper, the mathematical model and work principle of the three-phase voltage source pulse width modulation (PWM) rectifier (VSR) are analyzed. Then, the control strategies without feed-forward and with feed-forward are compared, which based on the power factor, the total harmonic distortion (THD) and DC voltage stability. Voltage-Oriented Control (VOC) and direct current control method were adopted to obtain current tracking control. Meanwhile, a simplified algorithm was presented for space vector PWM (SVPWM), which simplifies the arithmetic process. Contrastive analysis of two control strategy results show that without feed-forward control strategy exits the faults of low power factor, high THD and so on, although its model is simple. While feed-forward control strategy has been proved more effective.

Electric field and potential determination for electrowinning cells with bipolar electrodes by finite difference models

Abstract: This paper is a contribution to the electric modeling of electrochemical cells. Specifically, cells for a new copper electrowinning process, which uses bipolar electrodes, are studied. Electrowinning is used together with solvent extraction and has gained great importance, due to its significant cost and environmental advantages, as compared to other copper reduction methods. Current electrowinning cells use unipolar electrodes connected electrically in parallel. Instead, bipolar electrodes, are connected in series. They are also called floating, because they are not wire-connected, but just immersed in the electrolyte. The main advantage of this technology is that, for the same copper production, a cell requires a much lower DC current, as compared with the unipolar case. This allows the cell to be supplied from a modular and compact PWM rectifier instead of a bulk high current thyristor rectifier, having a significant economic impact. In order to study the quality of the copper, finite difference algorithms in two dimensions are derived to obtain the distribution of the potential and the electric field inside the cell. Different geometrical configurations of cell and floating electrodes are analyzed. The proposed method is a useful tool for analysis and design of electrowinning cells, reducing the time-consuming laboratory implementations.

Modeling and Simulation of PWM Rectifier Based on Sliding-Mode Control

Abstract: To improve the poor starting performance of three-phase voltage source pulse width modulation (PWM) rectifier and suppressing its strong DC voltage fluctuation due to variation of load current, a sliding-mode variable structure based nonlinear voltage-loop control scheme is proposed to remedy the defect of conventional PI control based rectifier that is too sensitive to the variation of system parameters For this purpose, a new approach to design switching table in α-β coordinate system is put forward, by which not only good dynamic response characteristic of sliding-mode algorithm can be obtained, but also the switching frequency can be reduced effectively By use of the simulation model based on Matlab/Simulink, the simulative comparison of sliding-mode control scheme with PI control scheme is performed Comparison results show that the three-phase PWM rectifier controlled by sliding-mode variable structure is easy to design and implement, and it possesses good robustness and dynamic performance