PWM rectifier

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

Be applied to electric automobile's compound energy memory

Abstract: The utility model discloses an electric automobile's compound energy memory, including detecting the control unit, PWM rectifier, direct current energy storage module and unsteady flow energy storage module. Unsteady flow energy storage module includes DCDC transform module and energy storage battery, and direct current energy storage module is super capacitor. Adopt establish ties respectively two -way DCDC converter and meet the system architecture of dc bus of energy storage battery and super capacitor, improve and fill discharge efficiency to furthest exerts the characteristic of super capacitor and battery, realizes the maximize of compound energy storage advantage. Super capacitor adopts the measure of flow equalizing with the battery. When the discharging or charge power and surpass it and discharge the most greatly or when charging the power limit value of an energy storage equipment, make it discharge or the power charge -discharge of charging according to the biggest, another kind of energy storage equipment decides according to its self the residual capacity condition and whether additionally compensates out -of -limit partial power.

Dynamic performance of grid connected AC/DC Voltage Source Converter under voltage dips transient conditions

Abstract: The intensive use of Voltage Source Converters (VSCs) in grid-connected applications requires control strategies that should be robust against voltage transients, such as voltage dips. The voltage dips are mainly caused by short-circuit faults; many of them last only a few tens or hundreds of milliseconds and they are unbalanced in most cases. The grid connected VSC from back to back structures is usually employed to control the DC-link voltage and the grid currents, keeping them within their allowed values. The dynamic behavior of grid connected AC/DC VSC under voltage dip transients is investigated in this paper. Three different control strategies are compared, emphasizing the advantages and disadvantages of each solution. Experimental results are presented for all three control strategies, using a 20 kVA AC/DC PWM rectifier prototype.

Soft-switch three-phase PWM rectifier with auxiliary free-wheel channel

Abstract: The invention discloses a soft-switch three-phase PWM (Pulse Width Modulation) rectifier with an auxiliary free-wheel channel. The soft-switch three-phase PWM rectifier comprises a three-phase bridge arm consisting of 6 total-control main switches respectively provided with antiparallel diodes and parallel capacitors, input filtering inductors connected between the middle points of each phase of bridge arm and an AC power grid, and an output capacitor connected to the output terminal of the three-phase bridge arm, wherein the total-control switches with both the antiparallel diodes and the parallel capacitors are connected or not connected to two ends of the three-phase bridge arm; an auxiliary switch with both antiparallel diodes and parallel capacitors is connected between a DC bus and the output capacitor of the three-phase bridge arm; and resonance branch circuits consisting of both resonance inductors and clamping capacitors are connected to two ends of the auxiliary switch in a bridging manner. The soft-switch three-phase PWM rectifier has a simple structure, and can inhibit reverse restoration of diodes and reduce electromagnetic interference. All switch devices of the rectifier achieve zero-voltage switch-on, have small loss and high circuit efficiency, facilitate improving the operating frequency and further improve the power density. The rectifier provided by the invention realizes output capacity and voltage control and achieves the power factor correction function of input current.

The Transient Current Control for Single Phase PWM Rectifiers

Abstract: Considering for the special demands of the single phase two-level PWM rectifier in railway drive application,the operation principle and work states are analyzed,the mathematic model of ideal switch is established,the principle of SPWM is presented,and transient current control is particularly analyzedTransient current control can reach unity power factor,stabilization of DC-link,low harmonic distortion of line current and so on,which is verified by computer simulation and experimental results

Secondary currents filtering by means of a properly sized winding in a multicoil traction transformer for high power applications to limit psophometric Currents

Abstract: In high power railway traction applications the modulation of traction converters, at low switching carriers, produces harmonic currents in the range of audio frequencies. To ensure correct operation modes of the signalling circuits, the interference magnitudes levels have to be reduced. Psophometric current (p.c.) gives an index of the interference level produced by traction equipments: it takes into account the harmonic content of the primary current waveform in the multiwinding transformer. To limit the p.c. in the feeding network, a method for filtering harmonic currents produced by the modulation of interlaced PWM rectifiers (V.S.R.) is described. A properly sized additional winding is considered on the multicoil transformer used to supply the traction equipment. In the paper the system is analysed by means of the mathematical model and some design guidelines are proposed.