PWM rectifier

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

A High-Power-Factor PWM Rectifier without Voltage Sensors

Abstract: Pulsewidth modulation (PWM) control techniques for rectifiers are widely used to improve the source current waveform and the input power factor. Recently, methods to reduce the number of detectors are studied to simplify system configuration of such rectifiers and their control. It is known that a voltage detector on the ac-side can be omitted though a voltage detector on the dc-side is needed for adjustment of the dc-output of a PWM rectifier.In this paper, a method for controlling a single-phase rectifier without any voltage sensors is proposed. The ac-side voltage can be estimated from the input-reactor voltage when the ac-side of the bridge is short-circuited; the reactor voltage is easily obtained by multiplication of the inductance of the reactor and the derivative of the source current measured. On the other hand, the dc-side voltage can be estimated by calculating the difference between the source voltage at the beginning of every switching period and the reactor voltage sampled and held in the previous bridge conduction mode.This paper describes the control scheme and its implementation, and performance characteristics of the rectifier. The usefulness of the rectifier is confirmed by experiment. The method is applicable to various types of PWM rectifiers.

Control of a DC generator based on a Hybrid Excitation Synchronous Machine connected to a PWM rectifier

Abstract: This paper deals with the control of an hybrid excitation synchronous generator which is used to supply an isolated grid for aircraft applications. This grid is supposed to be a 270 V DC bus. Thus, a rectifier is required between the machine and the DC bus. Two structures can be used: diode or PWM rectifier. Here, only the structure with a PWM rectifier is studied. With a such system, it is possible to use a vector control applied to the structure in order to obtain minimal copper losses in the machine. The controller is synthesized here using a methodology based on a graphical representation of the system and then it is validated by simulation

Novel estimator of distorted and unbalanced electromotive force of the grid for control system of PWM rectifier with active filtering

Abstract: Control of PWM rectifier with active filtering is realized by fast and precise shaping of its AC currents. In the paper the control system with predictive algorithms of both set currents calculation and currents control is proposed. These algorithms provide very high accuracy and dynamics of AC currents shaping which is limited only by parameters of the power circuits. In both algorithms calculations are based on precise information about present and future samples of in general distorted and unbalanced equivalent electromotive force (emf) of the grid. For this purpose the novel, grid voltages sensorless, precise estimator and predictor of grid emf is proposed. This robust algorithm is based on digital signal processing techniques and requires relatively low computational effort. In this paper the simulations and experimental results are presented which show the performance of proposed estimator and predictor of grid emf and its influence on operation of the control system of PWM rectifier with active filtering

Higher harmonics compensation in grid-connected PWM converters for renewable energy interface and active filtering

Abstract: The paper presents overview of high-order harmonics compensation methods applied for control of grid-connected converter. Two harmonic compensation methods are presented. One based on band-pass filers cooperating with Direct Power Control with Space Vector Modulation (DPC-SVM) is dedicated for renewable energy interface. Second method based on resonant controllers applied in Voltage Oriented Control (VOC) adds an active filtering function to PWM rectifier. Simulation and preliminary experimental results for these two methods are presented. Streszczenie. Artykul prezentuje wybrane metody kompensacji wyzszych harmonicznych. Pierwszą bazującą na filtrach cyfrowych przedstawiono w aplikacji, w bezpośrednim sterowaniu mocy z modulacją wektorową (DPC-SVM) przeksztaltnikiem sieciowym. Drugą bazującą na regulatorach rezonansowych przedstawiono w sterowaniu napieciowo zorientowanym (VOC) jako funkcje aktywnej filtracji sterowanego prostownika sieciowego. Na zakonczenie przedstawiono wstepne wyniki badan symulacyjnych i eksperymentalnych. (Kompensacja wyzszych harmonicznych w sieciowym przeksztaltniku PWM)

Common mode current reduction method

Abstract: PROBLEM TO BE SOLVED: To reduce a common mode current applied to a power converter comprising a PWM rectifier circuit and a PWM inverter circuit at a low cost. SOLUTION: Semiconductor devices Q 1 , Q 3 , and Q 5 of a PWM rectifier circuit and semiconductor devices Q 7 , Q 9 , and Q 11 of a PWM inverter circuit are simultaneously turned on (or off) or, semiconductor devices Q 2 , Q 4 , and Q 6 of the PWM rectifier circuit and semiconductor devices Q 8 , Q 10 , and Q 12 of the PWM inverter circuit are simultaneously turned off (or on) to reduce a change of a common mode voltage and hence reduce a common mode current. As a result, the dimensional reduction of a common mode filter and the dimensional reduction of a cooler of a common mode current suppressor can be realized, so that the cost can be reduced. COPYRIGHT: (C)2003,JPO