A three-phase PWM rectifier with active filtering function

Abstract

This paper presents a multi-function converter (MFC) as a viable solution to improve the power quality. The PWM rectifier (PWMR) operates as a rectifier to supply dc power to its linear or pulsating load and at the same time, operates as a shunt active power filter (APF) to improve the power-factor and to compensate harmonic and unbalanced currents drawn from non linear loads connected on the ac line. A simple control strategy which allows the converter to perform both functions (PWMR-APF) is presented. A Energetic study of the MFC and passive elements selection is analysed Simulation results made by MATLAB/SIMULINK under several loads configurations are presented to show the effectiveness and the reliability of the multi-function system.

Indirect Synchronization Phenomenon on Self-Oscillating Current Controllers

“…need to be better than 5% and accuracy ont its dephasing better than 5 degrees. These very constraining specifications impose the use of very fast control loop and especially self-oscillating current controllers [4], [3], [5]. But many experiments showed that for high frequencies of the input signal, deformations appeared in the frequential response of the system (see Fig.…”

“…It is characterized by optimal response and good accuracy. This is why it is often used for high performances applications such as active filtering [3] and test systems [4]. On the other hand, the basic hysteresis technique, given by Fig.…”

“…In lot of cases, these inner loops are sufficiently efficient to not disturb the global system operation and can be neglected or replaced by a fast and accuracy equivalent linear models. But in some applications, like active filtering [3] or test systems, it is necessary to well know the performances and the characteristics of these internal loops which are generally tested under hard conditions. An example is the emulation of power bodies such as electrical machines and batteries, for the help of the electric vehicles development [4].…”

Practical considerations in the PWM rectifier with active filter function

“…Several solutions have been developed, such as passive filters, shunt active power filters (S-APF) and PWM rectifiers (PWM-VSR), among others. An important trend consists in incorporating the functions of shunt active filter in PWM rectifiers (PWM-VSR-C), in order to compensate nonlinear loads [1]. At the present, there are works about the PWM-VSR-C that deals with several topics: the use of multilevel topologies [2], analog and fuzzy control schemes [3,4], and harmonic detectors [5].…”