Precision rectifier

About: Precision rectifier is a research topic. Over the lifetime, 4952 publications have been published within this topic receiving 63668 citations. The topic is also known as: super diode.

A Novel Variable Hysteresis Band Current Control of Three-Phase Three-Level Unity PF Rectifier With Constant Switching Frequency

Abstract: A Simple and novel variable hysteresis band current control technique for three-phase three-level unity power factor (PF) rectifier is proposed in this paper. The hysteresis band is controlled as variations of the rectifier input voltage and output dc link voltage to achieve constant switching frequency at any operating conditions, i.e., at rated and below and above the rated conditions. The rectifier has the characteristic of easy implementation, and draws a nearly sinusoidal current at unity input PF. Theoretical and predicted results of its analysis are verified initially through digital simulation, and confirmed by using an experimental prototype

A constant output current three-phase diode bridge rectifier employing a novel "Electronic Smoothing Inductor"

Abstract: This paper presents an improvement of the well-known conventional three-phase diode bridge rectifier with dc output capacitor. The proposed circuit increases the power factor (PF) at the ac input and reduces the ripple current stress on the smoothing capacitor. The basic concept is the arrangement of an active voltage source between the output of the diode bridge and the smoothing capacitor which is controlled in a way that it emulates an ideal smoothing inductor. With this the input currents of the diode bridge which usually show high peak amplitudes are converted into a 120/spl deg/ rectangular shape which ideally results in a total PF of 0.955. The active voltage source mentioned before is realized by a low-voltage switch-mode converter stage of small power rating as compared to the output power of the rectifier. Starting with a brief discussion of basic three-phase rectifier techniques and of the drawbacks of three-phase diode bridge rectifiers with capacitive smoothing, the concept of the proposed active smoothing is described and the stationary operation is analyzed. Furthermore, control concepts as well as design considerations and analyses of the dynamic systems behavior are given. Finally, measurements taken from a laboratory model are presented.

A technique for reducing rectifier reverse-recovery-related losses in high-voltage, high-power boost converters

Abstract: A circuit technique that reduces the boost power converter losses caused by the reverse-recovery characteristics of the rectifier is described. The losses are reduced by inserting an inductor in the series path of the boost switch and the rectifier to control the di/dt rate of the rectifier during its turn-off. The energy from the inductor after the boost switch turn-off is returned to the input or delivered to the output via an active snubber. The same technique can be extended to any member of the PWM power converter family.

Fault Diagnosis of a ZVS DC–DC Converter Based on DC-Link Current Pulse Shapes

Abstract: The dc-dc converter is a critical component in a hybrid electric vehicle since it supplies power to an electronic control unit, as well as chassis electric components such as power windows, wipers, etc. In this paper, a low-cost diagnostic method for MOSFET faults in a zero- voltage-switching dc-dc converter is proposed. The proposed method utilizes the dc-link current patterns as the signatures of faults of MOSFETs. A presignal processing circuit consists of a peak detector and an integrator circuit. The ratio of peak-to-integral values, which is similar to the crest factor, is useful for diagnosis.

Modular structure of an apparatus for regulating the harmonics of current drawn from power lines by an electronic load

Abstract: Modular apparatus for regulating the harmonics of current drawn from power lines by electric equipment, comprising a first rectifier circuit module, consisting of an array of rectifying diodes; a second Switch and Controller Assembly (SCA) module, which comprises a power switch and controller and their interconnections; an input inductor for filtering the current drawn from the rectifier module; and an output capacitor, for filtering the output voltage ripple at the load. The inlet of the rectifier is connected to the power line and an outlet of the rectifier module is connected to the SCA. The inlet of said SCA is connected to the rectifier, via an inductor and the outlet of said SCA is connected to the output capacitor. The inlet of the inductor is connected to the rectifier, the outlet of the inductor is connected to the inlet of said SCA, and the capacitor is connected in parallel with the load.