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.

DC-link capacitor reduction of a controlled rectifier supplying N inverter-motor drive systems by compensating the load variations

Abstract: This paper deals with the compensations of the load variations in the control of DC-link voltage of the cascade of one rectifier-N inverter motor drive systems. The objective is to reduce the capacitance of the DC-link capacitors without affecting the stability of the DC-voltage control; so, the rectifier controllers should anticipate the load variation of the N inverter-motor drive systems. This is achieved by introducing compensating structures in the rectifier controllers; then, the DC-link voltage becomes almost insensitive to the load variations. This makes possible to design independently the controllers of the controlled rectifier from those of the inverter-motor assemblies. The presented simulation results validate the efficiency of the proposed methods.

Isolated Swiss-Forward three-phase rectifier for aircraft applications

Abstract: Recently an important increase of the electrical equipment in modern aircrafts is leading to an increase in the demand for electrical power. The usual electrical power distribution in aircraft applications is done via a three-phase 115Vac grid. A new trend of DC distribution is emerging employing a 270 Vdc grid. This yields the need for high-efficiency and high power-density AC-DC converters, connecting the two grids while providing galvanic isolation. Traditionally 12-pulse autotransformer passive rectifiers are used in aircraft applications. This converter is robust and highly reliable, however it is a non-controlled topology and it is relatively heavy because of the low frequency power transformer. Two-stage rectifier system approaches, employing three-phase PWM rectifiers or active filters and isolated DC-DC converters, are good alternatives to be applied in aircraft applications, to reduce the weight by using high frequency transformers and inductors. However, two-stage topologies process the energy twice leading to lower efficiency, power density. The reliability is also not very high due to a high semiconductor component count. This paper presents a new isolated single-stage PWM rectifier system, based on the recently presented non-isolated Swiss rectifier topology, called the Swiss-Forward rectifier. The principle of operation of this converter topology is presented together with detailed design guidelines and experimental validation on a 3.3kW 115Vac to 270Vdc prototype.

Circuit for supplying a dc load from an ac source through a rectifier

Abstract: An improvement A.C. a circuit for supplying a D.C. load from an A.C. source through an uncontrolled rectifier with a control element arranged between the output of the rectifier and D.C. load using a control unit synchronized with the A.D. source to keep the power factor at a predetermined value and the circuit including a capacitor associated with the DC control element and a by-pass diode bridged across the DC load in which, in order to suppress harmonics to the greatest degree possible, the DC load is bridged by two by-pass diodes connected in series in the same direction and the capacitor associated with the DC control element is connected between one input terminal and the center connection point of the two by-pass diodes. In a second variation, the same result is achieved with the capacitor and a first decoupling diode connected in series between the input terminals of the DC control element with one electrode of the capacitor connected with one input terminal of the DC control element and the other electrode of the capacitor through a second decoupling diode to an output terminal of the DC control element.

ESD protection circuit with low parasitic capacitance

Abstract: An ESD protection circuit includes a silicon controlled rectifier coupled between a circuit pad and ground for bypassing an ESD current from the circuit pad during an ESD event. An MOS transistor, having a source shared with the silicon controlled rectifier, is coupled between the pad and ground for reducing a trigger voltage of the silicon controlled rectifier during the ESD event. The silicon controlled rectifier has a first diode serially connected to a second diode in an opposite direction, between the pad and the shared source of the MOS transistor, for functioning as a bipolar transistor. In a layout view, a first area for placement of the first and second diodes is interposed between at least two separate sets of second areas for placement of the MOS transistor.