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 Simple, Passive 24-Pulse AC–DC Converter With Inherent Load Balancing

Abstract: A new converter topology for a three-phase multipulse rectifier circuit is described. This converter draws almost sinusoidal currents from the ac system with very low harmonic content and typically less than 3% total harmonic distortion. The topology uses only passive components and has a lower component count than other rectifier circuits with similar performance. Two six-pulse rectifier bridges are connected in series, fed by a series connection of transformers, to form a 12-pulse system. An additional low power harmonic injection circuit enhances the performance of the circuit to obtain low harmonic current pollution levels that are comparable with those achieved from a 24-pulse rectifier. The circuit operation is explained and experimental results are presented.

Sensing methods and systems for hall and/or mr sensors

Abstract: Magnetic sensing methods and systems are disclosed. A minimum magnetic signal output and a maximum magnetic signal output can be detected utilizing a sensor comprising a peak detector circuit associated with a filter averaging circuit and one or more magnetic elements (e.g., a Hall element and/or magnetoresistive bridge). An average magnetic signal output can then be determined utilizing the filter averaging circuit when a target begins to rotate in front of the sensor. A minimum magnetic signal output and a maximum magnetic signal output can be detected utilizing a sensor that includes a peak detector circuit associated with a filter averaging circuit and one or more magnetic elements (e.g., a Hall element and/or magnetoresistive bridge). An average magnetic signal output can then be determined utilizing the filter averaging circuit when a target begins to rotate in front of the sensor.

Truly temperature independent current conveyor precision rectifier

Abstract: A current conveyor based rectifier circuit with very low temperature sensitivity is presented. The use of a current mirror arrangement to bias the rectifying diodes provides higher temperature stability than previously reported designs. The output offset voltage is easily adjustable to the desired optimum level.

An Auxiliary-Supply-Assisted Harmonic Reduction Scheme for 12-Pulse Diode Rectifiers

Abstract: Diode rectifiers have been widely used for an ac-to-dc converter. A big problem is that they include large harmonic components in the input currents. A 12-pulse configuration is useful for reducing them, but it still includes the (12 mplusmnl)th (m: integer) harmonics in the input currents. In order to further reduce the input current harmonics a single-phase square wave auxiliary voltage supply is inserted in the middle dc bus. It reduces harmonics especially the 11th and 13th and the harmonic characteristic becomes almost equivalent to a 24-pulse rectifier. Theoretical analysis of the combined 12-pulse diode rectifier with the auxiliary supply is presented, and a control method of the auxiliary supply is proposed. The reduction in the input current harmonics is verified by simulation and experimental results. The auxiliary supply is also applied to a 12-pulse thyristor rectifier.

Direct power control of three-phase PWM rectifier using space vector modulation-simulation study

Abstract: This paper proposes a novel and simple direct power control of three-phase PWM rectifiers with constant switching frequency using space vector modulation (DPC-SVM). The active and reactive power is used as the pulse width modulated (PWM) control variables instead of the three-phase line currents usually used. Moreover, line voltage sensors are replaced by a virtual flux (VF) estimator. The theoretical principle of this method is discussed. The steady state and dynamic results of DPC-SVM that illustrate the operation and performance of the proposed system are presented. It is shown that DPC-SVM exhibits several features as: simple algorithm, good dynamic response, constant switching frequency and particularly provide sinusoidal line current when supply voltage is not ideal. Results have proven excellent performances and verify the validity of the proposed system.