Solid-state switch-mode rectification converters have reached a matured level for improving power quality in terms of power-factor correction (PFC), reduced total harmonic distortion at input AC mains and precisely regulated DC output in buck, boost, buck-boost and multilevel modes with unidirectional and bidirectional power flow. This paper deals with a comprehensive review of improved power quality converters (IPQCs) configurations, control approaches, design features, selection of components, other related considerations, and their suitability and selection for specific applications. It is targeted to provide a wide spectrum on the status of IPQC technology to researchers, designers and application engineers working on switched-mode AC-DC converters. A classified list of more than 450 research publications on the state of art of IPQC is also given for a quick reference.

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A review of single-phase improved power quality AC-DC converters

This paper proposes two reduced switch count AC drive systems. One of the configurations was conceived for drives based on two-phase motors and the other for three-phase motors. The drive system provides both bidirectional power flow and power factor control. The pulsewidth modulation technique and the control strategy for providing unity power factor operation are discussed. Experimental results are presented.

AC motor drive systems with a reduced-switch-count converter

This paper investigates a reduced switch count dc-link ac-ac five-leg converter for three-phase power conversion. The converter provides both an input rectifier and an output inverter by sharing a leg in order to reduce the number of power switches. Scalar and vector pulsewidth modulation techniques are presented and the concepts of local and global apportioning factors are introduced. A control technique that aims at maximizing the utilization of the dc-link voltage is proposed. A hysteresis current controller that allows operating with one leg being shared by the load and grid sides is developed. In addition, several relevant characteristics of the converter are addressed, such as voltage capability, harmonic distortion, shared-leg and capacitor currents, and power rating. The features of such a converter are compared to those of the six-leg and four-leg converters. Selected experimental results are presented

Reduced Switch Count DC-Link AC&#8211;AC Five-Leg Converter

In this paper, two three-phase ac drive systems with reduced number of components, named configurations and , are investigated. Configuration uses multiple two-leg voltage source inverters in which all inverters share an extra-leg. Configuration also employs multiple two-leg inverters but in this case the inverters share the midpoint of a capacitor bank in the dc-link, instead. These configurations are compared to configuration that employs multiple three-leg inverters. The main characteristics of the machine drive systems are presented together with selected experimental results that demonstrate the feasibility of the proposed configurations.

Reduced Switch Count Multiple Three-Phase AC Machine Drive Systems

This paper investigates the use of a three-phase AC/AC power converter with a reduced number of devices as a motor drive system. The proposed power converter uses two four-switch three-phase power converter (FSTPC) topologies-one rectifier at the line side and one inverter at the machine side. Both power converters are controlled using the space vector PWM technique. The implementation of unity power factor in the front end rectifier is investigated. The unity power factor operation is obtained by using current vector controllers in the synchronous reference frame. The determination of the synchronous reference frame quantities is derived from the actual values of the line voltages. The induction machine is controlled by the use of the indirect field-oriented strategy. The operation of the power converter in the regenerative braking mode is evaluated from computer simulations. Finally, experimental results of control of an induction motor with the proposed power converter are presented.

AC/AC converter with four switch three phase structures

In this paper, a novel three-phase bidirectional interface is proposed by using only four active switches to simplify the hardware circuit and achieve unity power factor, sinusoidal input current, adjustable output voltage and bidirectional power flow capability. To ensure obtaining clean input current waveform, the current tracking mechanism is analyzed together with graphical aid and some critical design conditions are presented. Finally, a small-signal model is derived and, in addition to the feedback control, an instantaneous voltage detector is proposed for the added feedforward control to achieve almost zero output impedance and zero audio susceptibility. A prototype hardware circuit is constructed and some experimental results are presented for demonstration. >

Maoh-Chin Jiang

Papers

Control and implementation of a three-phase voltage-doubler reversible AC to DC converter