Input Rectifier Bridge Research Articles

A New Bridgeless High Step-up Voltage Gain PFC Converter with Reduced Conduction Losses and Low Voltage Stress

Bridgeless power factor correction (PFC) converters have a reduced number of semiconductors in the current flowing path, contributing to low conduction losses. In this paper, a new bridgeless high step-up voltage gain PFC converter is proposed, analyzed and validated for high voltage applications. Compared to its conventional counterpart, the input rectifier bridge in the proposed bridgeless PFC converter is completely eliminated. As a result, its conduction losses are reduced. Also, the current flowing through the power switches in the proposed bridgeless PFC converter is only half of the current flowing through the rectifier diodes in its conventional counterpart, therefore, the conduction losses can be further improved. Moreover, in the proposed bridgeless PFC converter, not only the voltage stress of power switches is lower than the output voltage, but the voltage stress of the output diodes is lower than the conventional counterpart. In addition, this proposed bridgeless PFC converter features a simple circuit structure and high PFC performance. Finally, the proposed bridgeless PFC converter is analyzed and designed in the discontinuous conduction mode (DCM). The simulation results are presented to verify the effectiveness of the proposed bridgeless PFC converter.

Bridgeless PFC-Modified SEPIC Rectifier With Extended Gain for Universal Input Voltage Applications

In this paper, a new single-phase ac–dc PFC bridgeless rectifier with multiplier stage to improve the efficiency at low input voltage and reduce the switch-voltage stress is introduced. The absence of an input rectifier bridge in the proposed rectifier and the presence of only two semiconductor switches in the current flowing path during each switching cycle result in less conduction losses and improved thermal management compared to the conventional full bridge topology. Lower switch voltage stress allows utilizing a MOSFET with lower $R_{\rm{DS-on}}$ . The proposed topology is designed to operate in discontinuous conduction mode (DCM) to achieve almost a unity power factor and low total harmonic distortion (THD) of the input current. The DCM operation gives additional advantages such as zero-current turn-on in the power switches and simple control circuitry. The proposed topology is compared with modified full-bridge SEPIC rectifier in terms of efficiency, THD, and power factor. Detailed converter analysis, small signal model, and closed-loop analysis are presented. Experimental results for a 200 W/400 $V_{{\rm dc}}$ at universal line voltage range to evaluate the performance of the proposed bridgeless PFC rectifiers are detailed.

A High-Efficiency Single-Phase AC/DC Converter With Enabling Window Control and Active Input Bridge

The conventional continuous conduction mode boost converter has been widely used for power factor correction (PFC) applications because of its high input power factor and simplicity, but it suffers from conduction loss in the input rectifier bridge and switching loss due to the high switching frequency. The efficiency decreases significantly under the low input voltage or the light-load work condition. In this paper, a novel enabling window control (EWC) method is introduced to reduce the switching loss, and an active input bridge is used to replace the traditional diode bridge for high efficiency. The proposed EWC method is easy to implement with existing PFC ICs, and only a few additional control components are needed. Moreover, electromagnetic interference noise and driving loss of the main switch can be reduced with the EWC method. Semiconductor devices with competitive price can be used to reach efficiency as high as SiC diode and Cool-MOSFETs. A self-driven circuit is also used for the active bridge. The principle and design of proposed method are presented and the validity of the proposed method is verified by experimental results obtained from a 500-W prototype.

Control of DC Drive by Bridgeless PFC Boost Topology

This paper deals with the simulation of Bridgeless PFC boost Converter fed DC drive. The Bridgeless circuit is analyzed, designed and simulated with motor load. Conventional boost PFC suffers from the high conduction loss in the input rectifier-bridge. Higher efficiency can be achieved by using the bridgeless boost topology. In this paper, a systematic review of bridgeless power factor correction (PFC) boost rectifiers, also called dual boost PFC rectifiers, is presented. The circuit has advantages like reduced conduction loss, reduced harmonics and improved power factor.

Synthesis of Input-Rectifierless AC/DC Converters

This paper discusses the basic construction procedure and topological possibilities of creating AC/DC converters out of simple DC/DC converters. It is shown that two separately controlled DC/DC converters are sufficient for producing a regulated DC output and shaping the input current, from an AC voltage source, without the need for input rectifiers. Some design constraints are discussed, emanating from the limitation of the conversion ratios that can be achieved by particular DC/DC converters. Selected topologies are verified experimentally. This kind of rectifierless converter find applications in airborne power supplies where zero-crossing distortions are significant because of the inevitable phase-lead effect of the input rectifier bridge.

Power factor preregulators based on combined buck-flyback topologies

The limitation imposed on the achievable power level by the IEC 1000-3-2 standard in buck-derived power factor preregulators, is overcome by using a combined buck-flyback power stage. Two different step-down converters are proposed in this paper, which incorporate an auxiliary flyback stage. The auxiliary stage uses the same switch of the main converter, plus an additional power switch commutated at the line frequency. As compared to a simple buck rectifier, with this solution the harmonic content of the absorbed line current, at a given power level, can be reduced, thanks to the resulting increased conduction angle of the input rectifier bridge. Experimental results based on a 1 kW prototype are reported to validate the theoretical analysis of the proposed topologies.