# PFC Single-Phase AC/DC Boost Converters: Bridge, Semi-Bridgeless, and Bridgeless Topologies
###### Abstract
BBC operation requires a closed-loop controller with a power filtering stage to simultaneously ensure EMI and \(THD_{i}\) reduction while keeping high PFC and regulating of DC voltage [27; 28; 29; 30; 31]. For these factors, a number of hardware changes for the BBC topology have been proposed by the scientific community which are explained in detail in this paper [4; 32; 33; 34; 35; 36; 37]. SBBC topologies allow for reducing conduction losses; basically, SBBC has less semiconductor devices in the path of the current from the source to the load compared to BBC topologies. However, this converter exhibits a significant amount of common mode noise in the input current, requiring additional components that increase the complexity of the circuit. The common mode problem is induced by the floating output ground, which is pulsating according to the switching frequency. In addition, this topology requires an additional inductor that increases the weight, size, and cost of the power converter. In this topology, EMI problems at the common coupling point can be reduced by adding diodes, capacitors, inductors, and also appropriate location of symmetrical switches for phase and neutral lines [38; 39; 40]. BLBC converters have an asymmetrical arrangement of their elements in the converter branches which mitigates reverse-recovery currents from diodes. It has no common mode interference problem because the output voltage is clamped to the input by diodes during each half-line cycle. Additionally, this topology has the potential capacity for bidirectional power conversion. Nevertheless, its inherent asymmetry increases the complexity of the controller and requires isolation in each driver of the branches [41; 42; 43]. For CBP converters, performance measures such as efficiency, number of components, PFC, \(THD_{i}\), maximum operating power, and other features are highly dependent on the circuit topology. In recent years, researchers have reported a large number of CBP topologies that have received increased attention from the scientific community [17; 27; 28; 35; 37]. Some bibliographic reviews that have gathered information on the BBC, SBBC, and BLBC have recently been published [16; 44]. However, these reviews neglect the analysis of interleaved converters and do not include any analysis regarding electromagnetic compatibility and power factor. In addition, review [16] was published in 2005, while review [44] was published in 2010; nonetheless, in the last decade, the scientific community has presented important advances in terms of new topologies, control systems, input filters, and power switches. This paper presents the CBP topologies and their modifications reported in the last fifteen years. In addition, according to the literature search, we found that CBP converters are called by different names by different authors; however, according to their topological structure, we categorized the converters into BBC, SBBC, and BLBC converters. Finally, this paper provides a comparative analysis that can be useful for researchers and developers to select the appropriate topology according to their application, showing their corresponding advantages and disadvantages and also giving recommendations. This paper is structured as follows: Sections 2-4 are respectively focused on the categorization of BBC, SBBC, and BLBC converters. Section 5 corresponds to the summary of the topologies included in the paper, and a comparative study is made in terms of: control type, voltage level, power level, number of semiconductors, and number of inductors and capacitors that compose each topology; in this section, recommendations are given to assist designers and developers in the topology selection process according to their particular requirements. Finally, Section 6 concludes and highlights the most relevant aspects of the paper.