Zhong Nie

An On-Line UPS System With Power Factor Correction and Electric Isolation Using BIFRED Converter

This paper presents the design consideration and performance analysis of an on-line, low-cost, high performance, and single-phase uninterruptible power supply (UPS) system based on a boost integrated flyback rectifier/energy storage dc/dc (BIFRED) converter. The system consists of an isolated ac/dc BIFRED converter, a bidirectional dc/dc converter, and a dc/ac inverter. It provides input power factor correction, electric isolation of the input from the output, low battery voltage, and control simplicity. Unlike conventional UPS topologies, the electrical isolation is provided using a high frequency transformer that results in a smaller size and lower cost. Detailed circuit operation, analysis, as well as simulation and experiment results are presented. A novel digital control technique is also presented for UPS inverter control. This controller follows the reference current and voltage of the inverter with a delay of two and four sampling periods, respectively.

An on-line UPS system with power factor correction and electric isolation using BIFRED converter

This paper presents design consideration and performance analysis of an on-line, low-cost, high performance single-phase Uninterruptible Power Supply (UPS) system based on Boost Integrated Flyback Rectifier/Energy storage DC/DC (BIFRED) converter. The system consists of an isolated AC/DC BIFRED converter, a bi-directional DC/DC converter, and a DC/AC inverter. It has input power factor correction, electric isolation of the input from the output, and control simplicity. Detailed circuit operation, analysis, as well as simulation and experiment results are presented.

SEPIC and BIFRED converters for switch-mode power supplies: A comparative study

The increased importance of power quality problem has attracted the attention towards power factor corrector (PFC) circuits for different power conversion systems. In this paper, a comprehensive comparison between single-ended primary inductance converter (SEPIC) and boost integrated flyback rectifier/energy storage DC/DC (BIFRED) converter, which are the two emerging PFC circuits, based on analytical relations, and simulation results are presented. All possible operating modes of SEPIC and BIFRED converters are also investigated. The authors also present equations for all operating modes. Furthermore, critical parameters for different operating modes to achieve very high efficiencies are discussed.

Special Section on Sustainable Transportation Systems

The 11 papers in this special section focus on state-of-the-art research and development, as well as future trends in the modeling, design, control, and optimization of advanced power electronics, energy storage, motor drives, and power train systems for future sustainable transportation systems.

Buck-boost integrated forward converter

An integrated converter is a synthesized converter based on the overall system integration, which is simplified by the system objective and can implement the system functions similar to the discrete converters. An integrated converter consists of converter sets; each converter set has a special function defined by the designer. A family of DC/DC buck boost based integrated rectifier with two active switches can be derived by the integration concept. In this paper, buck boost + forward integrated converter is proposed and fully explained. Five different operating modes, formulation, waveforms, output/input voltage ratio characteristics, small-signal models, transfer function, simulation results, and experimental verification are presented in detail

Buck Integrated Forward Converter

An integrated converter is a synthesized converter based on the overall system integration, which is simplified by the system objective and can implement the system functions similar to the discrete converters. An integrated converter consists of converter sets; each converter set has a special function defined by the designer. A family of DC/DC buck based integrated rectifier with two active switches can be derived by the integration concept. In this paper, buck + forward integrated converter is proposed and fully explained. Five different operating modes, formulation, waveforms, output/input voltage ratio characteristics, small-signal models, transfer function, simulation results, and experimental verification are presented in detail

A dSPACE control implementation for the standard three-phase boost rectifier

In this paper, a simple control method based on the six-step SVM is proposed for standard three-phase boost rectifier. The principle is derived from the average model of the three-phase boost rectifier. Input logic circuit and output logic circuit are given by analyzing the six-step space vector modulation. dSPACE based control circuit verifies this method. Results of simulation and experimental verification are presented.