Topology (electrical circuits)

About: Topology (electrical circuits) is a research topic. Over the lifetime, 33316 publications have been published within this topic receiving 397651 citations. The topic is also known as: topology.

Seventeen-Level Inverter Formed by Cascading Flying Capacitor and Floating Capacitor H-Bridges

Abstract: A multilevel inverter for generating 17 voltage levels using a three-level flying capacitor inverter and cascaded H-bridge modules with floating capacitors has been proposed. Various aspects of the proposed inverter like capacitor voltage balancing have been presented in the present paper. Experimental results are presented to study the performance of the proposed converter. The stability of the capacitor balancing algorithm has been verified both during transients and steady-state operation. All the capacitors in this circuit can be balanced instantaneously by using one of the pole voltage combinations. Another advantage of this topology is its ability to generate all the voltages from a single dc-link power supply which enables back-to-back operation of converter. Also, the proposed inverter can be operated at all load power factors and modulation indices. Additional advantage is, if one of the H-bridges fail, the inverter can still be operated at full load with reduced number of levels. This configuration has very low dv/dt and common-mode voltage variation.

A Zero-Voltage-Switching Bidirectional DC–DC Converter With State Analysis and Soft-Switching-Oriented Design Consideration

Abstract: This paper proposes a new soft-switching bidirectional DC/DC converter. The proposed converter achieves zero-voltage switching (ZVS) for the entire main switches and zero-current switching for the rectifier diodes in the large-load range. These features reduce switching loss, voltage and current stresses, and diode reverse-recovery effect. The simple electrical isolated topology with the soft-switching characteristic provides an attractive solution for a battery charge/discharge system in an electric vehicle, distributed power system, or uninterruptible power system. This paper describes the operation principle and the ZVS condition in detail. The mathematical model based on the state-space averaging method is also deduced to depict the performance characteristic. Then, design guidelines are presented to ensure the ZVS condition for all the switches. Finally, simulation and experimental results obtained from a 1-kW prototype verify the discussed theoretical analysis.

An Open-Switch Fault Detection Method and Tolerance Controls Based on SVM in a Grid-Connected T-Type Rectifier With Unity Power Factor

Abstract: Multilevel converter topologies are widely used in applications of wide-power range. The T-type topology, which is one of many three-level topologies, has an advantage in terms of efficiency compared to the neutral-point-clamped (NPC) type. In applications using the T-type topology, interest in reliability has been increased recently. Therefore, the open-switch fault detection method and tolerance control for T-type rectifiers, which are different from those of T-type inverters, are necessary to improve the reliability of applications. When the open-switch fault of switches connected to a neutral point occurs, an NPC-type rectifier cannot restore distorted input currents; however, a T-type rectifier is able to eliminate input current distortion completely. In this paper, an open-switch fault detection method is proposed and can find a position of the open-switch fault. Moreover, two tolerance controls based on space vector modulation are proposed and their characteristics are analyzed. The effectiveness and performance of the proposed open-switch fault detection method and two tolerance controls are verified by simulations and experiments.

Optimum behavior: Wireless power transmission system design through behavioral models and efficient synthesis techniques

Abstract: In this article, the different challenges and open issues regarding WPT systems have been presented considering both the transmitting and receiving ends. The challenges in the receiving side include the accurate modeling of the rectifying elements, the adequate selection of the rectifier topology, and the joint optimization of antenna and rectifier circuit. The challenges in the transmitting side are mainly in the improvement of the dc-to-RF conversion efficiency and in the selection of the optimum transmitted signal waveform. The final goal of most of these challenges is to take advantage of the nonlinear nature of the rectifying elements in order to maximize the RF-to-dc conversion efficiency in the receiving end of WPT systems.

Characterization of an active clamp flyback topology for power factor correction applications

Abstract: Flyback derived power convertor topologies have long been attractive because of their relative simplicity when compared with other topologies used in low-power applications. Incorporation of active clamp circuitry provides the additional benefit of recycling transformer leakage energy while minimizing switch voltage stress. This paper presents the analysis, design, and experimental results of 500 W single stage and 600 W interleaved active clamp flybacks used for power factor correction. Several practical issues, including the application of charge control, the use of mixed power devices, and a solution to the hold-up time problem are discussed and experimentally verified.