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.

Modeling and nonlinear control of shunt active power filter in the synchronous reference frame

Abstract: This paper presents a modeling and a nonlinear control of three-phase voltage source shunt active filter. The modeling is based on the abc/dq transformation of the AC system variables. The currents injected by the active filter are controlled in the synchronous orthogonal dq frame using a decoupled nonlinear control strategy. The reference harmonic components are extracted from the sensed nonlinear load currents by applying the synchronous reference frame method, where a three-phase thyristor bridge rectifier with R-L load is taken as the nonlinear load. The voltage level of the DC side is regulated using a linearizing feedback control. The reference current needed to maintain a regulated DC voltage is added to the current loop reference. The transfer functions of the two loops are developed and synthesized to obtain the desired stability and dynamic response. Simulation results confirm the performances considered theoretically for the shunt active filter topology.

A Novel Single-Input Dual-Output Three-Level DC–DC Converter

Abstract: This paper proposes a novel nonisolated single-input dual-output three-level dc–dc converter (SIDO-TLC) appropriate for medium- and high-voltage applications. The SIDO-TLC is an integration of the three-level buck and boost converters, whose output voltages are regulated simultaneously. Reducing voltage stress across semiconductor devices, improving efficiency, and reducing inductors size are among the main merits of the new topology. Moreover, due to the considerably reduced volume of the step-down filter capacitor, a small film capacitor can be used instead, whose advantages are lower equivalent series resistance and a longer lifespan. A closed-loop control system has been designed based on a small-signal model derivation in order to regulate the output voltages along with the capacitors’ voltage balancing. In order to verify the theoretical and simulation results, a 300-W prototype was built and experimented. The results prove the aforementioned advantages of the SIDO-TLC, and the high effectiveness of the balancing control strategy. Furthermore, the converter shows very good stability, even under simultaneous step changes of the loads and input voltage.

A Battery Management System Using an Active Charge Equalization Technique Based on a DC/DC Converter Topology

Abstract: An active charge equalization technique based on a dc/dc converter topology is proposed in this paper The technique achieves cell balancing of batteries in a stack in terms of both voltage and charge as the pack is being charged/discharged and in idle periods to maximize the energy and reliability of stack operation A set of MOSFET switches controlled by a voltage monitoring circuit ensures that each battery module has the same output voltage by transferring charge from an individual battery module with the highest voltage to a weak module An overvoltage and overdischarge protection circuit is presented to reduce the degradation of battery life and to operate each battery within the voltage limits

Ambient light rejection for non-imaging contact sensors

Abstract: A sensor for capturing images of skin topology is provided having a platen, and a one or two-dimensional array of light sensing pixel elements for receiving light representative of skin topology when skin, such as finger(s), are present upon the platen. Such sensor being improved by structures, layers, or methods for reducing or blocking ambient light which would hinder the light sensing pixel elements from sensing the light representative of skin topology. The sensors are non-imaging contact sensors as they have platen to contact skin to be imaged, and do not require optics, such as lenses for focusing and/or magnification, to enable proper capture of light representative of skin topology on the sensor's light sensing pixel elements.

High efficiency drive system with 3-level T-type inverter

Abstract: In this paper an efficiency optimized variable speed drive is presented. It consists of the alternative 3-level T-type converter topology which is very efficient for low switching frequencies and a standard induction machine. The total system efficiency is optimized concerning the converter losses as well as fundamental and harmonic induction machine losses.