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.

Field test of the wavelength-saving quantum key distribution network

Abstract: We propose a wavelength-saving topology of quantum key distribution(QKD) network based on passive optical elements, and report the field test of this network on the commercial telecom optical fiber. In this network, 5 nodes are supported with 2 wavelengths, and every two nodes can share secure keys directly at the same time. All QKD links in the network operate at the frequency of 20 MHz. We also characterized the insertion loss and crosstalk effects on the point-to-point QKD system after introducing this QKD network.

An innovative technique for packaging power electronic building blocks using metal posts interconnected parallel plate structures

Abstract: Power electronics building blocks (PEBBs) are envisioned as integrated power modules consisting of power semiconductor devices, power integrated circuits, sensors, and protection circuits for a wide range of power electronics applications, such as inverters for motor drives and converters for power processing equipment. At the Center for Power Electronics Systems, we developed a topology for a basic building block-a two-switch two-diode half-bridge converter in totem-pole configuration with built-in gate-driver and protection circuitry, fiber-optic receiver/transmitter interface, and soft-switching capability. Based on the topology, a series of prototype modules, with 600 V, 3.3 kW rating, were fabricated using an innovative packaging technique developed for the program-metal posts interconnected parallel plate structure (MPIPPS). This new packaging technique uses direct attachment of bulk copper, not wire-bonding of fine aluminum wires, for interconnecting power devices. Electrical performance data of the packaged devices show that an air-cooled 15 kW inverter, operating from 400 V dc bus with 20 kHz switching frequency can be constructed by integrating three prototype modules, which is almost double what could be achieved with commercially packaged devices of the same rating.

A Distributed Fault-Tolerant Topology Control Algorithm for Heterogeneous Wireless Sensor Networks

Abstract: This paper introduces a distributed fault-tolerant topology control algorithm, called the Disjoint Path Vector (DPV), for heterogeneous wireless sensor networks composed of a large number of sensor nodes with limited energy and computing capability and several supernodes with unlimited energy resources. The DPV algorithm addresses the $k$ -degree Anycast Topology Control problem where the main objective is to assign each sensor’s transmission range such that each has at least $k$ -vertex-disjoint paths to supernodes and the total power consumption is minimum. The resulting topologies are tolerant to $k-1$ node failures in the worst case. We prove the correctness of our approach by showing that topologies generated by DPV are guaranteed to satisfy $k$ -vertex supernode connectivity. Our simulations show that the DPV algorithm achieves up to 4-fold reduction in total transmission power required in the network and 2-fold reduction in maximum transmission power required in a node compared to existing solutions.

Identification of topology errors in power system state estimation

Abstract: This paper deals with the processing of topology errors in power system state estimation. An algorithm is proposed for determining a correlation index between symptoms of anomalies in the estimation process and measurements related to the network-elements suspected of being misconfigured. A method based on such an algorithm enables one to recognize the occurrence of topology errors in the real-time modeling process and to identify the misconfigurations. The proposed method has been tested on three different power systems, including a realistic network which is part of the Southern Brazil interconnected system, for various types of topological errors (inclusion, exclusion and bus-split errors). >

Constant current light emitting diode (LED) driver circuit and method

Abstract: A drive circuit supplies a drive current to a plurality of light emitting diodes The drive circuit includes a voltage converter circuit having a particular topology and including at least one inductive element and at least one switching element The drive circuit senses a current through one of the inductive and switching elements and generates a feedback signal from the sensed current The feedback signal has a value indicating the drive current being supplied to the light emitting diodes and the drive circuit controls the operation of the voltage converter responsive to the feedback signal