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Voltage disturbances in power systems are caused by various events such as faults or control actions. It is important to accurately identify them for fast remedial response and damage prevention. Recently, data mining techniques have been applied in power system research, usually from the perspective of the entire system. The analyzed data include measurements from transmission buses, substations,...
This paper introduces the design of a Marx Generator that can generate high attitude pulses up to 25 kV and 2.5 kA. The pulses have a wave shape representative of that used to test High-altitude ElectroMagnetic (HEMP) filters against the pulse current injection (PCI) requirements. The rise time is 20 ns and the pulse width is 230 ns on a 10 Ω resistor. In the design, it was found that parasitic effect...
The U.S. Coast Guard's 270-ft Medium Endurance Cutter (WMEC) is a powerhouse of the Coast Guard fleet filling a critical role in defense of the homeland. While the U.S. Navy has conducted extensive research into the use of zonal DC electrical distribution systems (DCDS) for their ships, no project has analyzed the installation of DCDS on a Coast Guard cutter which has a significantly different load...
The content of this paper will illustrate how, in the future, the power transmission system in Great Britain (GB) may be much “weaker” than it is at present, and will describe the potential impact that this could have on the voltage profiles during faults, and how the operation of backup protection system operation, if required, needs to be considered carefully to ensure system integrity in the future...
Grid-tied small wind turbines based on permanent magnet generators are usually operated using a basic converter topology based on a passive rectifier, a boost converter, and an H-bridge inverter. The rotor speed signal is rarely obtained from speed or position sensors in this kind of systems. Model-based estimators are rather used for this purpose relying on electrical magnitudes. Despite its complexity...
This paper analyzes a cost-effective modification of the rectifier plus boost converter power topology which is commonly found in small wind turbine systems. The paper proposes removing the input capacitor after the rectifier and the boost converter inductance. This will be done without adding any LC filter between the permanent magnet generator and the passive rectifier. This paper discusses both...
The structure of rotating diode rectifier were proposed in this paper to solve the excitation problem of brushless wound-rotor synchronous starter/generator. Rotating diode rectifier plays an important part of excitation system of main generator. Triple Rectifier was adopted to take the place of three-phase rectifier. The three phase armature windings connect to a full-bridge rectifier each other...
In aircraft applications, there has been an increasing trend related with the More Electric Aircraft (MEA), which results in rapid rise in the electrical power demand on-board. One of its goals lies in minimizing weight and volume of the electrical subsystem while maintaining good power quality and efficiency. The main purpose of this paper is to present and analyze an electrical design of a three-phase...
UHVDC(ultra high voltage direct current) is an important method for State Grid Corporation of China to achieve inter-regional long-distance power transmission. ± 1600kV ultra high voltage DC generator is an important equipment to provide high voltage DC test voltage, mainly used for testing the DC electrical equipment. In order to guarantee the safe operation of DC transmission equipment, Using electric...
Direct lightning strikes to human heads lead to various effects ranging from Lichtenberg figures, over loss of consciousness to death. The evolution of the induced current distribution in the head is of great interest to understand the effect mechanisms. This work describes a technique to model a simplified head-phantom to investigate effects during direct lightning strike. The head-phantom geometry,...
This paper presents a novel distributed neural stimulator scheme. Instead of a single stimulator ASIC in the package, multiple ASICs are embedded at each electrode site for stimulation with a high density electrode array. This distributed architecture enables the simplification of wiring between electrodes and stimulator ASIC that otherwise could become too complex as the number of electrode increases...
This paper presents a general framework based on the RST structure for performing fair comparisons between deterministic and stochastic digital linear controllers. Due to the chosen RST formulation, it can be shown that any linear Single-Input Single-Output controller may be designed as a Generalized Minimum Variance Controller, i.e. as a stochastic controller. This in particular reduces the variance...
It is notable that the air discharge method specified in the International Eelectrotechnical Commission (IEC) standard provides unstable testing reproducibility. In this paper, to achieve stable testing reproducibility, we proposed an alternative air discharge test method using an electrostatic discharge (ESD) generator in contact discharge mode. Measurements of air discharge currents through a fixed...
Wide-area measurement-based voltage stability assessment (VSA) by coupled single-port circuit models has been widely discussed recently. This method models the coupling effects of load buses within a meshed network into extra impedance of a single-port model for each load bus. In simulation studies, overestimations of voltage stability margin using this approach have been observed when critical load...
This paper studies physical consequences of worst-case unobservable false data injection (FDI) attacks on the electric power system. In particular the focus is on FDI attacks wherein the attacker can only change measurements in an attack sub-network of the entire network and has limited knowledge of network parameters outside of this sub-network. The goal of this limited resource attack is to cause...
Compact pulsed power generators have been used in fields such as biology, environment, and agriculture. Functions required by researchers include miniaturization, weight saving, safety, and ease-of-use. Recently, control systems using microcomputers or field programmable gate arrays (FPGA) have been studied for flexibility in changing circuits and greater control of pulse power. Because various uses...
In this work, lightning discharges and their effects on control & communication cables and antenna systems are investigated. The mechanism of lightning is described in detail and electric fields created by lightning discharges are examined. An experimental test setup is designed and implemented in order to observe induced voltages on cables or antennas caused by lightning discharges. Test results...
As part of the LHC Injector Upgrade (LIU) project, the production of a high-intensity proton beam in the Proton Synchrotron Booster (PSB) at CERN will be achieved by injecting a beam of H− ions from the new linear accelerator LINAC4. During the injection process the two electrons of the H− ions are removed with a stripping foil across which the machine orbit is shifted to fill the machine aperture...
The paper presents a method for monitoring and diagnosis of the effects yielded by the non-sinusoidal regime over the voltage transformers operating in a power group. The analyzed schematic structure is presented along with all its components. Information on the designing, construction and implementation of a data acquisition system (DAS) are presented, along with the interface for data visualization...
Propagation delay variation of the threshold detection comparator in current-day level-crossing ADCs is a fundamental impediment to their performance. This paper reviews why commonly used threshold detection comparators can be inappropriate to detect level crossing times of high-frequency signals. The analysis presented in this paper helps establish a new common ground for developing a high-performance...
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