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High Impedance Fault (HIF) has long been a challenging problem in network protection. This is because of its difficulty to be detected and discriminated accurately and reliably. In real cases, arcing is usually associated with HIFs. In this paper, arcing currents are produced by setting up a HV experiment. Normal switching transients are also produced by simulation or experiment. They are then analysed...
Distribution Systems (DS) are usually structured as weakly-meshed but the majority of them operate with a radial topology, mainly in order to accommodate the protection coordination. Obtaining the optimal radial configuration under several criteria has been an active research topic for more than two decades. Because of the computational burden and the non-linearity of the problem, the majority of...
A 4-channel analog front-ends designed for neural signal acquisition is demonstrated in this paper. Each channel consists of a high input impedance, high gain, low noise and high linearity amplifier and a high precision Σ-Δ analog to digital convertor (ADC). The amplifier is realized with a capacitive feedback closed loop op-amp. Fabricated in 180nm CMOS process, the 4-channel system occupies 2.34mm...
Amongst the many innovations for improving grid performance and stability is the concept of Fast-Timescale Demand Response (FTDR), which is particularly suited for appliances which have the capacity to store energy in the short term. In particular, domestic thermostatically-controlled loads (TCL), such as air-conditioners, are excellent candidates for FTDR. FTDR has the potential to reap financial...
Future smart grids (SGs) are expected to include distributed generations (DG), plug-in electric vehicles (PEVs) and smart appliances, as well as nonlinear industrial loads that may decrease grid efficiency and deteriorate the quality of electric power. This paper performs optimal (load tap changer)LTC and switched shunt capacitor (SSC) in SGs with nonlinear loads, wind distributed generation (WDGs)...
Due to the low reserve margin on the electrical grid in South Africa many energy initiatives were introduces by the utility over the last decade. One such initiative was to roll out identified energy efficiency technologies at residential homes. The utility aimed to achieve a 90MW evening peak (18h00 to 20h00) demand reduction by distributing free CFLs, LEDs, geyser timers, pool timers and low flow...
Integrated-magnetic interleaved boost converters are under development for high-current, high-power applications ranging from automotive to distributed generation. The operating modes of these integrated-magnetic converters are complex and are also a function of the conduction of the lower inverse diode. A reverse-blocking diode or RB IGBT may be preferred for the lower switch, which introduces additional...
A new space vector modulation (SVM) strategy is proposed for quasi-Z-source indirect matrix converter (QZS-IMC) to reduce common-mode voltage and to ensure a high voltage transfer ratio. QZS-IMC's common-mode voltage is analyzed, and the subdivided sectors are employed to rearrange switching sequence in the inverter stage, which can reduce common-mode voltage and power loss. The proposed modulation...
Power consumption is a major concern in nearly all systems, from data centers to portable devices and medical implants. Consequently, effective power management is increasingly important to designers working in a wide range of application domains. This session collects eight papers addressing the most recent advances in circuits and control strategies for power management.
In this paper, we proposed an algorithm to discovery physical layer topology structure of Ethernet networks with incomplete address forwarding table information by collecting data via SNMP. The new algorithm is also able to handles VLANs and layer-3 switches. We have implemented our algorithm in networks of Beijing University of Posts and Telecommunications which demonstrated that our algorithms works...
This paper presents a novel low voltage DC/DC boost converter for energy harvesting from ultra-low power energy sources. The proposed converter has a simple structure consisting of two stages: an autonomous oscillator in the first stage enabling self-starting of converter and a controllable reverse buck-boost converter in the second stage. Simulation results and experimental tests proved that this...
While Web browsers are fundamental components in the Internet nowadays, the widespread availability of several techniques that can be used to detect the individual browser connected to a server raises privacy issues that need to be adequately addressed. Browser fingerprinting uses a combination of attributes, whose values are silently obtained during normal navigation, to identify, with high likelihood,...
We performed an experimental study (n=48) of the effects of context congruency on human perceptions of robotic facial expressions across cultures (Western and East Asian individuals). We found that context congruency had a significant effect on human perceptions, and that this effect varied by the emotional valence of the context and facial expression. Moreover, these effects occurred regardless of...
Performance of software is increasingly restricted by the Memory Wall instead of CPU. Many studies focus on alleviating the DRAM latency by improving the row-buffer hit rate. But most of them treat the Kernel and User equally. Data used by Operating System and User applications spread in different rows of the same bank, leading to the contentions for the row-buffer when they access the bank successively...
Network speeds, wireless communications and rapid graphic processors now allow the collection and rendering of information in ways previously not possible. Together with this, convergence of many sources of disparate events, including tracking over geospatial domains and interaction with sensors, allow for processing of real time data which can be communicated between both real and virtual worlds...
Coupled inductors have lately been used with impedance-source networks for keeping their shoot-through times short, while providing higher voltage boosts. The parameter that is critical to the operation of such impedance network based converter with coupled inductors is the leakage inductances. However, the role of leakage inductances and its effect on the converter performance is often overlooked...
This paper presents a novel interleaved multiphase hybrid boost DC/DC converter. This converter type provides high efficiency and can be used for applications with wide voltage conversion ratio. At the beginning, the circuit function and the design of a single-phase converter is described. With a multiphase design, the filter circuit effort can be significantly reduced. In these circuits the different...
This paper presents a state-space (subspace) method for identification of parallel-cascade joint stiffness from short segments of data. It provides unbiased estimates of stiffness by accounting for the contributions of initial conditions of each segment. The method is important in situations where it is not possible to acquire a long stationary data due to switching or time-varying behavior. The power...
A global sliding mode controller (GSMC) based on disturbance observer (DOB) is proposed for motor servo systems which are widely used, but whose performance is vulnerable to external disturbances and parameter variations. The initial state of the system is set on the sliding surface by employing an integral switching function, and by applying linear quadratic regulator (LQR) optimal theory, the sliding...
A novel two rank hybrid iterative quasi-sliding mode control strategy is present for a class of uncertain nonlinear systems. In the first rank of sliding mode switch function, a reference trending function is introduced, which eliminated the reaching stage of sliding mode controller; The second rank of sliding mode switch function iterate based on the first one, and a hyperbolic tangent function is...
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