Robust simulation is essential for reliable operation and planning of transmission distribution power grids. At present, disparate methods exist steady-state analysis the (power flow) grid (three-phase flow). Due to non-linear nature problem, it difficult alternating current (AC) flow three-phase analyses ensure convergence correct physical solution, particularly from arbitrary initial conditions, or when evaluating a change (e.g. contingency) in grid. In this paper, we describe our...

Robust solving of critical large power flow cases (with 50k or greater buses) forms the backbone planning and operation any connected grid. At present, reliable convergence with applications existing tools to systems is contingent upon a good initial guess for system state. To enable robust scale starting an arbitrary guess, we extend our equivalent circuit formulation analysis include novel continuation method based on transmission line (Tx) stepping. While various methods have been...

Recent development of techniques that improve the convergence properties power flow simulation have been demonstrated to facilitate scaling large system sizes (80k+ buses). However, problem remains reliably identify cases are infeasible - configurations no solution. In this paper, we use circuit theoretic approach based on adjoint networks evaluate feasibility a test case and further locate quantify source infeasibility in operating beyond tip nose curve. By creating current models added...

The main factors of fine bubble aeration systems in uniform arrangement clean water are the air flow rate, depth submergence diffusers, and diffuser density. While influence rate on oxygen transfer parameters is known, knowledge density specific efficiency SOTE [%/m] absorption SOA [g/m 3 ·m at STP] very limited. Both great importance dimensioning systems. Therefore, a literature review was conducted to show type blower efficiency. results are, that higher values can be obtained density;...

In order to fulfill the grid codes and meet power quality requirements in grid-connected converters without increasing switching frequency or system size, higher line filters are often used. This paper considers active damping of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">$LC\!L$</tex-math></inline-formula> -filters converters. Analysis discrete time domain shows that can be increased when proportional...

The main factors of fine bubble aeration systems in uniform arrangement clean water are the air flow rate, depth submergence diffusers, and diffuser density. While influence rate on oxygen transfer parameters is known, knowledge density specific efficiency SOTE [%/m] absorption SOA [g/m3·m at STP] very limited. Both great importance dimensioning systems. Therefore, a literature review was conducted to show type blower efficiency. results are, that higher values can be obtained density;...

A locally autoadaptive image sensor LARS II (Lokal-AutoadaptiveR Sensor) with 368/spl times/256 pixels was designed and fabricated in thin film on ASIC (TFA) technology. Every pixel contains an automatic shutter, made of 17 transistors two capacitors area 40/spl times/38.3 /spl mu/m/sup 2/, that adapts the integration time to local intensity. This allows capture processing scenes extremely high dynamic range. For amorphous detector system, contrast temperature stability are demonstrated be...

Lateral charge diffusion in back-illuminated CCDs directly affects the point spread function (PSF) and spatial resolution of an imaging device. This can be particular concern thick, CCDs. We describe a technique measuring this present PSF measurements for 800/spl times/1100, 15 /spl mu/m pixel, 280 back-illuminated, p-channel CCD that over-depleted. The is measured over wavelength range 450 nm to 650 at substrate bias voltages between 6 V 80 V.

Oxygen transfer rates of fine bubble aeration systems in uniform arrangement are reduced down to 40% 70% wastewater compared clean water conditions. Surfactants the main reason for inferior and therefore uneconomic performance. The influence different types surfactants (anionic nonionic) their concentration on oxygen is investigated at various properties pure (content electrolytes, hardness) by means extensive experiments. results investigations are:in dependence type surfactant, its water:–...

Resistance spot welding uses direct current in the range of 1 kA to more than 100 join sheet metals. The is provided by an inverter that connected a dc-link capacitor and transformer with high turns ratio. rectified at secondary side transformer. Since voltage between tips electrodes only few Volts drop across rectifier diodes contributes losses therefore low efficiency. This paper presents new frequency optimized for applications, which consists submodules planar transformers integrated...

A thin film on ASIC (TFA) image sensor is fabricated depositing an amorphous silicon thin-film detector onto a CMOS ASIC. With regards to advanced imaging systems, TFA provides enhanced performance and more flexibility than conventional technologies. Extensive on-chip signal processing feasible, as well small pixels for high resolution imagers. Two new imager prototypes have recently been fabricated. High-resolution (HIRISE II) with 1024/spl times/128 active pixel suited digital photography....

This paper presents a new, simple and low cost method for fast short circuit protection of IGBT modules. The principle the is to measure voltage across inductance between power-emitter auxiliary-emitter. Moreover, by modulating gate-signal, new reduces gate emitter V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ge</inf> in order limit current allows semiconductor be operated safe operation area. concept has been implemented unit, which...

This paper presents a new method for balancing currents of two or more parallel-connected IGBTs during an on-state the switches, wherein each semiconductor is controlled by its own gate unit. Moreover, imbalance collector are estimated measuring voltage across inductance between power-emitter and auxiliary-emitter semiconductor. The control algorithm has been implemented in FPGA. Experimental results have obtained, with use buck converter 650 A/1700 V connected parallel.

This paper describes how to utilize physics-based unified modeling of complex electric power systems in order design a multi-layered interactive Smart Grid Room Simulator (SGRS). In this simulator, the dynamic response given interconnected grid is simulated and assessed as family interfaced sub-processes jointly evolving at different time-scales. Compared state-of-the-art simulators, advantages SGRS are that it scalable large since uses distributed computing allows for privacy components one...

In order to fulfill the grid codes and meet power quality requirements in connected converters without increasing switching frequency or system size, higher line filters are used. This paper considers active damping of LCL converters. The proportional feedback last two samples filter capacitor current for purpose is analyzed discrete time domain. A simple numerical design algorithm proposed an analytical solution derived a special case. new allows optimal uncontrolled closed loop with...

An Equivalent Circuit Programming (ECP) approach that expresses the optimality conditions of an optimization problem in terms equivalent circuit model and uses simulation techniques to solve for optimal solution, is applied state estimation power systems. The benefits using formulation incorporating both Phasor Measurement Units (PMU) Remote Terminal (RTU), as well reducing nonlinearities was previously demonstrated. In this paper we further exploit nature formulate not only but also ECP...

In upgrading or extending activated sludge treatment plants, there is a trend to apply deeper (8 12 m) aeration tanks than until now (4 6 m). Such consume less area, need air and produce off-gas. Sometimes, greater efficiency (kg O2/kWh) hence energy savings are expected. On the other hand, not sufficient experience safely design diffusion systems for deep tanks. Based on physics of gas transfer, model simulation oxygen transfer in developed. The simulated data allow quantitative conclusions...

Recent advances have shown that the circuit simulation algorithms allow for solving highly nonlinear circuits of over one billion variables can be applicable to power system and optimization problems through use an equivalent formulation. It was demonstrated large-scale (80k+ buses) flow simulations robustly solved, independent initial starting point. In this paper, we extend electronic circuit-based G-min stepping homotopy method simulations. Preliminary results indicate proposed algorithm...

Resistance spot welding is a commonly used industrial process. A low efficiency of the inverter, transformer and rectifier lead to high operation costs bulky cooling system. This work investigates new with integrated synchronous rectification that significantly increases system decreases size weight, therefore offers lower for energy, system, rectifier. modulation scheme proposed thermal behavior are presented.

Simulating potential cascading failures can be useful for avoiding or mitigating such events. Currently, existing steady-state analysis tools are ill-suited simulating outages as they do not model frequency dependencies, require good initial conditions to converge, and unable distinguish between a "collapsed grid state" from "hard-to-solve test case." In this paper, we extend circuit-theoretic approach the of power incorporate deviations implicit models under-frequency under-voltage load...

Recent development of techniques that improve the convergence properties power flow simulation have been demonstrated to facilitate scaling large system sizes (80k+ buses). However, problem remains reliably identify cases are infeasible, configurations no solution. In this paper, we use circuit theoretic approach based on adjoint networks evaluate feasibility a test case and further locate quantify source infeasibility in operating beyond tip nose curve. By creating current models added each...