A Novel Approach to Investigate the Quantitative Impact of Harmonic Currents on Winding Losses and Short Circuit Forces in a Furnace Transformer

2013 ◽  
Vol 49 (5) ◽  
pp. 2025-2028 ◽  
Author(s):  
M.A. M. Cheema ◽  
J. E. Fletcher ◽  
D. Dorrell ◽  
M. Junaid
Keyword(s):  
Short Circuit ◽  
Furnace Transformer ◽  
Harmonic Currents ◽  
Novel Approach ◽  
Quantitative Impact

scholarly journals Fuel-to-air ratio control under short-circuit conditions through UEGO sensor signal analysis

2019 ◽  
Vol 21 (9) ◽  
pp. 1577-1583
Author(s):  
Carlos Guardiola ◽  
Benjamín Pla ◽  
Marcelo Real ◽  
Cyril Travaillard ◽  
Frederic Dambricourt
Keyword(s):  
Signal Analysis ◽  
Equivalence Ratio ◽  
Short Circuit ◽  
Experimental Tests ◽  
Pollutant Emissions ◽  
Frequency Content ◽  
Novel Approach ◽  
Wide Range ◽  
The Impact ◽  
Three Way Catalyst

The impact of short-circuit pulses on the after-treatment system of a spark-ignited engine must be taken into account to keep the fuel-to-air equivalence ratio within the three-way catalyst window, thereby reducing pollutant emissions. The fuel-to-air equivalence ratio overestimation that suffers the wide-range λ-sensor upstream three-way catalyst in the presence of short circuit is especially relevant. In this study, a novel approach to deal with the fuel-to-air equivalence ratio control under short-circuit conditions is introduced. Under this scope, this work proposes a strategy for the on-board correction of the aforementioned fuel-to-air equivalence ratio overestimation, by means of the information regarding short-circuit level that provides the frequency content of the λ-sensor at the engine frequency. Finally, the potential of this approach to minimize pollutant emissions, in particular the NO x penalty arisen as a consequence of running the engine under leaner conditions than expected, is assessed through experimental tests.

scholarly journals Identification of Inter-Turn Short-Circuits in Induction Motor Stator Winding Using Simulated Annealing

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 117
Author(s):  
Marcin Tomczyk ◽  
Ryszard Mielnik ◽  
Anna Plichta ◽  
Iwona Goldasz ◽  
Maciej Sułowicz
Keyword(s):  
Simulated Annealing ◽  
Induction Motor ◽  
Induction Motors ◽  
Early Stage ◽  
Dynamic Properties ◽  
Short Circuit ◽  
State Variables ◽  
Novel Approach ◽  
Short Circuits ◽  
Identification Processes

This paper presents a method of inter-turn short-circuit identification in induction motors during load current variations based on a hybrid analytic approach that combines the genetic algorithm and simulated annealing. With this approach, the essence of the method relies on determining the reference matrices and calculating the distance between the reference matric values and the test matrix. As a whole, it is a novel approach to the process of identifying faults in induction motors. Moreover, applying a discrete optimization algorithm to search for alternative solutions makes it possible to obtain the true minimal values of the matrices in the identification process. The effectiveness of the applied method in the monitoring and identification processes of the inter-turn short-circuit in the early stage of its creation was confirmed in tests carried out for several significant state variables describing physical magnitudes of the selected induction motor model. The need for identification of a particular fault is related to a gradual increase in its magnitude in the process of the induction motor’s exploitation. The occurrence of short-circuits complicates the dynamic properties of the measured diagnostic signals of the system to a great extent.

Current modeling in a bus packet of a high-current system

2020 ◽  
pp. 40-44
Author(s):  
T.A. Novozhilov ◽  
A.N. Novozhilov ◽  
D.M. Rahimberdinova
Keyword(s):  
Mathematical Model ◽  
Single Phase ◽  
Current System ◽  
Short Circuit ◽  
High Current ◽  
Furnace Transformer ◽  
Simulation Error ◽  
Flexible Connections ◽  
Split Winding ◽  
Secondary Winding

A graphoanalytic method for determining the highcurrent system resistances and a mathematical model of a single-phase furnace transformer with a split secondary winding are developed for modeling currents in a transformer and a high-current system bus package in case of short circuit and opening of flexible connections. Experiments have proved the adequacy of the proposed method. The simulation error does not exceed 10 %. Keywords: single-phase transformer, split winding, short circuit, high-current system, opening, resistance, mathematical model, modeling. [email protected]

The fate of infiltrated stormwater from infiltration basins to the stream: quantifying the impact of the urban karst

2020 ◽  
Author(s):  
Abolfazl Poozan ◽  
ََAndrew Western ◽  
Meenakshi Arora ◽  
Matthew Burns ◽  
Tim Fletcher
Keyword(s):  
Short Circuit ◽  
Control Measures ◽  
Sewer Pipes ◽  
Groundwater Levels ◽  
Novel Approach ◽  
Wide Range ◽  
Underground Infrastructure ◽  
Receiving Waters ◽  
Stormwater Control Measures ◽  
The Impact

<p>Urbanization leads to severe alterations to the flow regime of receiving waters, including increased frequency and magnitude of storm flows as well as reduced baseflows. Infiltration basins are among the most widely applied stormwater control measures worldwide, in part for their ability to intercept stormwater runoff and allow it to infiltrate into the ground, with the assumption that this will recharge groundwater and thus help in restoring clean, filtered baseflows to receiving waters. Recent research has highlighted that in fact, the fate of infiltrated stormwater is highly uncertain, particularly because of likely interactions with underground infrastructure—e.g. sewer pipes, telecommunication cables, etc. These infrastructures are typically surrounded by highly permeable material which has the potential to substantially alter the way infiltrated stormwater moves through the subsurface (a phenomenon known as the urban karst).</p><p>This study aimed to predict and generalize the impact of the urban karst on infiltrated stormwater as it can provide a preferential flowpath and thus may prevent infiltrated stormwater from reaching receiving waters or may short circuit subsurface storages that can increase routing time delays and thus baseflow. In doing so, a modelling study using HYDRUS-3D was undertaken. In addition, a novel approach to generalize the results was proposed based on groundwater level and the hydraulic conductivities of soil and gravel/sand. We predicted that the impact of the urban karst on infiltrated stormwater increases whit higher groundwater levels, and greater contrasts between the hydraulic conductivity of regional soil and gravel. The HYDRUS results for a wide range of scenarios are compared with the generalization, which captures the impact of Urban Karst well.</p><p>It is important to consider the impact of the urban karst where one of the goals of building infiltration basins is to recharge the baseflow of the stream downslope. This suggests that decision on basin location is important where urban infrastructure is located between potential infiltration basin sites and downslope stream. The impact of the urban karst should be investigated at each specific site before implementing infiltration systems and this study works towards simplified representations of impact for design.</p>

scholarly journals Reducing of total harmonic distortion by simulating passive filters to suppress harmonic currents with the case: Faculty of Engineering Building, Universitas Kristen Indonesia Jakarta

2021 ◽  
Vol 878 (1) ◽  
pp. 012060
Author(s):  
A D T Prasetyo ◽  
E M Silalahi ◽  
S Stepanus ◽  
B Widodo ◽  
R Purba
Keyword(s):  
Filter Design ◽  
Short Circuit ◽  
Harmonic Distortion ◽  
Maximum Load ◽  
Total Harmonic Distortion ◽  
Laboratory Equipment ◽  
Harmonic Currents ◽  
Measurement Results ◽  
Passive Filters ◽  
Sinusoidal Current

Abstract Today’s electrical appliances use power electronics to save electricity. However, this equipment generates non-sinusoidal current, causing wave defect, expressed as total harmonic distortion (THD). As the %THD increases, the greater risk of equipment damage. For this reason, the research was carried out in the Faculty of Engineering Building, Universitas Kristen Indonesia Jakarta (FT UKI Jakarta) where there are many load combinations such as computers, various types of lights, laboratory equipment such as transformers, electric motors and so on. The research was conducted using quantitative method. Data collection is carried out directly in the main panel. Based on the measurement results, the calculation of the maximum load current (IL) and short circuit (ISC) is carried out. Through these values, it can be seen that whether the odd dominant harmonic values and orders meets the IEEE 519-2014 standards or not. Calculations and analysis of the measurement results have shown that the %THDI in the FT UKI building has not meet the standard. Therefore, it is necessary to simulate the filter design to reduce the %THDI, so that the results can meets the IEEE 519-2014 standard, which is below 5%.

scholarly journals Photovoltaic Cell and Module I-V Characteristic Approximation Using Bézier Curves

2018 ◽  
Author(s):  
Roland Szabo ◽  
Aurel Gontean
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
Photovoltaic Cell ◽  
Open Circuit ◽  
Maximum Power ◽  
Shunt Resistance ◽  
First Case ◽  
Novel Approach ◽  
Pv Cell ◽  
Different Temperatures

The aim of this work is to introduce new ways to model the I-V characteristic of a PV cell or PV module using straight lines and Bézier curves. This is a complete novel approach, Bézier curves being previously used mainly for computer graphics. The I-V characteristic is divided in three sections, modeled with lines and a quadratic Bézier curve in the first case and with three cubic Bézier curves in the second case. The result proves to be accurate and relies on the fundamental points usually present in the PV cell datasheets: Voc (the open circuit voltage), Isc (the short circuit current), Vmp (the maximum power corresponding voltage) and Imp (the maximum power corresponding current) and the parasitic resistances Rsh0 (shunt resistance at Isc) and Rs0 (series resistance at Voc). The proposed algorithm completely defines all the implied control points and the error is analyzed. The proposed method is validated for different temperatures and irradiances. The model is finally compared and validated using the least squares fitting method.

scholarly journals Photovoltaic Cell and Module I-V Characteristic Approximation Using Bézier Curves

2018 ◽  
Author(s):  
Roland Szabo ◽  
Aurel Gontean
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
Photovoltaic Cell ◽  
Open Circuit ◽  
Maximum Power ◽  
Shunt Resistance ◽  
First Case ◽  
Novel Approach ◽  
Pv Cell ◽  
Straight Lines

The aim of this work is to introduce new ways to model the I-V characteristic of a PV cell or PV module using straight lines and Bézier curves. This is a complete novel approach, Bézier curves being previously used mainly for computer graphics. The I-V characteristic is divided in three sections, modeled with lines and a quadratic Bézier curve in the first case and with three cubic Bézier curves in the second case. The result proves to be accurate and relies on the fundamental points usually present in the PV cell datasheets: Voc (the open circuit voltage), Isc (the short circuit current), Vmp (the maximum power corresponding voltage) and Imp (the maximum power corresponding current) and the parasitic resistances Rsh0 (shunt resistance at Isc) and Rs0 (series resistance at Voc). The proposed algorithm completely defines all the implied control points and the error is analyzed. The temperature and irradiance influence is also analyzed. The model is also compared using the least squares fitting method. The final validation shows how to use Bézier cubic curves to accurately represent the I-V curves of an extensive range of PV cells and arrays.

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