scholarly journals EMC studies on systems with hybrid filter circuits for modern aircraft applications

2013 ◽  
Vol 11 ◽  
pp. 237-242 ◽  
Author(s):  
T. Kut ◽  
B. Chand ◽  
A. Lücken ◽  
S. Dickmann ◽  
D. Schulz
Keyword(s):  
Filter Design ◽  
Active Filters ◽  
Hybrid Filter ◽  
Attenuation Effect ◽  
New Approach ◽  
Electric Aircraft ◽  
Filtering Effect ◽  
Sample Measurement ◽  
Hybrid Filters ◽  
New Strategies

Abstract. In this contribution, a new approach for EMC-filter design is presented. Due to the increasing electrification of modern aircraft, as a result of the More Electric Aircraft concept, new strategies and approaches are required to fulfill the strict EMC aircraft standards (DO-160/ED-14 – Sec. 20). Consequently the weight and volume of the used filter components can be reduced. A promising approach could be a combination of passive and active filters. For the same attenuation effect, so-called hybrid filters achieve either savings in weight and volume, or can obtain an additional filtering effect with minimal weight increase of an existing system. In this paper, the underlying theory is explained in detail, carried out in a simulation tool and the gained insight is demonstrated with a sample measurement.

scholarly journals Distributed Power Quality Conditioning System for Three-Phase Four-Wire Low Voltage Networks

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4915 ◽  
Author(s):  
Valery Dovgun ◽  
Sergei Temerbaev ◽  
Maxim Chernyshov ◽  
Viktor Novikov ◽  
Natalia Boyarskaya ◽  
...  
Keyword(s):  
Power Quality ◽  
Low Voltage ◽  
Filter Design ◽  
Design Procedure ◽  
Active Filters ◽  
Hybrid Filter ◽  
Harmonic Compensation ◽  
Distributed Power ◽  
Voltage Unbalance ◽  
Three Phase

This paper presents distributed power quality conditioning system to compensate current and voltage distortions in three-phase four-wire networks caused by unbalanced non-linear single-phase loads. The proposed conditioning system consists of several hybrid filter units installed in various nodes for compensation of excessive neutral currents and voltage distortions in a selected area of the distribution network. The system is open and it can be easily modified by installation of new filter units. A novel hybrid filter design procedure based on filter frequency characteristics optimization in the parameters of passive and active parts is presented. A digital system of control signal computation for active filters based on the use of modern methods of spectral analysis is considered. The proposed digital control system enables selective compensation of fundamental and harmonic components. The mathematical model of the proposed power quality conditioning system is developed in the MatLab software. The simulated results show that the presented conditioning system reduces the level of neutral conductor currents and the voltage unbalance as well ensures harmonic compensation in three-phase four-wire networks.

scholarly journals Determination of Fetal sex by Fetal anatomy parameters using a Fuzzy C-Mean Cluster

2021 ◽  
Vol 05 (02) ◽  
pp. 9-25
Author(s):  
Wafaa Kissara ◽  
Baydaa Hassan
Keyword(s):  
Fuzzy Logic ◽  
Local Binary Pattern ◽  
Ultrasound Images ◽  
Hybrid Filter ◽  
Fetal Sex ◽  
New Approach ◽  
Color Spectrum ◽  
Visual Properties ◽  
Hybrid Filters

This paper proposes a new approach to determining the sex of the fetus using the measurement of dimensions of the head. The research attempted to use one of the techniques of fuzzy logic in the field of medicine, and here it was dealt with the visual properties designed to mix the properties of fuzzy logic (FL) and feature images. The results that some traits cannot give good results such as the results obtained from the local binary pattern (LBP) algorithm and the power and superiority of the results of hybrid filters because the ultrasound images have a special color spectrum. The results also showed the ability of the fuzzy logic proposed by using the characteristics derived from the hybrid filter to deal with the study of images and to achieve a better diagnosis of the gender of the fetus through measuring the dimensions of the head.

scholarly journals Performance comparison of hybrid active power filter for p-q theory and SVPWM technique

2021 ◽  
Vol 11 (1) ◽  
pp. 84
Author(s):  
T. M. Thamizh Thentral ◽  
K. Vijayakumar ◽  
R. Jegatheesan
Keyword(s):  
Pulse Width Modulation ◽  
Filter Design ◽  
Harmonic Distortion ◽  
Industrial Applications ◽  
Performance Comparison ◽  
Active Filter ◽  
Active Filters ◽  
Hybrid Filter ◽  
Q Theory ◽  
Source Current

Harmonic Distortion in many of the industrial applications are occur primarily owing to the enormous utilization of loads with high non-linearity like power converters, speed varying drives and arc furnaces. The power semiconductor is used to achieve the variation in speed and conversion from one source to another. Mostly active filters and tuned filters are utilized to remove the harmonic included in the source current. The tuned passive filters and inductance inserted in the line reduces the harmonics but at the same time induces the resonances in most of the industrial applications. Due to this, harmonic distortion increases in the source current and voltage. This can be reduced by adding hybrid filter in the system with decreased rating of active filter in high power applications. This article deals with the various topology of hybrid filters. The working of the proposed filter design in variable inductance mode based on the pollution created in the source voltage and current is studied. In the proposed hybrid filter passive filter is tuned with seventh harmonic frequency and connected in series with active filters to reduce the harmonic distortion. DC link voltage and the active filter VA rating could be minimized. The control signal to the filter is derived from p-q theory and space vector pulse width modulation (SVPWM). The performance of the system under study is simulated and noted for the THD percentage before and after the filter is added to the system and the same model is experimented with reduced voltage level.

scholarly journals A comparative analysis of cascaded-multilevel hybrid filters applied in power transmission systems

2008 ◽  
Vol 19 (1) ◽  
pp. 107-113 ◽  
Author(s):  
Alexandre G. Merçon ◽  
Lucas F. Encarnação ◽  
Luís F. C. Monteiro ◽  
Emanuel L. van Emmerik ◽  
Maurício Aredes
Keyword(s):  
Comparative Analysis ◽  
High Power ◽  
Power Transmission ◽  
High Harmonic ◽  
Active Filter ◽  
Active Filters ◽  
Transmission Systems ◽  
Passive Filters ◽  
Power Transmission Systems ◽  
Hybrid Filters

Passive filters, commonly used to attenuate non-characteristic harmonics in High Voltage Direct Current (HVDC) systems, stay at risk of disconnection from the system due to overcurrent problems. A possible solution to solve the problems involving high harmonic levels would be the use of pure active filters. However, this alternative is unpractical due to the high power of the transmission systems. This paper proposes two different topologies of hybrid filters to damp harmonic resonance in power transmission systems. The first one combines a small-rated active filter in series with passive filters, limiting overcurrents, when existent, or improving its own quality factor. The second one consists of an active filter in parallel with passive filters, which compensates all eventual overcurrent in the system bus. Both topologies utilizes the state of the art in very high power semiconductors and multilevel power converters. Simulation results present a comparative analysis, highlighting the efficiency of, and the differences between, the two proposed hybrid filters.

Community Crime Prevention: An Analysis of a Developing Strategy

1981 ◽  
Vol 27 (3) ◽  
pp. 405-421 ◽  
Author(s):  
Dan A. Lewis ◽  
Greta Salem
Keyword(s):  
Social Control ◽  
Crime Prevention ◽  
Theoretical Foundation ◽  
Developing Strategy ◽  
New Approach ◽  
The Social ◽  
Community Crime Prevention ◽  
Major Shift ◽  
Theoretical Foundations ◽  
New Strategies

Crime prevention strategies often aim at changing the motivations and predispositions of offenders. A new approach has developed within the last dec ade which focuses on changing the behavior of potential victims. The authors explore the theoretical foundations of the new strategies for reducing crime, commonly known as community crime prevention. They suggest that the in novation is a result of a major shift in the research paradigm for studying the effects of crime. The orientation underlying community crime prevention is labeled the "victimization perspective." Following a description of some limitations in that perspective, the authors offer, as an alternative, a perspective oriented toward social control. The social control perspective, which is based on the empirical findings of several recently completed research projects, offers a theoretical foundation both for a fresh approach to the study of the effects of crime and for the development of policies for community crime prevention.

scholarly journals New approach to finite frequency Filter Design for two-dimensional T-S fuzzy systems

2021 ◽  
Vol 297 ◽  
pp. 01036
Author(s):  
Ben Meziane Khaddouj ◽  
Abderrahim El-Amrani ◽  
Ismail Boumhidi
Keyword(s):  
Fuzzy Systems ◽  
Filter Design ◽  
Asymptotically Stable ◽  
Two Dimensional ◽  
Finite Frequency ◽  
New Approach ◽  
Filter Model ◽  
Error System ◽  
Non Linear Systems ◽  
Takagi Sugeno

This paper considers the problem of filter design for two-dimensional (2D) discrete-time non-linear systems in Takagi-Sugeno (T-S) fuzzy mode. The problem to be solved in the paper is to find a H∞ filter model such that the filtering error system is asymptotically stable. A numerical example is employed to illustrate the validity of the proposed methods.

Adaptive H2/H∞ Hybrid Filter Based on Convex Optimization

2013 ◽  
Vol 739 ◽  
pp. 586-591
Author(s):  
He Nian Wang ◽  
Guo Xing Yi ◽  
Chang Hong Wang ◽  
Yang Guang Xie
Keyword(s):  
Convex Optimization ◽  
Real Time ◽  
Filter Method ◽  
Integrated Navigation ◽  
Multiple Model ◽  
Adaptive Optimization ◽  
Hybrid Filter ◽  
Depth Analysis ◽  
Model Filter ◽  
Filtering Effect

The INS/GPS integrated navigation as the research object, based on in-depth analysis of the multiple model filter method, the convex optimization hybrid filtering method based on adaptive optimization. OLS-SVM method utilizes real-time to obtain the weighted value of the hybrid filter, enables the weight value can be varied with the real-time filtering effect of changes. Therefore, it can effectively improve the system robustness, thus affecting the estimation precision of the whole system. The simulation results show that, the method of state model instability and filter unreliable has strong adaptability, can effectively restrain the divergence of Kalman filter, which improves the system's accuracy and robustness.

Is accelerated partner therapy a feasible and acceptable strategy for rapid partner notification in the UK?: a qualitative study of genitourinary medicine clinic attenders

2009 ◽  
Vol 20 (9) ◽  
pp. 603-606 ◽  
Author(s):  
L Sutcliffe ◽  
M G Brook ◽  
J L Chapman ◽  
J M Cassell ◽  
C S Estcourt
Keyword(s):  
Partner Notification ◽  
Clinic Visit ◽  
Relationship Type ◽  
New Approach ◽  
Medicine Clinic ◽  
Limited Effectiveness ◽  
Genitourinary Medicine ◽  
The Uk ◽  
Professional Guidance ◽  
New Strategies

Partner notification (PN) in the UK is of limited effectiveness. Expedited partner therapy improves PN outcomes but does not comply with existing UK professional guidance. We developed two new strategies, known as accelerated partner therapy (APT), based on elements of PN practice for which there is evidence of efficacy, and which conform to UK prescribing guidance. We explored the acceptability and feasibility of these models qualitatively in genitourinary medicine clinic attenders. Both strategies were viewed favourably. Preference was influenced by age, relationship type, whether participants were delivering or receiving APT and whether the sex partner was aware of the participant's clinic visit. APT provides a new approach to PN, which has strong patient support and complies with existing UK regulations. The complex factors that influence patients' choice of PN method suggest that provision of a range of PN options including APT may be central to improving the effectiveness of PN in the UK.

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