Integrated series active filter for aerospace flight control surface actuation

The paper investigates integrated series active filters to satisfy aircraft power quality benchmarks and underlying design compromises. Advantages include reduced component count and retrofitting capability. Further insights into the merits of the proposed solution are included, along with representative results from a prototype system

Multilevel Converters: An Enabling Technology for High-Power Applications

| Multilevel converters are considered today as the state-of-the-art power-conversion systems for high-power and power-quality demanding applications. This paper presents a tutorial on this technology, covering the operating principle and the different power circuit topologies, modulation methods, technical issues and industry applications. Special attention is given to established technology already found in industry with more in-depth and self-contained information, while recent advances and state-of-the-art contributions are addressed with useful references. This paper serves as an introduction to the subject for the not-familiarized reader, as well as an update or reference for academics and practicing engineers working in the field of industrial and power electronics.Ministerio de Ciencia y Tecnología DPI2001-3089Ministerio de Eduación y Ciencia d TEC2006-0386

Passivity-based harmonic control through series/parallel damping of an H-bridge rectifier

Nowadays the H-bridge is one of the preferred solutions to connect DC loads or distributed sources to the single-phase grid. The control aims are: sinusoidal grid current with unity power factor and optimal DC voltage regulation capability. These objectives should be satisfied, regardless the conditions of the grid, the DC load/source and the converter nonlinearities. In this paper a passivity-based approach is thoroughly investigated proposing a damping-based solution for the error dynamics. Practical experiments with a real converter validate the analysis.

Impact of harmonic voltage distortion on the voltage sag behavior of adjustable speed drives

The behavior of adjustable speed drives under voltage sag conditions and supplied form non-sinusoidal voltage waveforms has received little attention in recent years. This paper shows that voltage harmonic distortion has a major impact on the drive behavior. The impact of voltage sag conditions, including harmonics is represented by means of voltage tolerance curves. To overcome the impact, a fast field weakening control scheme for field oriented induction motor drives is analyzed

Analysis of the power balance In the cells of a multilevel cascaded H-Bridge converter

Multilevel cascaded H-Bridge converters (CHB) have been presented as a good solution for high power applications. In this way, several control and modulation techniques have been proposed for this power converter topology. In this paper the steady state power balance in the cells of the single phase two cell CHB is studied. The capability to be supplied with active power from the grid or to deliver active power to the grid in each cell is analyzed according to the dc-link voltages and the desired ac output voltage value. Limits of the maximum and minimum input active power for stable operation of the CHB are addressed. Simulation results are shown to validate the presented analysis

A comparative study of electric power distribution systems for spacecraft

The electric power distribution systems for spacecraft are compared concentrating on two interrelated issues: the choice between dc and high frequency ac, and the converter/inverter topology to be used at the power source. The relative merits of dc and ac distribution are discussed. Specific converter and inverter topologies are identified and analyzed in detail for the purpose of detailed comparison. Finally, specific topologies are recommended for use in dc and ac systems

High Power Factor Hybrid Rectifier

This paper presents the analysis of a new single-phase hybrid rectifier with high power factor (PF) and low harmonic distortion current. The proposed rectifier structure is composed of an ordinary single-phase diode rectifier with parallel connection of a switched converter. It is outlined that the switched converter is capable of shaping the input line current waveform, assuring high PF and low total harmonic distortion (THD). The power rating of the switched converter is less than 50% of the total output power; assuring reliability in the proposed hybrid rectifier. A pulse width modulation (PWM) control strategy was developed, imposing quasi-sinusoidal line input current waveform and limiting the switched converter power contribution. It was found that the line input current harmonic spectrum is in accordance with the harmonic limits imposed by IEC61000-3-4. The principle of operation, the mathematical analysis, and simulated results are also presented in the paper.http://dx.doi.org/10.4314/njt.v33i4.

Kesan penularan wabak Covid-19 terhadap sektor perumahan dari perspektif kemampuan pemilikan rumah

Rumah menjadi hak setiap individu seperti termaktub dalam Universal Declaration of Human Rights 1948 : Everyone has a right to a standard of living adequate for the health and well-being of himself and of his family, including food, clothing, housing and medical care and necessary social services and the right to security in the event of unemployment, sickness, disability, widowhood, old age or the lack of livelihood in circumstances beyond his control. (United Nations, 1948) Kemampuan perumahan menjadi agenda penting bagi majoriti negara di peringkat global. Keperluan manusia untuk mempunyai rumah sebagai keperluan asas yang perlu dipenuhi meletakkan isu kemampuan perumahan sentiada diberi tumpuan dan dibahaskan sepanjang tahun..

Design Of A Single Phase Unity Power Factor Switch Mode Power Supply (SMPS) With Active Power Factor Correction [TK7881.15. N335 2008 f rb].

Pembekal kuasa mod pensuisan (SMPS) merupakan satu industri yang bernilai jutaan ringgit dan berkembang pesat dalam bidang elektronik kuasa. The Switch Mode Power Supplies (SMPS) are a multi-million dollar industry and continuesly growing industry within the field of power electronics