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55th International Universities Power Engineering Conference (UPEC)

作者： Kazemirova, Yulia Anuchin, Alecksey Kovyazin, Alexey Lashkevich, Maxim Aliamkin, Dmitry Grishin, Sevastyan Moscow Power Engn Inst Dept Elect Drives Moscow Russia Vector Elect Equipment Plant LLC Votkinsk Russia

ISBN: (纸本)9781728110783

Medium voltage frequency converters generally utilize low-voltage multi-cell topology. The cascaded connection between their cells allows them to multiply effective pulse-width modulation (PWM) frequency by the number of cells. However, available PWM techniques have some limitations, such as time delayed operation which limits current loop response time, need for reinitialization of the PWM carriers in case of cell failure, or the unequal distribution of losses. To solve these sets of problems, the PWM strategy was introduced, which utilizes PWM in a single cell with sequential cell switching. This PWM strategy can operate in case of partial inverter failures, provide maximum available voltage to the load, and has a low response time due to a single cell operating at high PWM frequency while the average switching frequency is limited. The proposed PWM technique was examined using a model where the distribution of the switching losses and high quality of the output voltage were confirmed.

关键词： medium voltage frequency converter multi-level inverter pulse-width modulation low-voltage cell

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Determination of the Voltage Coefficients of the Six-Switch AC/AC Converter Based on Static Utilization Factor 46

Determination of the Voltage Coefficients of the Six-Switch ...

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46th Annual Conference of the IEEE-Industrial-Electronics-Society (IECON)

作者： Cury Alves dos Santos, Stefan Thiago Ubaldo Guazzelli, Paulo Roberto de Castro, Allan Gregori Vieira, Bruno Freitas Pinto, Saulo de Andrade de Aguiar, Manoel Luis Univ Sao Paulo Sao Carlos Sch Engn Sao Carlos Brazil

ISBN: (纸本)9781728154145

The six-switch AC/AC converter (SSC) is a suitable replacement of the back-to-back converter (B2B) for low-voltage and low-power usages. Its benefits include an increase in reliability due to its reduced number of switches, at cost of an increased DC bus voltage. An important step of the SSC implementation is the design of the DC voltage distribution ratio across the three DC bus sections in this converter, although it is not clear in the literature the freedom for setting these values, denominated voltage coefficients, nor the way to improve the DC bus utilization with fixed offset values. This paper presents some guidelines to establish DC bus voltage coefficients and introduces a new method to improve the DC bus utilization. Simulation results show that this new method has similar performance compared to the most used method in literature, and allows a reduction of the needed DC bus voltage according to the static voltage utilization factor.

关键词： six-switch converter pulse-width modulation reduced switch count converters

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Selection an Effective Implementation of a Multiphase Isolated DC-DC Converter 4

Selection an Effective Implementation of a Multiphase Isolat...

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4th IEEE International Conference on Intelligent Energy and Power Systems (IEPS)

作者： Kolosov, V., I Vasechko, E. V. Scientifically Mfg Enterprise Impuls Zaporozhe Ukraine

ISBN: (纸本)9780738105680

A study was made of the power loss in the active elements (transistors, diodes) of several circuit designs of a multiphase isolated DC-DC converter with the number of phases from two to five in the range of multiple changes in the supply voltage. The switching processes in a multiphase circuit with a different number of phases on the intervals of the operating values of the current pulse duty ratio are considered. The conditions for comparing the power of losses in the active elements of circuit designs are determined. Comparison of the power of losses in the designs is proposed by the equivalent element method, which ensures the equivalence of the schemes. Analytical expressions of the current shape coefficient are given, as well as analytical and graphical dependences of the relative power loss in transistors and diodes for a fixed and variable supply voltage. A comparative analysis of the power loss in the elements identified the most effective schemes of three and four phase versions of the converter.

关键词： multiphase converter pulse-width modulation power loss in active elements the rate of change of the supply voltage

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Output Perfect Tracking Control for a Plant with PWM-Type Input 21st

Output Perfect Tracking Control for a Plant with PWM-Type In...

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21st IFAC World Congress on Automatic Control - Meeting Societal Challenges

作者： Tamekuni, Kohta Suzuki, Masayasu Hirata, Mitsuo Utsunomiya Univ 7-1-2 Yoto Utsunomiya Tochigi 3218585 Japan

It is a well-established fact that an unstable zero may appear when a minimum-phase continuous-time system is discretized by a zero-order hold. Therefore, a feedforward controller cannot be obtained based on the inverse system;this is because it becomes unstable. Herein, an exact linearization method for a continuous-time system with a pulse-width modulation-type (PWM-type) input has been proposed showing that unstable zeros of the linearized discrete-time system can be moved to the stable region by altering the pulse-centers location. This enables the construction of a stable feedforward controller that achieves an output perfect tracking control. However, the current paper shows a trade-off between the stability of the stabilized zero and the maximum pulse-width. This prevents the unstable zero from moving to a high stability region, and shows some oscillation at the output of the feedforward controller. To address this, a zero-phase error filter has been introduced to reduce the oscillation. Further, a nonlinear deadbeat controller is also proposed, which can be applied to second and higher order systems. The effectiveness of the proposed methods are presented in this paper by performing simulations. Copyright (C) 2020 The Authors.

关键词： pulse-width modulation Perfect tracking control Discrete-time unstable zeros Feedforward control

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Impact of Dead-band Time on the Harmonic Spectrum of Power Converters

Impact of Dead-band Time on the Harmonic Spectrum of Power C...

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IEEE Electric Power and Energy Conference (EPEC)

作者： Patel, Jigneshkumar Sood, Vijay K. Ontario Tech Univ Dept Elect Comp & Software Engn Oshawa ON Canada

ISBN: (纸本)9781728164892

Power electronic (PE) converters suffer from a topological disadvantage as they often employ two series-connected switches within a common leg of a converter. These two switches have a complementary role i.e. when one switch is ON, the other must be OFF otherwise a short circuit will result with impending risks for the switches and power supply. This condition must be respected at all times - during steady-state and transient switching periods. Although modern PE switches are very fast switching, their speed is not infinite. And, in practice, a suitable dead-band time is required with any pulse width modulation (PWM) technique to prevent the occurrence of a short circuit between two switches in a common leg. A larger dead-band time enhances the security of operation of the switches (converter) but at the expense of additional harmonics and lower efficiency. This paper investigates the impact of dead-band time on the harmonic spectrum for a single-phase H-bridge converter for low/medium voltage applications and cascaded H-bridge (CHB) multilevel converter for medium/high voltage applications.

关键词： pulse-width modulation dead-band cascaded H-bridge converter Harmonic evaluation.

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Experimental Harmonics Analysis of UPS (Uninterrupted Power Supply) System and Mitigation Using Single-Phase Half-Bridge HAPF (Hybrid Active Power Filter) Based on Novel Fuzzy Logic Current Controller (FLCC) for Reference Current Extraction (RCE)

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ADVANCES IN FUZZY SYSTEMS 2022年第0期2022卷

作者： Kumar, Mahendar Uqaili, M. A. Memon, Z. A. Das, Bhagwan Mehran Univ Engn & Technol Dept Elect Engn Jamshoro Pakistan Quaid Eawam Univ Engn Sci & Technol Dept Elect Engn Nawabshah Sindh Pakistan

UPS Uninterruptible power supply) is used as backup when the input source, usually the national grid, fails to give power to a load. In addition to the growing use of electronic power devices in industrial and residential systems, such as UPS, controlled rectifiers, SMPS (Switch Mode Power Supplies), and DC Converters, there is a serious problem caused by harmonics in AC mains, which lowers the power quality. Harmonics can cause a variety of problems, including sensitive equipment failure, resonance issues, heated wires, power loss, and inefficient distribution systems. A passive or active power filter could be used to reduce harmonics. However, passive filters are more difficult to design and are bulkier. With the advancement of power electronics, active power filters were developed, and the best combination of both was supplied in the form of hybrid active power filters (HAPF). This study shows an approach to minimizing the harmonics contained in the output of a UPS connected to a nonlinear load. Experiments with several UPS types have been conducted under various nonlinear loads, as well as charging and discharging of batteries, and the proposed technique significantly reduces harmonics in a system with a HAPFs (hybrid active power filter) based on a unique FLCC (fuzzy logic current controller). In this paper, we use a fuzzy logic controller to generate pulse width modulation (PWM) switching signals in a single-phase half-bridge HAPF. The operation of the proposed PWM-FLCC will be studied in a steady and transient state. Based on a connection between the uninterrupted power supply (UPS) supplying a single-phase power to a nonlinear load, different power filter topologies and a brief review of reference current extraction (RCE) methods used in this study were also included and the most common configurations have been compared with their advantages and disadvantages to ensure the right selection of the power filter for UPS connected with the nonlinear load. The res

关键词： Uninterrupted power supply pulse-width modulation Harmonic analysis Power conditioner Harmonic

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FPGA BASED DIGITAL MAGNETIC FIELD DETECTION SYSTEM

FPGA BASED DIGITAL MAGNETIC FIELD DETECTION SYSTEM

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IEEE International Geoscience and Remote Sensing Symposium (IGARSS)

作者： Fan, Hua Yang, Jingxuan Zhang, Jia Zhang, Ke Xing, Dezhi Feng, Quanyuan Univ Elect Sci & Technol China Sch Elect Sci & Engn Chengdu 610054 Peoples R China Shanghai Anl Info Technol Co Ltd Shanghai 201203 Peoples R China Chengdu HiWafer Semicond Co Ltd Chengdu 610299 Peoples R China Chongqing United Microelect Ctr Chongqing Peoples R China Southwest Jiaotong Univ Sch Informat Sci & Technol Chengdu 611756 Peoples R China

ISBN: (纸本)9781728163741

This paper presents a digital magnetic field detection system, which can collect and analyze the remote sensing data by using the analog-to-digital converters (ADCs). The proposed digital magnetic field detection system contains two different types of digital pulse-width modulation (PWM) ADCs by using the complementary metal-oxide-semiconductor (C-MOS) mixed-signal technology and the field-programmable gate array platform (FPGA). The 12-bit digital PWM delta-sigma (Delta Sigma) ADC is implemented in 180nm CMOS mixed-signal technology and achieves the signal-to-noise-distortion ratio (SNDR), the spurious free dynamic range (SFDR) and the effective number of bits (ENOB) are 70.68dB, 92.62dB and 11.44-bit with a supply voltage of 1.2V and at a sampling rate of 58.82kS/s. The digital PWM successive approximation register (SAR) ADC is based on FPGA to reduce the interference in the workpiece magnetic field to enhance reliability. Proposed digital PWM ADCs can be combined with a Hall effect sensor to measure the magnitude of a magnetic field without using the microcontroller, which are widely used for proximity sensing, positioning, speed detection, and current sensing applications.

关键词： Hall sensor digital analog-to-digital convert pulse-width modulation

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Analysis of Symmetric and Asymmetric CHB-MLI Using MC based SPWM and THI-PWM

Analysis of Symmetric and Asymmetric CHB-MLI Using MC based ...

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IEEE Electric Power and Energy Conference (EPEC)

作者： Patel, Jigneshkumar Sood, Vijay K. Ontario Tech Univ Dept Elect Comp & Software Engn Oshawa ON Canada

ISBN: (纸本)9781728164892

Cascaded multilevel inverter (CHB-MLI) has the advantages of modularity and flexibility to generate any number of output voltage levels. It can be configured as a symmetrical or asymmetrical type. The CHB-MLI can be controlled with various modulation techniques, like multi-carrier PWM (MC-PWM), selective harmonics elimination PWM (SHE-PWM), and space vector PWM (SV-PWM). Among these PWM methods, MC-PWM is very well accepted for CHB-MLI topology. This paper investigates, using Matlab simulation, the performance of symmetric and asymmetric CHB-MLI incorporated with MC-PWM techniques, such as phase-shifted PWM (PS-PWM) and level-shifted PWM (LS-PWM). All MC-PWM methods are constructed using sinusoidal and third harmonic injected reference signals.

关键词： pulse-width modulation Cascaded H-bridge inverter Harmonics

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Microprocessor Control System for a Three-Phase Voltage Inverter with a Modified Algorithm 8th

Microprocessor Control System for a Three-Phase Voltage Inve...

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8th International Scientific Siberian Transport Forum (TransSiberia)

作者： Gulyaev, Alexander Ten, Evgenii Fokin, Dmitry Hohlin, Andrei Far Eastern State Transport Univ Seryshev St 47 Khabarovsk 680021 Russia

ISBN: (纸本)9783030379162;9783030379155

In this paper investigates the influence of high frequency switching of power transistors of an autonomous voltage inverter on the distortion of the output quasi-sinusoidal signal. To solve the discovered problem, a modified autonomous voltage control algorithm is proposed, based on the use of different pulse-width modulation frequencies in one half cycle. The standard two-level sinusoidal pulse-width modulation is formed as a result of the intersection of the modulating sinusoid with the reference sawtooth signal. In classical pulse-width modulation, the ratio of the frequency of the reference signal to the modulated frequency is always constant and equal to an integer, i.e., this pulse-width modulation is synchronous. An algorithmic solution is proposed for the formation of a modified sinusoidal pulse-width modulation, when the frequency of the reference sawtooth signal during one period of the modulated sinusoid changes twice from a smaller value to a larger one and vice versa.

关键词： Induction motor Three-phase inverter pulse-width modulation Power losses Microcontroller Frequency converter

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Calculation and Analysis of Dynamic Properties of a Soft Switching Converter under Operation on the Arc Load 40

Calculation and Analysis of Dynamic Properties of a Soft Swi...

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IEEE 40th International Conference on Electronics and Nanotechnology (ELNANO)

作者： Vereshchago, Eugen Kostiuchenko, Vitalii Hrieshnov, Andrii Admiral Makarov Natl Univ Shipbldg NUOS Dept Marine Instrument Mykolaiv Ukraine Admiral Makarov Natl Univ Shipbldg NUOS Dept Marine Elect Power Syst Mykolaiv Ukraine

ISBN: (纸本)9781728197135

The processes in the converter with soft switching transistors operating on an arc load are investigated. A comparative analysis of the calculated frequency characteristics of a PWM converter in normal operation with the characteristics of its linear model is presented. The features of calculating the equivalent frequency characteristics of the loop gain of switching devices are considered. The dynamic resistance of a switching power supply is estimated.

关键词： switching power supply frequency characteristics switching at zero voltage pulse-width modulation chaotic modes

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