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Design, Modeling, and Validation of a High-Speed Rotary pulse-width-modulation On/Off Hydraulic Valve

JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME 2012年第6期134卷 61002-61002页

作者： Tu, Haink C. Rannow, Michael B. Wang, Meng Li, Perry Y. Chase, Thomas R. Van de Ven, James D. Univ Minnesota Dept Mech Engn Ctr Compact & Efficient Fluid Power Minneapolis MN 55455 USA

Efficient high-speed on/off valves are an enabling technology for applying digital control techniques such as pulse-width-modulation (PWM) to hydraulic systems. Virtually variable displacement pumps (VVDPs) are one application where variable displacement functionality is attained using a fixed-displacement pump paired with an on/off valve and an accumulator. High-speed valves increase system bandwidth and reduce output pressure ripple by enabling higher switching frequencies. In addition to fast switching, on/off valves should also have small pressure drop and low actuation power to be effective in these applications. In this paper, a new unidirectional rotary valve designed for PWM is proposed. The valve is unique in utilizing the hydraulic fluid flowing through it as a power source for rotation. An unoptimized prototype capable of high flow rate (40 lpm), high speed (2.8 ms transition time at 100 Hz PWM frequency), and low pressure drop (0.62 MPa), while consuming little actuation power (< 0.5% full power or 30 W, scavenged from fluid stream), has been constructed and experimentally validated. This paper describes the valve design, analyzes its performance and losses, and develops mathematical models that can be used for design and simulation. The models are validated using experimental data from a proof-of-concept prototype. The valve efficiency is quantified and suggestions for improving the efficiency in future valves are provided. [DOI: 10.1115/1.4006621]

关键词： HIGH-speed machining pulse-width modulation HYDRAULIC machinery -- Design & construction VALVES PRESSURE drop (Fluid dynamics) BANDwidthS DESIGN & construction

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Robust Voltage Tracking Control of Three-Phase Four-Wire Split DC Bus Inverter via Time-Scale Separation Technique

Robust Voltage Tracking Control of Three-Phase Four-Wire Spl...

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International Scientific-Technical Conference on Actual Problems of Electronics Instrument Engineering

作者： Valery D. Yurkevich Gennagy S. Zinoviev Novosibirsk State Technical University Novosibirsk Russia

The problem of controller design is investigated for a three-phase four-wire split dc bus inverter with output filters and loads. The proposed time-scale separation technique for controller design gives the possibility to achieve a high accuracy of three-phase voltage generation subject to variations of source voltages or load resistors. The discussed approach to problem of three-phase inverter controller design provides high power quality with small harmonic distortion. The efficiency of the discussed design methodology is highlighted by simulation results.

关键词： Power systems Three-phase inverters pulse-width modulation PID control Time-scale separation method Singular perturbations

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Survey on high-frequency models of PWM electric drives for shaft voltage and bearing current analysis

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IET ELECTRICAL SYSTEMS IN TRANSPORTATION 2017年第3期7卷 179-189页

作者： Asefi, Mahdi Nazarzadeh, Jalal Shahed Univ Fac Engn Tehran Iran

In this study, a review on high-frequency modelling in electric machines is conducted. pulse-width modulation (PWM) creates common-mode-voltage (CMV) and common-mode-current (CMC) in electric drives with high-frequency impacts such as shaft voltage and bearing current which in turn cause bearing failures. To predict and reduce these failures in an electric machine, transitional modelling of high-frequency pulses is necessary. At the first step, several methods for high-frequency modelling in an electric drive are categorised. At the second step, several types of bearing currents discussed and CMV and CMC in electric drives are introduced. At the third step, CMV, CMC and bearing currents are simulated for six types of PWM methods and experimental verification is reported. Finally, root-mean-square value of a distorted parasitic current is introduced for comparing the electromagnetic effects of PWM methods.

关键词： PWM invertors machine bearings electric machines electric drives failure analysis machine theory high-frequency models PWM electric drives shaft voltage bearing current analysis electric machines pulse-width modulation common-mode-voltage CMV common-mode-current CMC electric drives bearing failures transitional modelling high-frequency pulses root-mean-square value distorted parasitic current electromagnetic effects PWM inverters

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Performance Comparison of Tri-level Switching AMB Power Amplifiers Based on Different Current Sensors and Control Methods 1st

Performance Comparison of Tri-level Switching AMB Power Ampl...

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International Symposium on Software Reliability, Industrial Safety, Cyber Security and Physical Protection of Nuclear Power Plant

作者： Zhang, Kai Xu, Yang Dong, Jin-Ping Tsinghua Univ Dept Engn Phys Beijing 100084 Peoples R China

ISBN: (纸本)9789811033612;9789811033605

Active magnetic bearings are advanced bearing components for High Temperature Gas-cooled Reactors. As an important part of active magnetic bearings, switching power amplifiers are designed to accurately convert a command signal to a real bearing coil current. Current ripples of the power amplifiers can be reduced effectively based on different tri-level control methods. Their performances are different. Even when the same control method is used, the performances of amplifiers using electrical circuits with different hardware components are different. To reduce current ripples of amplifiers, the performance of amplifier circuits with different current sensors and different control methods were studied. With the same control method, three kinds of current sensors were used in a power amplifier and their performances were compared. It was shown that hardware delay caused the performance difference. With the same current sensor, a tri-level Sampling-Hold method and a pulse-width modulation (PWM) method were used to control the same amplifier driver. The accuracy of the tri-level PWM amplifier was better. The reason for the performance difference between the two methods was discussed. The experimental results were provided.

关键词： High temperature gas-cooled reactor pulse-width modulation Power amplifier active magnetic bearing

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The Digital Power Amplifier for the Wireless Infrastructure: Status and Prospects

The Digital Power Amplifier for the Wireless Infrastructure:...

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IEEE Topical Conference on RF/Microwave Power Amplifiers for Radio and Wireless Applications (PAWR)

作者： Wentzel, Andreas Huehn, Florian Heinrich, Wolfgang Leibniz Inst Hochstfrequenztech FBH Ferdinand Braun Inst D-12489 Berlin Germany

ISBN: (纸本)9781509034581

In digital power amplifiers the analog signal is not handled directly but encoded in a pulse train. It is restored only at the output by a bandpass filter. Due to the discretization in amplitude, this principle, often referred to as class S, allows for efficient and versatile amplifiers. While in widespread use for audio frequencies, digital PAs have been introduced at microwave frequencies only a few years ago. The paper reviews the state of the art of such PAs for applications in the wireless infrastructure. The key factors determining transmitter performance are addressed and recent results are presented.

关键词： Microwaves power amplifiers class S pulse-width modulation bandpass-delta-sigma modulation

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Control System Design of a Battery Discharge Unit for Space Applications 43

Control System Design of a Battery Discharge Unit for Space ...

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43rd Annual Conference of the IEEE-Industrial-Electronics-Society (IECON)

作者： Yurkevich, Valery D. Makarov, Denis V. Korobkov, Dmitriy V. Kharitonov, Sergey A. NSTU Novosibirsk Russia

ISBN: (纸本)9781538611272

The problem of control system design is discussed for a high frequency DC-DC converter which is based on the push-pull circuit with autotransformer. The proposed converter may be used as a battery discharge unit in power supply system of satellites. The mathematical model of the converter is described. The proportional-integral (PI) current controller and PI voltage controller are designed based on singular perturbation technique. Procedure for selection of controller parameters is highlighted. Numerical simulations are included in order to show the applicability of the proposed design methodology in practice.

关键词： battery discharge unit DC-DC converters pulse-width modulation PI controller singular perturbation method

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Design and Implementation of Isolated Multi-Output DC-DC Power Supply with Fixed and Programmable Voltage Levels 3

Design and Implementation of Isolated Multi-Output DC-DC Pow...

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International Conference on Current Trends in Computer, Electrical, Electronics and Communication (CTCEEC)

作者： Kasar, Nikhil N. Sansare, Vaibhav A. Gaikwad, Asha GHRIET Dept Elect Engn Pune Maharashtra India

ISBN: (纸本)9781538632437

Currently, most of the day-to-day electrical and electronic appliances require DC inputs of different voltage levels. Therefore, to use them in a DC micro-grid, DC-DC converters with multiple voltage levels are required. Standardization in DC micro-grid is not yet done. Hence, every micro-grid has to use specially designed converters. Switched mode power supplies, now-a-days, are having high efficiency (70-80%), small size and light weight. Hence, these switching regulators arc replacing the conventional linear regulators in many applications. In early days, the control circuitry is made up of discrete transistor stages or controlling the duty cycle of switching transistors. Now, control circuitry consisting integrated circuit and microcontrollers. This paper presents the design of isolated multi-output DC-DC power supply where input is taken from batteries or ultra-capacitors. Multiple voltage levels are obtained by designing the multi-winding transformer and further converting them into DC. Fixed output voltage levels are obtained as 5 V and 20 V, while programmable output voltage level is designed (50 V-I40 V) by using DC-DC boost converter controlled with PI controller. This power supply is designed and simulated in MATLAB Simulink.

关键词： Boost converter Multi-winding Transformer Isolation PI controller pulse-width modulation

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A New PWM Shoot-through Control For Voltage-Fed Quasi-Z-Source DC/DC Converters 39

A New PWM Shoot-through Control For Voltage-Fed Quasi-Z-Sour...

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IEEE International Telecommunications Energy Conference (INTELEC)

作者： Kafle, Yuba Raj Hasan, Saad Ul Kashif, Muhammad Hossain, Jahangir Town, Graham E. Macquarie Univ Dept Engn N Ryde NSW 2109 Australia

ISBN: (纸本)9781538610190

This paper presents a new shootthrough control method applicable for an impedance source galvanically isolated DC/DC converter. In impedance source converters, the introduction of shootthrough states increases the switching speed of Hbridge switches about two to three times the switching frequency. This approach reduces the switching transient of all switches of inverters by commutating them once in a switching cycle. The shootthrough states are generated by alternatively switching the single leg of the inverter whereas, in baseline modulation approach, all the switches are turned on during shootthrough states. This method decreases the switching loss of frontend converters and independent controllability of active and shoot through states. This modulation technique is applied and validated to a voltagefeed QuasiZ source isolated DCDC converter with a voltage doubling rectifier.

关键词： DC-DC converters pulse-width modulation quasi-z-source shoot-through modulation

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Low Switching Loss and Harmonics PWM for Three-phase Grid-connected PV Inverter 3

Low Switching Loss and Harmonics PWM for Three-phase Grid-co...

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3rd IEEE International Future Energy Electronics Conference / Energy Conversion Congress and Exposition (ECCE) Asia

作者： Chen, Keng-Yuan Chen, Zheng Xie, Yu-Lin Mao, Xing-kui Yuan Ze Univ Elect Engn Taoyuan Taiwan Fuzhou Univ Elect Engn & Automat Fuzhou Fujian Peoples R China

ISBN: (纸本)9781509051571

Photovoltaic (PV) power generation has become viable alternative due to the advantages of no fuel cost and abundance of sunlight. In a grid-connected PV inverter system, besides stability and reliability, the efficiency is always an important factor. To generate active power effectively, the gridside current must be in phase with the grid voltage. Further, the current harmonics must be low enough to avoid excessive losses. At the inverter side, the efficiency is inverse proportional to the summation of switching loss and conducting loss. Further, for the switching frequency higher than several Kilo-Hz, the dominant loss is switching loss. This means that to have high efficient gridconnected PV power generation system, a low switching loss switching strategy for inverter to produce low harmonics currents is essential. In this paper, a fixed injection PWM is proposed to achieve both low current harmonics and low switching losses. The proposed method can be directly applied to the three-phase two-level grid-connected inverters without any circuit modification. In the simulation, a 30.8% reduction in the current total harmonics distortion is obtained comparing with the conventional switching strategy. Further the 14.78% improvement of inverter efficiency is achieved.

关键词： pulse-width modulation grid-tied inverter

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The Control of the Traction Asynchronous Electric Drive of the Miner Electric Locomotive with Dual-mode Supply

The Control of the Traction Asynchronous Electric Drive of t...

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International Conference on Modern Electrical and Energy Systems (MEES)

作者： Shokarov, Dmytro Zachepa, Iurii Zachepa, Nataliia Chorna, Viktoria Susyk, Dmytro Natl Tech Univ Kharkiv Polytech Inst Kharkov Ukraine Kremenchuk Mykhailo Ostrohradskyi Natl Univ Kremenchuk Ukraine

ISBN: (纸本)9781538617502

The article gives the analysis of the power converter structure and offers the ways of its management for power supply of the traction asynchronous electric drive of a miner contact and accumulator electric locomotive according to the "autonomous source of voltage - the asynchronous engine" scheme which provides a possibility of implementation of various laws of management providing operability of the power converter at various levels of supply voltage. The quality indicators of output tension at various ways of its formation are investigated.

关键词： electric drive asynchronous motor voltage source inverter pulse-width modulation

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