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International Conference on Power Electronics, Intelligent Control and Energy Systems

作者： Sanjeevi Kumar Padmanaban Mahajan Sagar Bhaskar Pandav Kiran Maroti Frede Blaabjerg Pierluigi Siano Valentin Oleschuk Research & Development Ohm Technologies Chennai India Dept. of Electrical & Electronics Engg. MIT Aurangabad India Center for Reliable Power Electronics (CORPE) Dept. of Energy Technology Aalborg University Denmark Dept. of Industrial Engg. University of Salerno Italy Institute of Power Engg. Academy of Science of Moldova Moldova

ISBN: (纸本)9781467385886

Hextuple-inverter configuration for multilevel nine-phase symmetrical open-winding DC converter is articulated in this work. Power modular unit consists of six classical three-phase voltage source inverters (VSI). Each VSI includes one bi-directional device (MOSFET/IGBT) per each phase and link to two capacitors for neutral connection. A modified single carrier five-level modulation (MSCFM) algorithm is developed and modulates each 2-level VSI as 5level multilevel inverter (MLI). A set of test results is presented, which are observed from the model based developments in numerical simulation software's (Matlab/PLECS). The results always showed good conformity with the developed theoretical background under working conditions. The proposed converter found suited for (low-voltage/high current) electric vehicles, DC tractions and 'More-Electric Aircraft' applications.

关键词： Nine-phase Inverter Symmetrical/ Asymmetrical Inverter Hex-inverter Multilevel Inverters Multiphase Drives Multiple Space Vectors pulse-width modulation

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Raman-pulse-duration effect in gravity gradiometers composed of two atom interferometers

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Physical Review A 2015年第5期92卷 053613-053613页

作者： Cheng-Gang Shao De-Kai Mao Min-Kang Zhou Yu-Jie Tan Le-Le Chen Jun Luo Zhong-Kun Hu []Key Laboratory of Fundamental Physical Quantities Measurement of Ministry of Education School of Physics Huazhong University of Science and Technology Wuhan 430074 People's Republic of China

We investigated the Raman-pulse-duration effect in a gravity gradiometer with two atom interferometers. Since the two atom clouds in the gradiometer experience different gravitational fields, it is hard to compensate for the Doppler shifts of the two clouds simultaneously by chirping the frequency of a common Raman laser. This leads to an appreciable phase shift. The magnitude of the phase shift relative to the differential phase shift of the two interferometers is in an order of τ/T, and cannot be neglected in the precision measurements such as measuring the gravity gradient and the Newtonian gravitational constant.

关键词： pulse-width modulation RESEARCH GRAVIMETERS (Geophysical instruments) ATOM interferometers GRAVITATIONAL fields RAMAN lasers

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Structured scale dependence in the Lyapunov exponent of a Boolean chaotic map

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Physical Review E 2015年第4期91卷 042917-042917页

作者： Seth D. Cohen Miltec Corporation A Ducommun Company 678 Discovery Drive Huntsville Alabama 35806 USA

We report on structures in a scale-dependent Lyapunov exponent of an experimental chaotic map that arise due to discontinuities in the map. The chaos is realized in an autonomous Boolean network, which is constructed using asynchronous logic gates to form a map operator that outputs an unclocked pulse-train of varying widths. The map operator executes pulse-width stretching and folding and the operator's output is fed back to its input to continuously iterate the map. Using a simple model, we show that the structured scale-dependence in the system's Lyapunov exponent is the result of the discrete logic elements in the map operator's stretching function.

关键词： LYAPUNOV exponents BOOLEAN functions (Mathematics) CHAOS theory LOGIC circuits OPERATOR theory pulse-width modulation

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Model Predictive Control for Spacecraft Rendezvous in Elliptical Orbits with On/Off Thrusters ∗

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IFAC-PapersOnLine 2015年第9期48卷 251-256页

作者： Rafael Vazquez Francisco Gavilan Eduardo F. Camacho Departamento de Ingénierie Aeroespacial Departamento de Ingenieria de Sistemas y Automatica Universidad de Sevilla Camino de los Descubrimientos s/n 41092 Sevilla Spain

In previous works, the authors have developed a trajectory planning algorithm for spacecraft rendezvous which computed optimal pulse-width Modulated (PWM) control signals, for circular and eccentric Keplerian orbits. The algorithm is initialized by solving the impulsive problem first and then, using explicit linearization and linear programming, the solution is refined until a (possibly local) optimal value is reached. However, trajectory planning cannot take into account orbital perturbations, disturbances or model errors. To overcome these issues, in this paper we develop a Model Predictive Control (MPC) algorithm based on the open-loop PWM planner and test it for elliptical target orbits with arbitrary eccentricity (using the linear time-varying Tschauner-Hempel model). The MPC is initialized by first solving the open-loop problem with the PWM trajectory planning algorithm. After that, at each time step, our MPC saves time recomputing the trajectory by applying the iterative linearization scheme of the trajectory planning algorithm to the solution obtained in the previous time step. The efficacy of the method is shown in a simulation study where it is compared to MPC computed used an impulsive-only approach.

关键词： Spacecraft autonomy Space robotics pulse-width modulation Trajectory planning Optimal trajectory Linearization

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Exact Linearization of Three-Dimensional LTI Systems with PWM Inputs

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IFAC-PapersOnLine 2015年第18期48卷 267-272页

作者： Masayasu Suzuki Mitsuo Hirata Utsunomiya University 7-1-2 Yoto Utsunomoiya Tochigi 3218585 Japan

For three-dimensional LTI systems with PWM inputs whose eigenvalues are real and distinct, an exact linearization method using static input transformations is proposed. In this method, two rectangular waves are located in each control period, and their rising/falling timings are treated as the control parameters. This paper shows that the image of the nonlinear input map contains the image of a suitable linear map, which means that some input transformations for the linearization exists.

关键词： pulse-width modulation Linearization Input transformation Nonlinearity Geometric analysis

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Control for the Three-Phase Four-Wire Four-Leg APF Based on SVPWM and Average Current Method

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ACTIVE AND PASSIVE ELECTRONIC COMPONENTS 2015年第1期2015卷 1-7页

作者： Li, Xiangshun Lu, Jianghua Wuhan Univ Technol Sch Automat Wuhan 430070 Hubei Peoples R China

A novel control method is proposed for the three-phase four-wire four-leg active power filter (APF) to realize the accurate and real-time compensation of harmonic of power system, which combines space vector pulse width modulation (SVPWM) with triangle modulation strategy. Firstly, the basic principle of the APF is briefly described. Then the harmonic and reactive currents are derived by the instantaneous reactive power theory. Finally simulation and experiment are built to verify the validity and effectiveness of the proposed method. The simulation results show that the response time for compensation is about 0.025 sec and the total harmonic distortion (THD) of the source current of phase A is reduced from 33.38% before compensation to 3.05% with APF.

关键词： ELECTRIC power filters pulse-width modulation SIMULATION methods & models ELECTRIC currents HARMONIC distortion (Physics)

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Asymmetrical modular mutilevel converter (A-MMC) based HVDC system

Asymmetrical modular mutilevel converter (A-MMC) based HVDC ...

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IEEE Energy Conversion Congress and Exposition

作者： K. V. Iyer A. K. Sahoo N. Mohan Dept. of Electr. & Comput. Eng. Univ. of Minnesota Minneapolis MN USA

ISBN: (纸本)9781467371520

Over the past years, modular multilevel converters (MMC) have been widely researched as a preferred option among voltage source converters for HVDC transmission system. The converter presents modularity to generate high number of output voltage levels by simple series connection of modules, resulting in higher reliability and easy failure management/maintenance. Synthesis of near sinusoidal output voltage waveforms by multilevel operation requires pulse-width modulation at relatively lower switching frequencies, resulting in reduced switching losses. In this paper, asymmetrical submodules in the MMC based HVDC system have been investigated. Use of asymmetrical submodules with different capacitor voltages results in lesser number of semiconductor switches for the same number of output voltage levels, thus reducing the overall size of the converter system. The operating principle using different carrier based modulation schemes is discussed in detail. Modified voltage balancing algorithms based on well known sorting algorithm and PI controller have been investigated for their feasibility to asymmetrical-MMC operation. Simulations with preliminary experimental results are presented to validate the proposed converter operation.

关键词： Asymmetrical submodules High voltage direct-current (HVDC) Modular multilevel converter (MMC) pulse-width modulation Voltage balancing algorithm

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Three-Dimensional Hit-to-Kill Guidance Law for Direct Thrust Controlled Interceptor

Three-Dimensional Hit-to-Kill Guidance Law for Direct Thrust...

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第27届中国控制与决策会议

作者： Naigang Cui Feng Yang Changzhu Wei School of Astronautics Harbin Institute of Technology

ISBN: (纸本)9781479970186

A three-dimensional hit-to-kill guidance law is designed for the direct thrust controlled kinetic kill vehicle to against maneuvering near-space hypersonic targets,which is based-on the Smooth Second-Order Sliding Modes(SSOSM) control law and Non-Homogeneous High-Order Sliding Mode Observer(NHHOSMO).The normal velocity of the Line-of-Sight(LOS) is chosen to be sliding variable based-on the principle of zero angular velocity of *** between different channels is realized by regarding the coupling term of sight angular rate,the acceleration component of the maneuvering target to be uncertainties,which will be accurately estimated by the *** feasibility of the guidance law is verified by simulation,where the pulse-width modulation technical is used to implement direct thrust control.

关键词： Non-Homogeneous High-Order Sliding Mode Observer Hit-to-Kill Three-Dimensional Guidance Law pulse-width modulation

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Random Carrier modulation Technique for Dispersing Harmonics

Random Carrier Modulation Technique for Dispersing Harmonics

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International Congress on Image and Signal Processing

作者： Jie Xu Ziling Nie Junjie Zhu Yinfeng Zhang Huayu Li National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering

ISBN: (纸本)9781467390996

In many aspects, harmonics will cause a series of problems such as electromagnetic interference (EMI), mechanical vibration and harsh noise. Especially when the amplitude of harmonics is high, more serious problem will arise. For these reasons, this paper has made an analysis of the theory of random carrier modulation and presented a practical random carrier modulation technique which is applied to the pulse-width modulation (PWM). Random carrier modulation (RCM) has unique superiority in expanding the distribution of harmonic spectrum, which is of great value to dispersing of the electromagnetic harmonics and balancing the energy of harmonics in the whole frequency domain. The validity and feasibility of the random carrier modulation are verified by simulations. Besides, the proposed RCM can be easily extended to harmonic treatment in other fields. In short, what has been studied in this paper will greatly contribute to depressing the unanticipated high amplitude harmonics.

关键词： Harmonics Random carrier modulation pulse-width modulation harmonics pulse width modulation harmonic spectrum

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Interleaving DC/DC Converter-fed Electric Skateboard with power factor corrected charger

Interleaving DC/DC Converter-fed Electric Skateboard with po...

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Annual Conference of the IEEE Industrial Electronics Society

作者： Sean A. Huang Chang-Ming Liaw Jhong-Yan Ni Department of Electrical Engineering National Tsing Hua University Hsinchu Taiwan 30013

ISBN: (纸本)9781479917631

This paper presents the development of an electric skateboard and with a flyback switch-mode rectifier (SMR) based battery charger. An interleaving DC/DC buck converter-fed DC motor is established and used as the propulsion actuator of the skateboard. Thanks to the interleaving approach, the armature current ripple is reduced, and the fault tolerance of power circuit is preserved due to the redundancy provided by paralleled converter cells. In addition, the simple random pulse-width modulation (PWM) control using pseudo random binary sequence (PRBS) signal is applied to randomize the armature current harmonic spectral distribution. For battery charging, a SMR is developed and utilized as a charger for the electric skateboard. By operating this SMR under discontinuous conduction mode (DCM), the inherent power factor correction (PFC) function of AC input is preserved without applying current mode control. Meanwhile, the controllable and well-regulated DC output voltage is obtained for performing the battery charging.

关键词： DC motor battery buck DC/DC converter charger electric skateboard flyback converter interleaving control power factor correction pulse-width modulation random switching switch-mode rectifier

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