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Thermodynamic control of MEMS meteorology pressure sensing element in low-temperature application down to-45°C

IET SCIENCE MEASUREMENT & TECHNOLOGY 2017年第7期11卷 907-913页

作者： Du, Lidong Zhao, Zhan Fang, Zhen Feng, Yu Yan, Jize Chinese Acad Sci Inst Elect State Key Lab Transducer Technol Beijing 100190 Peoples R China Univ Southampton Elect & Comp Sci Nano Grp Southampton SO17 1BJ Hants England Univ Chinese Acad Sci Sch Elect Elect & Commun Engn Beijing 100049 Peoples R China

In this study, the authors present an alternative method for poor accuracy of piezoresistive meteorology pressure sensing in low-temperature environment (down to -45 degrees C) by incorporating external thermodynamic control. In order to use the designed sensor in such a low-temperature environment, the microelectromechanical systems (MEMS) chip itself has to be kept at 50 degrees C, which is the most common used highest working temperature in meteorology field. The heat compensation is achieved by a pulse-width modulation controlled heating resistor based on proportional-integral-derivative algorithm. The precision of thermal control was obtained at 50 +/- 0.5 degrees C during the bench test. The simulation results from COMSOL software are consisted with lumped element model analysis. Under the condition of environmental temperature down to -45 degrees C, system achieved a maximum absolute error within +/- 0.5hPa after pressure calibration.

关键词： meteorology calibration lumped parameter networks compensation thermodynamics pressure sensors microsensors thermodynamic control MEMS meteorology pressure sensing element low-temperature environment microelectromechanical systems chip heat compensation pulse-width modulation proportional-integral-derivative algorithm thermal control COMSOL software lumped element model analysis pressure calibration temperature 50 degC

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CMV reduction for five-level ANPC converter by PS-PWM strategy

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JOURNAL OF ENGINEERING-JOE 2018年第13期2018卷 425-431页

作者： Liu, Feipeng Xu, Lie Wang, Kui Zhou, Peiyi Li, Yongdong Tsinghua Univ Dept Elect Engn State Key Lab Power Syst Beijing Peoples R China

Five-level active neutral point clamped (ANPC) converter has become one of the most attractive topologies in industry applications, especially in the field of the motor drive. A novel common-mode voltage (CMV) reduction strategy for five-level ANPC is presented, which is based on the phase-shifted pulse-width modulation (PS-PWM). A basic PS-PWM method is presented, which can realise the NP voltage and the flying capacitor (FC) voltages balance. Moreover, a general CMV reduction method is summarised. The proposed CMV reduction strategy can minimise the CMV by injecting zero-sequence voltage to the modulation wave and it does not affect the ability of NP voltage and FC voltages balance. The validity of the proposed CMV reduction method based on PS-PWM strategy is verified by simulation.

关键词： power convertors voltage control motor drives PWM power convertors power system control power capacitors pulse-width modulation basic PS-PWM method NP voltage general CMV reduction method zero-sequence voltage FC voltages balance PS-PWM strategy five-level ANPC converter five-level active neutral point attractive topologies industry applications motor drive common-mode voltage reduction strategy

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Optimized Signaling Method for High-Speed Transmission Channels with Higher Order Transfer Function

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MEASUREMENT SCIENCE REVIEW 2017年第4期17卷 178-186页

作者： Sevcik, Bretislav Brancik, Lubomir Kubicek, Michal ABB Sro Technol Ctr Videnska 117 Brno 61900 Czech Republic Brno Univ Technol Fac Elect Engn & Commun Dept Radio Elect Tech 12 Brno 61600 Czech Republic

In this paper, the selected results from testing of optimized CMOS friendly signaling method for high-speed communications over cables and printed circuit boards (PCBs) are presented and discussed. The proposed signaling scheme uses modified concept of pulse width modulated (PWM) signal which enables to better equalize significant channel losses during data high-speed transmission. Thus, the very effective signaling method to overcome losses in transmission channels with higher order transfer function, typical for long cables and multilayer PCBs, is clearly analyzed in the time and frequency domain. Experimental results of the measurements include the performance comparison of conventional PWM scheme and clearly show the great potential of the modified signaling method for use in low power CMOS friendly equalization circuits, commonly considered in modern communication standards as PCI-Express, SATA or in Multi-gigabit SerDes interconnects.

关键词： High-speed signaling equalization pulse-width modulation signal integrity channel loss multi-gigabit

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A 5 Gb/s Voltage-Mode Transmitter Using Adaptive Time-Based De-Emphasis

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS 2017年第4期64卷 959-968页

作者： Su, Wun-Jian Liu, Shen-Iuan Natl Taiwan Univ Grad Inst Elect Engn Taipei Taiwan Natl Taiwan Univ Dept Elect Engn Taipei Taiwan

A 5-Gb/s voltage-mode (VM) transmitter using adaptive time-based de-emphasis is presented. The duty cycle of the pulse-width modulation data is adjusted by the spectrum-balancing technique. This adaptive VM transmitter does not need an auxiliary cable. It can adaptively compensate the loss of the channels with different lengths. This transmitter and a receiver are fabricated in a 40-nm CMOS process. The active areas of the transmitter and the receiver are 0.075 mm(2) and 0.105 mm(2), respectively. For a 1.1 V supply voltage, the power of the transmitter is 9.3 mW and the total power of the transceiver is 17.5 mW. For a 5-Gb/s PRBS of 27-1 passing through a 9-m coaxial cable with a 15.35-dB loss, the measured root-mean- square and peak-to-peak jitters of the recovered data are 12.25 and 64.44 ps, respectively. The settling time for adaptive time-based de-emphasis is 2.048 mu s. The measured bit error rate is less than 10(-12).

关键词： Adaptive de-emphasis inter-symbol interference pulse-width modulation voltage-mode transmitter

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Series Compensator Based on Cascaded Transformers Coupled With Three-Phase Bridge Converters

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IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS 2017年第2期53卷 1271-1279页

作者： de Almeida Carlos, Gregory Arthur Jacobina, Cursino Brandao Univ Fed Campina Grande Dept Elect Engn BR-58429900 Campina Grande PB Brazil Fed Inst Alagoas IFAL Dept Control & Ind Proc BR-57608180 Palmeira Dos Indios AL Brazil

This paper proposes a multilevel series compensator (MSC) to deal with voltage sags/swells, harmonic compensation, or reactive power compensation. Such a device can be considered as a dynamic voltage restorer or a series active power filter (Series-APF). The MSC can improve the power quality of loads located in stiff systems. The configuration is based on three-phase bridge (TPB) converters connected by means of cascaded single-phase transformers. This arrangement permits the use of a single dc-link. A generalization for K-stages in which K-transformers are coupled with K-TPB converters is presented. The topology permits generating a high number of levels in the voltage waveforms with a low number of power switches in comparison with a classic topology. The multilevel waveforms are generated by the converters through a suitable pulsewidthmodulation (PWM) strategy that takes into consideration the transformer turns ratios. Modularity and simple maintenance make the proposed MSC an attractive solution compared with some conventional configurations. Model, PWM strategy, and overall control are discussed in this paper. Simulation and experimental results are presented as well.

关键词： Cascaded transformers dynamic voltage restorer multilevel series compensator pulse-width modulation series active power filter

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pulse drive: A new power-transmission principle for a compact, high-efficiency, infinitely variable transmission

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MECHANISM AND MACHINE THEORY 2017年 118卷 265-282页

作者： Tsuchiya, Eiji Shamoto, Eiji Toyota Cent Res & Dev Labs Inc 41-1 Yokomichi Nagakute Aichi 4801192 Japan Nagoya Univ Nagoya Aichi Japan

In this paper, a new transmission principle, named "pulse drive," is proposed for potentially realizing a highly compact, high-efficiency, infinitely variable transmission, such as that used in switching electrical power supply systems, by transmitting the driving power intermittently through periodic vibration control. In addition, the experimental results of a prototype pulse-drive transmission are discussed. Conventionally, rotational speed and torque are converted using radius ratios (e.g., gears) or slips (e.g., friction clutches). By contrast, in the proposed principle, this conversion is achieved by controlling the engagement time of compact slipless clutches (e.g., dog clutches). This principle is similar to duty control in electronic voltage converters, which utilize the ratio of engagement time rather than that of turns of coils. The experiments confirmed that the pulse drive can transmit rotational power and that torque can be converted by controlling the engagement time. (C) 2017 The Authors. Published by Elsevier Ltd.

关键词： pulse drive Power transmission Infinitely variable transmission Continuously variable transmission pulse-width modulation

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Passive Loop Filter Assistance for CTSDMs

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS 2017年第10期64卷 1157-1161页

作者： Vercaemer, Dries Raman, Johan Rombouts, Pieter Univ Ghent Dept Elect & Informat Syst B-9000 Ghent Belgium

This brief presents a power reduction technique for continuous time sigma-delta modulators (CTSDMs). The approach consists of two elements. First, a passive low-pass filter is added in front of the modulator's loop filter to reduce the high frequency components in the loop. As a result, the slew rate requirements of the opamps can be greatly reduced which allows a significant power saving. Unfortunately, the insertion of this low-pass filter also changes the modulator's loop gain, and hence affects the noise transfer functions (NTFs) and signal transfer functions (STFs), in an undesired way. Therefore, the second proposed element consists of inserting a compensation branch which is such that the original loop gain, NTF and STF are restored. Thanks to this, our power saving technique is completely transparent on the system level such that all established techniques and toolboxes for CTSDM design can still be used. The technique is especially suited for one-bit CTSDMs, where the amount of high-frequency components in the loop is excessive. To showcase the technique, a self-oscillating sigma-delta modulator (which is a dedicated type of one-bit CTSDM) was implemented in a 65-nm CMOS process. It achieves a peak signal to noise and distortion ratio of 63 dB over a 20-MHz bandwidth at a power consumption of 1.7 mW while occupying a very small chip area of only 0.009 mm(2).

关键词： Analog-to-digital conversion continuous time sigma-delta modulator (CTSDM) low power pulse-width modulation self-oscillating sigma-delta modulator (SOSDM) small area ADC

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OFDM-PWM scheme for visible light communications

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OPTICS COMMUNICATIONS 2017年 385卷 213-218页

作者： Zhang, Tian Ghassemlooy, Zabih Rajbhandari, Sujan Popoola, Wasiu O. Guo, Shuxu Jilin Univ Coll Elect Sci & Engn State Key Lab Integrated Optoelect Changchun 130012 Peoples R China Northumbria Univ Fac Engn & Environm Opt Commun Res Grp Newcastle Upon Tyne NE1 8ST Tyne & Wear England Coventry Univ Sch Comp Elect & Math Coventry W Midlands England Univ Edinburgh Sch Engn Inst Digital Commun Edinburgh EH8 9YL Midlothian Scotland

In this paper, we propose an improved hybrid optical orthogonal frequency division multiplexing (O-OFDM) and pulse-width modulation (PWM) scheme for visible light communications. In this scheme, a bipolar O-OFDM signal is converted into a PWM format where the leading and trailing edges convey the frame synchronization and modulated information, respectively. The proposed scheme is insensitive to the non linearity of the light emitting diode (LED) as LEDs are switched 'on' and 'off' between two points. Therefore, the tight requirement on the high peak-to-average-power-ratio (PAPR) in O-OFDM is no longer a major issue. The simulation and experimental results demonstrate that the proposed scheme offers an improved bit error rate performance compared to the traditional asymmetrically clipped O-OFDM (ACO-OFDM).

关键词： Visible light communications pulse-width modulation Optical orthogonal frequency division multiplexing Peak-to-average-power-ratio

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Model predictive control of distributed generation micro-grids in island and grid connected operation under balanced and unbalanced conditions

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JOURNAL OF RENEWABLE AND SUSTAINABLE ENERGY 2017年第4期9卷 1-17页

作者： Ghanbarian, Mohammad Mehdi Nayeripour, Majid Rajaei, Amir Hosein Jamshidi, Fatemeh Waffenschmidt, Eberhard Islamic Azad Univ Kazerun Branch Dept Elect & Elect Engn Kazerun Iran Shiraz Univ Technol Dept Elect & Elect Engn Shiraz Iran Fasa Univ Dept Elect Engn Fasa Fars Iran Univ Appl Sci CIRE Tech Hsch Koln Cologne Germany

Model Predictive Control (MPC) uses the model of system at current time to predict the system behavior at the future sampling interval in the prediction horizon and sets a number of variables to their references due to their controllability from input variables. This paper concentrates on the design and analysis of a controller for Distributed Generation (DG) microgrids in islanding and grid connected operation modes using a Receding Horizon MPC scheme. In this contribution, active and reactive powers are used in a cost function as an inner control loop to produce switching states. Two outer voltage and frequency droop loops share active and reactive powers between DGs in the microgrid. The design concept of the proposed control system is evaluated through simulation studies and experiment under different test scenarios. The impact of the simulation and the experimental results shows that the operations of the DG units within the microgrid can be coordinated effectively under the proposed control system to ensure stable operation of the overall microgrid and power quality improvement. Published by AIP Publishing.

关键词： MICROGRIDS (Smart power grids) DISTRIBUTED generation of electric power ELECTRIC generators pulse-width modulation ELECTRIC inverters

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MEASUREMENT OF THE THERMAL IMPEDANCE OF LIGHT-EMITTING DIODES AND LIGHT-EMITTING DIODE MATRICES

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MEASUREMENT TECHNIQUES 2017年第1期60卷 46-51页

作者： Smirnov, V. I. Sergeev, V. A. Gavrikov, A. A. Russian Acad Sci Kotelnikov Inst Radio Engn & Elect Ulyanovsk Branch Ulyanovsk Russia Ulyanovsk State Tech Univ Ulyanovsk Russia

A measuring instrument of the frequency and current dependences of the modulus and phase of the thermal impedance of LEDs and LED matrices of 100 W and higher is described. The principle of operation of the measuring instrument is based on the transmission through LEDs of a sequence of impulses of direct current that is pulse-width modulated under the harmonic law, and the determination of the variable component of the temperature of the p-n junction of the LED as the voltage changes during intervals between current impulses. An algorithm is presented to determine the component of full thermal resistance of an LED or an LED matrix from the results of processing the frequency dependences of the modulus and phase of the thermal impedance. Examples of implementation of the algorithm are given.

关键词： LED LED matrix thermal impedance pulse-width modulation harmonic law

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