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Multi-locus transcranial magnetic stimulation with pulse-width modulation

BRAIN STIMULATION 2025年第3期18卷 948-956页

作者： Sinisalo, Heikki Laine, Mikael Nieminen, Jaakko O. Souza, Victor H. Matsuda, Renan H. Soto, Ana M. Ukharova, Elena Mutanen, Tuomas Rissanen, Ilkka Stenroos, Matti Koponen, Lari M. Ilmoniemi, Risto J. Aalto Univ Sch Sci Dept Neurosci & Biomed Engn Espoo Finland Univ Sao Paulo Fac Philosophy Sci & Letters Ribeirao Preto Dept Phys Ribeirao Preto SP Brazil Aalto Univ Sch Sci AMI Ctr Aalto NeuroImaging Espoo Finland

Background: In transcranial magnetic stimulation (TMS), a pulse of current driven through a coil on the scalp induces an electric field on the cortex, eliciting neuronal activation. Multi-locus TMS (mTMS) uses multiple coils to generate various electric field patterns, enabling electronic control of stimulation location and orientation. However, changing the stimulation target with mTMS can take up to a few seconds when the driving voltages are adjusted for each coil. Objective: To investigate whether multi-coil TMS combined with pulse-width modulation (PWM) in the microsecond scale could be used to overcome the issue of rapid pulse delivery to different cortical targets. Methods: We devised a methodology to generate and drive PWM approximations of given reference pulses. We compared resting motor thresholds (RMTs) and motor evoked potentials (MEPs) between trapezoidal and PWM pulses in several multi-coil targeting scenarios. Results: The cortical electric field of PWM pulses had high temporal complexity, but the pulse types showed no statistically significant differences when stimulating with 2-or 3-coil combinations. With PWM pulses using five coils, the RMT increased by 9 % (p = 0.06), and MEP amplitudes decreased by 20 % with stimulation doses over 120 % RMT (p < 0.05). Conclusions: Motor responses with trapezoidal and PWM pulses were equivalent when using two or three coils concurrently, but some differences were found with five coils. Using PWM with multi-coil TMS device to control the stimulation targets in millisecond-scale is feasible, although more research is needed to understand the neurophysiological effects of increasing coil count.

关键词： Multi-coil TMS pulse-width modulation Waveform Motor cortex stimulation Electric field time course Neuronal depolarization

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Sliding mode pulse-width modulation of five-leg converter for grid-connected permanent magnet synchronous generator wind turbine

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INTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS 2023年第9期51卷 4374-4396页

作者： Bounadja, Mohamed Belmadani, Bachir Univ Hassiba Benbouali Chlef Dept Elect Engn Chlef Algeria Univ Hassiba Benbouali Chlef Dept Elect Engn LGEER Lab Chlef Algeria

This paper presents sliding mode pulse-width modulation (SMPWM) for current-controlled five-leg converter (FLC) in wind energy system. The proposed topology substitutes at once two three-phase converters, classified as back-to-back (BTB), by sharing one leg between the permanent magnet synchronous generator (PMSG) and power grid. To overcome the coupling of the two sides, the control of common leg is introduced. SMPWM methodology is designed using system dynamic model and surface decoupling approach to make system tracking desired references. The reference currents are selected to perform control requirements of PMSG wind turbine. The phase currents are controlled simultaneously during normal operation and in the event of unbalanced grid voltages. Different operating conditions are tested under wind variations including a turbulence component. The main objectives are to achieve balanced and sinusoidal currents, as well as smooth active and reactive powers injected into the grid. Simulation results show that FLC can act as BTB converters and demonstrate the effectiveness of the proposed control scheme.

关键词： five-leg converter grid code permanent magnet synchronous generator pulse-width modulation sliding mode control wind energy

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A Novel 9T1C-SRAM Compute-In-Memory Macro With Count-Less pulse-width modulation Input and ADC-Less Charge-Integration-Count Output

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS 2023年第10期70卷 3944-3953页

作者： Zhang, Kaili Zhang, Deming Song, Mingyang Guo, Zhipeng Wang, You Wang, Chengzhi Zhang, Yue Zeng, Lang Beihang Univ Sch Integrated Circuit Sci & Engn Beijing 100191 Peoples R China Beihang Univ Hefei Innovat Res Inst Hefei 230013 Peoples R China Nanjing Univ Aeronaut & Astronaut Sch Elect & Informat Engn Nanjing 211106 Peoples R China Acad Mil Sci Natl Innovat Inst Def Technol Beijing 100091 Peoples R China

This paper presents a novel compute-in-memory (CIM) macro, which mainly consists of three modules: input generator, 9T1C-SRAM CIM array and charge-integration-count output (CICO) circuit. For the input generator, it can achieve the pulse-width modulation mapping scheme without counts, leading to a small area overhead. For the CIM array, one row-cascade current mirror circuit instead of a bias voltage source is shared by all CIM cells in one row. And in each CIM cell, its multiply result is characterized by the charge on its capacitor. Based on the charge-sharing principle, the accumulated result is represented by the charge (Q(CBL)) on the charge-bit-line (CBL). In this way, the voltage on the CBL is limited regardless of the number of rows of the CIM array, allowing the large-scale CIM array. For the CICO circuit, it is proposed to quantify the Q(CBL) without the ADC, aiming to achieve high area efficiency. With the 14nm FinFET design kit, the design specification of the proposed CIM macro is introduced in detail and its performance is evaluated. Simulation results show that the proposed CIM macro can achieve 4-1370 TOPS/W energy efficiency with IN/W/OUT precision of 6/1/6b and 98.48%/84.56% test accuracy on MNIST and CIFAR-10.

关键词： Compute-in-memory SRAM count-less pulse-width modulation ADC-less charge-integration-count row-cascade current mirror

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Selective Harmonic Elimination pulse-width modulation for Matrix Converter based Solid-State Transformer 10

Selective Harmonic Elimination Pulse-Width Modulation for Ma...

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10th IEEE International Conference on Power Electronics, Drives and Energy Systems (IEEE PEDES)

作者： Joshi, Archit Nath, Shabari Indian Inst Technol Guwahati Dept Elect & Elect Engn Gauhati India

ISBN: (纸本)9781665455664

This paper presents a pulse width modulation (PWM) strategy based on selective harmonic elimination (SHE) for matrix converter based solid-state transformer (SST). The matrix converter based SST is a three-phase single-stage SST with 3X1 (source-side) and 1X3 (load-side) matrix converters and high frequency transformer for galvanic isolation. The SHE based PWM strategy is applied to the source side converter which reduces the filter size, prevents resonance and provides a uniform amplitude high-frequency sinusoidal voltage at the filter output. pulse density modulation (PDM) is applied at the load-side converter which provides the desired low frequency voltage at the load. The formulation of the SHE-PWM for the switched voltage waveform at the source side converter output is presented and results are obtained through simulation in MATLAB/Simulink.

关键词： selective harmonic elimination matrix converter sst pulse-width modulation pulse density modulation

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An Energy-Efficient Time-Domain Analog CMOS BinaryConnect Neural Network Processor Based on a pulse-width modulation Approach

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IEEE ACCESS 2021年 9卷 2644-2654页

作者： Yamaguchi, Masatoshi Iwamoto, Goki Nishimura, Yuta Tamukoh, Hakaru Morie, Takashi Kyushu Inst Technol Grad Sch Life Sci & Syst Engn Kitakyushu Fukuoka 8080196 Japan Kyushu Inst Technol Res Ctr Neuromorph Hardware Kitakyushu Fukuoka 8080196 Japan

This paper proposes a time-domain analog calculations model based on a pulse-width modulation (PWM) approach for neural network calculations including weighted-sum or multiply-and-accumulate calculation and rectified-linear unit operation. We also propose very-large-scale integration (VLSI) circuits to implement the proposed model. Unlike the conventional analog voltage or current mode circuits, our circuits use transient operation in charging/discharging processes to capacitors through resistors. Since the circuits calculate multiple weighted-sums by charging a capacitance, they can be operated with extremely low energy consumption. However, because a relatively long time constant is required to guarantee calculation resolution in the time domain, they have to use very high-resistance devices, on the order of giga-ohms. We designed, fabricated, and tested a proof-of-concept complementary metal-oxide-semiconductor (CMOS) VLSI chip using a 250-nm fabrication technology to verify weighted-sum operation based on the proposed model with binary weights and PWM input signals, which realizes the BinaryConnect model. In the chip, memory cells of static-random-access memory (SRAM) are used for synaptic connection weights. High-resistance operation was realized by using the subthreshold operation region of MOS transistors, unlike in the ordinary in-memory-computing circuits. We evaluated the energy efficiency and temperature characteristics by measurement using the fabricated chip, where the highest energy efficiency for the weighted-sum calculation was 300 TOPS/W (Tera-Operations Per Second per Watt). The effects by a temperature change can be compensated for by adjusting the bias voltage. If state-of-the-art VLSI technology is used to implement the proposed model, an energy efficiency of more than 1,000 TOPS/W will be possible.

关键词： Artificial intelligence hardware AI processor deep neural networks in-memory computing multiply-and-accumulate pulse-width modulation time-domain analog computing weighted sum very large-scale integration (VLSI)

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Study of Behavior of Voltage and Current Spectra of Three-Level Neutral Point Clamped Converter at Selected Harmonic Elimination Programmed pulse Pattern pulse-width modulation

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ENERGIES 2023年第13期16卷 5183-5183页

作者： Maklakov, Aleksandr S. Erdakov, Ivan N. Moscow Polytech Univ Project Act Ctr Sci Act Sect Bolshaya Semyonovskaya St 38 Moscow 107023 Russia South Ural State Univ Inst Engn & Technol Lenin Prospect 76 Chelyabinsk 454080 Russia

The issue of converted voltage distortion by high-power converters at pulse-width modulation (PWM) with a low switching frequency of semiconductor modules is still relevant. Currently, the Programmed pulse Pattern PWM (PPWM) technique is used extensively that allows pre-eliminating the selected harmonics from the converter's voltage and current spectrum or reducing them to meet the voltage quality standard requirements. A review of scientific publications has shown the insufficiency of available studies on defining and estimating the impact of powerful converters with PPWM. The problem of defining the amplitudes of higher harmonics generated by a converter with PPWM, which are the main cause of electronic equipment failures at the common grid connection point, is particularly relevant. This study considers the behavior of the NPC converter voltage and current spectra at PPWM with the selected harmonic elimination (SHE) for three-level (3L) voltage waveforms. The behavior of up to the 50th non-eliminated harmonics in the NPC converter voltage and current spectra is first shown for a modulation factor changing within 0-1.15 at the pitch of 0.01 for six different SHE PPWM: no. 1-5 and 7;no. 2-5, 7, 11, and 13;no. 3-5, 7, 11, 13, 17, and 19;no. 4-5, 7, 11, 13, 17, 19, 23, and 25;no. 5-5, 7, 11, 13, 17, 19, 23, 25;29, and 31;no. 6-5, 7, 11, 13, 17, 19, 23, 25, 29, 31, 35, and 37. The concept proposed herein allows measuring the current consumed amplitudes of NPC converter with SHE PPWM at the low average error of about 6%. The adequacy of the approach used herein to determine the current harmonic amplitudes has been experimentally verified with laboratory equipment. The results are consistent with engineering accuracy. The research work is promising for further study and estimation of the impact of the NPC converter SHE PPWM for more complex multi-pulse grid connection circuits and resonance phenomena.

关键词： power converter technology pulse-width modulation programmed pulse pattern selected harmonic elimination independent voltage inverter

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A pulse width modulation-Based Sliding Mode Controller for Phase-Shifted Full-Bridge Converter With Diodes in Series on the Lagging Leg

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IEEE ACCESS 2024年 12卷 174006-174016页

作者： Li, Changshuo Zhou, Wei Yang, Qunhui Ji, Fuwu Tongji Univ State Key Lab Marine Geol Shanghai 200092 Peoples R China Tongji Univ China Natl Sci Seafloor Observ Project Management Off Shanghai 200092 Peoples R China Tongji Univ Sch Elect & Informat Engn Shanghai 201804 Peoples R China

The typical strategy for the phase-shifted full-bridge (PSFB) converter is to design a linear compensator based on a small-signal model. However, this approach cannot provide a strongly robust output under changing operating conditions or with perturbations in the converter parameters. In this article, a fixed-frequency pulse width modulation (PWM) based full-order sliding mode controller is proposed to improve the performance of a PSFB converter with diodes in series on the lagging leg. Firstly, to facilitate the application of sliding control laws, we construct a simplified equivalent control model by analyzing the phase-shifted modulation and operating waveforms of the converter. Secondly, we derive strict existence conditions for the sliding phases to ensure that the state trajectories fulfill the requirements. Thirdly, the perturbations of both the external and internal variables are considered in the equivalent control function to improve the stability of the controller. Finally, simulation and experimental results verify that the proposed sliding mode controller provides better dynamic regulation performance and robustness than does a linear controller.

关键词： Control systems Switches Robustness Legged locomotion Voltage control Topology pulse width modulation Perturbation methods Capacitors Switching frequency Sliding mode control Phase-shifted full-bridge sliding mode control pulse-width modulation equivalent control law robustness

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SiGe high-frequency pulse-width modulation for low-noise applications

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e-Prime - Advances in Electrical Engineering, Electronics and Energy 2024年 10卷

作者： Suarez, John Associate Professor Department of Electrical Engineering Widener University 1 University Place Chester 19013 PA United States

This paper details the first-known experimental observation of pulse-width modulation at 100 MHz using silicon-germanium HBT technology. By performing pulse-width modulation (PWM) at a higher frequency, undesired harmonic-components—which are interpreted as noise—are likewise raised to higher frequencies. In doing so, the noise generated by the PWM controller can be raised to frequencies at which it is no longer relevant. Noise-free operation is guaranteed below the operating frequency of the PWM controller, so long as the semiconductor technology supports high-frequency waveform generation. Such capability is readily provided by modern silicon-germanium HBT technology. The paper also provides an integrated-circuit design with additional flexibility for the end user, with simulated performance results. © 2024

关键词： HBT circuit design pulse-width modulation PWM waveform generation Quiet motor control SiGe circuit design Variable-speed motor control

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Spray drift characteristics of pulse-width modulation sprays in wind tunnel

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International Journal of Agricultural and Biological Engineering 2022年第4期15卷 7-15页

作者： Longlong Li Liping Chen Ruirui Zhang Qing Tang Tongchuan Yi Boqin Liu Wei Deng Research Center of Intelligent Equipment Beijing Academy of Agricultural and Forestry SciencesBeijing 100097China Qingyuan Smart Agriculture and Rural Research Institute Qingyuan 511500GuangdongChina National Research Center of Intelligent Equipment for Agriculture Beijing Academy of Agricultural and Forestry SciencesBeijing 100097China National Center for International Research on Agricultural Aerial Application Technology Beijing Academy of Agricultural and Forestry SciencesBeijing 100097China Beijing Key Laboratory of Intelligent Equipment Technology for Agriculture Beijing Academy of Agricultural and Forestry SciencesBeijing 100097China College of Mechanical and Electronic Engineering Northwest A&F UniversityYangling 712100ShaanxiChina

pulse-width modulation(PWM)sprays can improve flow accuracy by adjusting duty cycle and frequency signal which accurately controls the relative proportion of opening time of solenoid *** objective of this research was to determine the impacts of PWM duty cycle and frequency on spray drift *** tests were conducted in a wind tunnel with a PWM variable-rate spraying *** airborne drift and sediment drift were determined with tracer method,and the drift potential reduction(DPR)compared with reference condition of 100%duty cycle at vertical profile and horizontal planes were calculated,*** results show that,at a given frequency,droplet size decreases with the increase of duty cycle,the main reason is that the liquid does not reach full pattern development at lower duty *** cycle has a greater impact than the frequency on spray drift,the influence weights of duty cycle on airborne drift and sediment drift were 88.32%and 77.89%,*** a lower PWM frequency,in addition to the droplet size,the spray drift may be affected by the pulsed spray *** the perspective of reducing spray drift,it is recommended that the PWM duty cycle should be set in the range of 20%-70%to reduce the potential drift in PWM *** research provides a pesticide drift reduction scheme for variable spraying technology,which can serve as a theoretical basis for PWM parameter selection.

关键词： nozzle spray drift pulse-width modulation drift potential reduction droplets spectral

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Tunable electromagnetic resonant shunt using pulse-width modulation

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JOURNAL OF SOUND AND VIBRATION 2021年 500卷 116018-116018页

作者： Auleley, Michel Giraud-Audine, Christophe Mahe, Herve Thomas, Olivier HESAM Univ LISPEN Arts & Metiers Inst Technol F-59000 Lille France HESAM Univ Univ Lille L2EP Lab Electrotech & Elect Puissanc Arts & Metiers Inst TechnolCent LilleHEI F-59000 Lille France Valeo Transmiss Ctr Etud Prod Nouveaux Espace Ind Nord Route Poulainville F-80009 Amiens 1 France

This article proposes a novel mean for tuning the natural frequency of an electromagnetic resonant shunt, using a pulse-width modulation (PWM) circuit. It is used to modulate the value of the capacitance of the shunt, and the electrical frequency is shown to be proportional to the command parameter of the PWM, the duty cycle. An easy and efficient strategy to tune the resonant shunt in real time is then proposed, thus obtaining a low powered and always stable vibration control device. The article proposes the theory of PWM, giving a robust method to predict the dynamics of the system. Then, an accurate multi-mode theoretical model of the tunable resonant shunt coupled to an elastic structure is proposed and experimentally validated on an elastic multi-mode structure, in the case of two different control strategies. The first one is a standard resonant shunt with both the electrical frequency and damping optimized to reduce a given resonance peak. The second one is based on a resonant shunt with the electrical damping as low as possible, which creates an antiresonance and a "notch" type mechanical response at the driving frequency. Both strategies are experimentally validated with real time variation and adaptation of the electrical frequency, obtaining an efficient vibration control device, able to reduce by a factor 40 the vibration level. (c) 2021 Elsevier Ltd. All rights reserved.

关键词： Adaptive shunt Tunable shunt Resonant shunt pulse-width modulation Electro-magnetic transduction Analog electronics

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