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Kinetics of narrow-spectrum LED glow under pulsed power

SEMICONDUCTOR PHYSICS QUANTUM ELECTRONICS & OPTOELECTRONICS 2023年第2期26卷 230-235页

作者： Andriichuk, V. A. Nakonechnyi, M. S. Filiuk, Ya. O. Ternopil Ivan Pulyj Natl Tech Univ 46 Mykulynetska str UA-46001 Ternopol Ukraine

The results of experimental investigations of the glow kinetics of narrowspectrum LEDs based on InGaN-GaN 450 and 520 nm and AlGaInP-GaAs 625 nm structures are presented. The increase and decrease of the light flux intensity under pulsed power are described by exponential dependences containing fast and slow components. The time constants of both components decrease with the increase of the pulse frequency for all three types of LED samples. The time constant of the slow component decreases with the increase of the current and voltage pulse amplitudes. The maximum light output on the frequency dependences of LED energy characteristics is observed at the frequency of 75...100 kHz. Further frequency increase results in the decrease of the LED energy efficiency. The obtained results are explained based on the LED equivalent electrical and energy circuits.

关键词： light-emitting diode (LED) pulse-width modulation energy efficiency attenuation coefficient

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Analysis of Walking Cell PWM Strategy in Multilevel Frequency Converter in Fault Condition 9

Analysis of Walking Cell PWM Strategy in Multilevel Frequenc...

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9th International Conference on Modern Power Systems (MPS)

作者： Kazemirova, Yulia Anuchin, Alecksey Zharkov, Alexandr Lashkevich, Maxim Kovyazin, Alexey Savkin, Dmitrii Moscow Power Engn Inst Dept Elect Drives Moscow Russia Perm Natl Res Polytech Univ Tchaikovsky Branch Perm Russia Vector Elect Equipment Plant Votkinsk Russia

ISBN: (纸本)9781665433815

Cascaded multilevel frequency converter contains low-voltage cells in each leg. Bypassing the failed cells ensures the uninterruptable operation of a frequency converter. However, it can lead to a unbalance phase-to-phase voltages. A special control algorithm is required to operate under faulty conditions. Most approaches based on the phase-shift pulsewidth modulation and level-shift pulse-width modulation are considered in this paper. However, these techniques have limitations, such as time delayed operation which limits current loop response time when reference voltage changes and in case of the cell failure. This paper proposes a modulation strategy which solves these problems. It implements pulse-width modulation in a single cell with sequential cell switching and can rapidly adapt to the failure of any cell without impact to the quality of the output voltage. The operation of the proposed pulse-width technique under faulty conditions was verified using Simulink Model.

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

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A Circulating Current Suppression Strategy for MMC Based on the 2N+1 PWM Approach

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WORLD ELECTRIC VEHICLE JOURNAL 2023年第4期14卷 106页

作者： Zhang, Guozheng Song, Jiahui Li, Chen Gu, Xin Tiangong Univ Sch Elect Engn Tianjin 300387 Peoples R China Zhejiang Univ Adv Elect Equipment Innovat Ctr Hangzhou 311107 Peoples R China

Compared with other topologies, the modular multilevel converter (MMC) has the advantages of higher scalability and lower harmonic distortion. When carrier-based pulse-width modulation approaches are used for the MMC, the number of carriers increases for more sub-modules, and the complexity of the control and the memory required increases as a result. In addition, the synchronization of several carriers is another issue. Due to the unique constructional characteristics of the MMC, circulating currents will be generated internally, causing distortions in the arm currents and, thus, unnecessary converter losses. In this paper, an improved 2N+1 pulse-width modulation approach with low control complexity and a circulating current suppression strategy are proposed. Firstly, the conventional carrier phase-shifted 2N+1 pulse-width modulation approach is improved so that the number of carrier signals adopted in each arm is always two. Secondly, the redundant switching states are used to suppress the circulating current. Finally, the effectiveness of the proposed strategy is verified experimentally. The results show that the proposed method reduces the control complexity while retaining the output performance. Meanwhile, the circulating current can be suppressed.

关键词： modular multilevel converter (MMC) pulse-width modulation circulating current

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A Single-Phase Inverter Topology with Seven-Level Output based on T-type Structure 6

A Single-Phase Inverter Topology with Seven-Level Output bas...

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6th International Conference for Convergence in Technology (I2CT)

作者： Sudheer, D. Sai Reddy, Sowmya Kumar, J. Satish Ayyapparaju, Ch B. Reddy, M. Srinivas JNTUK Aditya Engn Coll Elect & Elect Engn Surampalem India JNTUH Malla Reddy Inst Technol Elect & Elect Engn Hyderabad India

ISBN: (纸本)9781728188768

This paper introduces a novel single-phase seven-level inverter structure that is based on a modified T-type structure. This topology employs a reduced number of devices compared to classical multilevel inverter (MLI) topologies. It also uses a single DC source that renders this topology suitable for PV applications. The DC-link capacitors required in this topology have reduced size which in turn reduces the overall cost of the system. The working modes of the circuit and modulation method of the proposed structure are presented comprehensively. Finally, the introduced topology is simulated in the environment of MATLAB/SIMULINK and the obtained output results are presented.

关键词： multilevel inverter T-type structure pulse-width modulation

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A Commutation Optimization Strategy for High Speed Brushless DC Drives with Inaccurate Rotor Position Signals 16

A Commutation Optimization Strategy for High Speed Brushless...

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16th International Conference on Ecological Vehicles and Renewable Energies (EVER)

作者： Wang, Lu Zhu, Z. Q. Bin, Hong Gong, L. M. Univ Sheffield Dept Elect & Elect Engn Sheffield S1 3JD S Yorkshire England Midea Grp Corp Res Ctr Shanghai 201203 Peoples R China

ISBN: (纸本)9781665449021

The control performance of Hall sensor based high speed brushless DC (BLDC) motor drives depends heavily on the accuracy of Hall sensor signals. Due to the existence of Hall signal errors, the system may operate under unbalanced conditions which will lead to asymmetric currents and high torque ripple. For high speed drive, the pulse-width modulation (PWM) update delay will also lead to inaccurate commutation. In this paper, two Hall signal errors, i.e., misaligned and uneven Hall signal errors, are investigated and a Hall signal balancing strategy is developed to detect Hall signal errors and regenerate balanced Hall signals. A new PWM generation scheme is then proposed to eliminate the PWM update delay. Both simulation and experiment results have verified the effectiveness of the proposed strategy.

关键词： Brushless DC (BLDC) drive commutation balancing strategy Hall signal error permanent magnet motor pulse-width modulation

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A Study of Conduction Noise Suppression Control for Two-Motor Drive Systems

A Study of Conduction Noise Suppression Control for Two-Moto...

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Asia-Pacific International Symposium on Electromagnetic Compatibility (APEMC)

作者： Hanioka, Shota Iezawa, Masahiro Ogasawara, Satoshi Mitsubishi Electr Corp Adv Technol R&D Ctr Tokyo Hyogo Japan Hokkaido Univ Grad Sch Informat Sci & Technol Sapporo Hokkaido Japan

ISBN: (纸本)9781728176215

This paper introduces a pulse-width modulation (PWM) method for a two-motor drive system that reduces the propagation of conduction noise to the power supply. This twomotor drive system consists of two motors with each of the two inverters connected to a common DC bus. The proposed method suppresses the common mode voltage ideally to zero by shifting the rise and fall times of the output voltage of each inverter. Our experimental results show that the rise and fall times of the output voltage can be synchronized even when the two inverters are driven at different amplitudes and frequencies. We further confirmed that the proposed method suppresses the propagation of conduction noise to the power supply.

关键词： pulse-width modulation noise suppression control electromagnetic interference common mode voltage

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Online thermal parameter identification for permanent magnet synchronous machines

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IET ELECTRIC POWER APPLICATIONS 2020年第12期14卷 2340-2347页

作者： Xiao, Shuai Griffo, Antonio Univ Sheffield Dept Elect & Elect Engn 3 Solly St Sheffield S Yorkshire England Univ Sheffield Dept Elect & Elect Engn F125 Mappin Bldg Sheffield S Yorkshire England

Temperature monitoring of permanent magnet synchronous machines (PMSMs) is of great importance because high temperatures can significantly shorten the lifetimes of motor components. Accurate temperature predictions can be achieved using reduced-order lumped parameter thermal networks (LPTNs) with accurate thermal parameters. In this study, an online estimation method based on the recursive Kalman filter algorithm is introduced for online identification of the thermal resistances in a three-node LPTN representing motor stator iron, stator winding and permanent magnet. The identification procedure requires a rotor temperature measurement, which is provided by an accurate pulse-width modulation-based estimation method. The proposed methodology is experimentally validated and applied to real-time fault detection of the motor cooling system.

关键词： rotors synchronous motors stators permanent magnet motors temperature measurement Kalman filters lumped parameter networks fault diagnosis cooling power system parameter estimation permanent magnets pulse width modulation reduced order systems iron permanent magnet synchronous machines temperature monitoring motor components reduced-order lumped parameter thermal networks recursive Kalman filter algorithm thermal resistances motor stator iron rotor temperature measurement online thermal parameter identification PMSMs three-node LPTN stator winding pulse-width modulation real-time fault detection motor cooling system Fe

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Common mode noise suppression control for two-motor drive systems

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ELECTRONICS AND COMMUNICATIONS IN JAPAN 2022年第1期105卷

作者： Hanioka, Shota Iezawa, Masahiro Ogasawara, Satoshi Takemoto, Masatsugu Orikawa, Koji Mitsubishi Electr Corp Adv Technol R&D Ctr 8-1-1 Tsukaguchi Honmachi Amagasaki Hyogo 6618661 Japan Hokkaido Univ Fac Informat Sci & Technol Sapporo Hokkaido Japan Okayama Univ Dept Elect & Commun Engn Okayama Japan

This paper introduces a pulse-width modulation (PWM) method for a two-motor drive system that reduces the propagation of conduction noise to the power supply. This two-motor drive system consists of two motors with two inverters, each of which is connected to a common DC bus. The proposed method suppresses the common mode voltage ideally to zero by shifting the rise and fall times of the output voltage of each inverter. Our experimental results show that the rise and fall times of the output voltage can be synchronized even when the two inverters are driven at different amplitudes and frequencies. We confirm that the proposed method suppresses the propagation of conduction noise to the power supply.

关键词： common mode voltage electromagnetic interference noise suppression control pulse-width modulation

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Dynamics of Hydraulic Drive Equipped with Discrete Return Flow Controller 6th

Dynamics of Hydraulic Drive Equipped with Discrete Return Fl...

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6th International Conference on Industrial Engineering, ICIE 2020

作者： Serov, V.A. Ustinov, S.A. Titarenko, V.B. JSC Federal Scientific Production Center "Titan-Barricades" Lenin Avenue Volgograd400071 Russia

ISBN: (纸本)9783030548131

This paper dwells upon the research into the dynamics of a hydraulic drive equipped with a flow controller for the return line of its hydraulic cylinder. This circuit is different from the existing discrete control solutions we know in the sense that its discrete controller is at the return line, making such circuit usable in hydraulic drives that carry co-directional or alternating loads. To assess the dynamic properties of this type of hydraulic drive, the authors built a mathematical model. The simulations in SimInTech produced the curves of speed change and piston rod positioning, pressures, and flow from the cylinder cavities;curves of pressures as the functions of the controller parameters (frequency and duty cycle of PWM). The findings are as follows: the amplitude of pressure fluctuations in the hydraulic cylinder cavities depends on the PWM frequency, as at under 15 Hz (which is close to the self-oscillation frequency of a hydraulic system), this amplitude can reach 100% of the static pressure;at 15–30 Hz, 50%;at ≥50 Hz, it is below 10%;the time it takes the rod to change its speed depends on the PWM frequency. Approaching 50 Hz, the transient becomes ever longer;at >50 Hz, it becomes virtually constant;for a discrete flow controller placed at the outlet, the optimal parameters are PWM frequency of 25–50 Hz and PWM duty cycle of 0–0.5. © 2021, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Discrete controller Energy efficiency Hydraulic drive pulse-width modulation

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Zero-current transition single-ended forward converter

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IET POWER ELECTRONICS 2020年第6期13卷 1227-1235页

作者： Soltanzadeh, Karim Islamic Azad Univ Najafabad Branch Young Researchers & Elite Club Najafabad Iran

In this study, a novel zero-current transition (ZCT) auxiliary circuit is applied to pulse-width modulation single-ended forward converter (PWM SEFC). The proposed ZCT circuit has achieved the power switch zero-current switching (ZCS) turn-on;the power switch ZCT turn-off;the auxiliary switch ZCS and zero-voltage switching turn on/off and soft-switching conditions for output diodes. Moreover, the transformer core reset is prepared by the ZCT circuit and tertiary winding is removed. The novel ZCT-PWM SEFC is analysed at a steady-state for operating under continuous conduction mode. The proposed ZCT circuit is designed, and the experimental result from a 200 W-100 KHz prototype is prepared to confirm the theoretical analysis.

关键词： DC-DC power convertors PWM power convertors resonant power convertors zero current switching zero voltage switching switching convertors switching circuits zero-current transition single-ended forward converter novel zero-current transition auxiliary circuit pulse-width modulation ZCT circuit power switch zero-current switching auxiliary switch ZCS zero-voltage switching turn soft-switching conditions novel ZCT-PWM SEFC frequency 100 0 kHz power 200 0 W

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