Search

Amongst the various topologies of multi-input multi-output (MIMO) DC-DC converters, single-inductor MIMO (SI-MIMO) converters have the advantages of a reduced component count, a simpler structure, and low cost. These converters are suitable in electric vehicle (EV) applications involving variable ports, essential for performing different functions. Digital control in SI-MIMO converters is promising for enhancing transient performance due to its numerous benefits. However, delays in digital control, particularly computational and pulse width modulation (PWM) delays, can negatively impact the performance of DC-DC converters. Multi-sampling and double PWM update methods can mitigate these control delays, but they often necessitate complex control schemes, adding computational burden. In this work, an advanced multi-sampling PWM technique, integrating sample shift and multi-sampling, is proposed while employing a simple digital PID control scheme. The proposed method was tested for a shared-switch SI-MIMO converter with battery discharging and charging modes in the MATLAB/Simulink environment and compared with the conventional single- and multi-sampling PWM methods. The results demonstrated that the proposed method significantly improved the converter performance, surpassing the conventional single- and multi-sampling PWM methods. In the battery discharging mode, utilizing the proposed method, the output voltage achieved a settling time of 0.075 s in response to a step change in its reference, significantly outperforming multi-sampling, which yielded a settling time of 0.124 s, and single sampling, which exhibited an even longer settling time of 0.898 s. It also demonstrated a minimal overshoot of 0.06 volts compared to 1.5 volts with multi-sampling during the step change in the input voltage. Similarly, in the battery charging mode, upon a step change in the reference output voltage, the proposed method effectively minimized the overshoot of the output voltage to 0.845 volts compared to 1.175 volts with multi-sampling, and it decreased the inductor current settling time to 0.296 s from 0.330 s recorded under multi-sampling. These findings underscore the potential of the proposed method in enhancing the digital control performance of SI-MIMO DC-DC converters in electric vehicles. [ABSTRACT FROM AUTHOR]

What is the role of digital media in contentious politics? On the one hand, digital media plays a central role in informing the public and organizing political movements. On the other hand, it has become a valuable tool for digital repression in authoritarian states. This study concentrates on the patterns of digital media use by pro-government actors in times of nationwide protests in autocracies. It analyzes how pro-government actors establish control over political discourse and information flow online compared to pro-opposition and neutral actors. I argue that, following the increased use of social media by opposition actors during social movements, the state will seek to establish its presence online, attempt to reach larger audiences, and endeavor to frame political issues in a beneficial light to reinforce political control. I use the cases of the 2020–21 protests in Belarus and the 2022 anti-war protests in Russia and employ text-as-data computational methods to analyze communication patterns on public Telegram channels. The results show that pro-government channels in Belarus and Russia followed the protest paradigm and framed protests as illegal, unauthorized activities that cause chaos and disorder. The pro-opposition Telegram channels in Belarus reached a larger audience than pro-state or neutral channels. In contrast, pro-government and neutral channels in Russia dominated the Telegramsphere. These contrasting patterns of Telegram channel activity and popularity suggest that the Russian pro-government online actors are more sophisticated in controlling and manipulating the communication space than Belarusian pro-state actors. [ABSTRACT FROM AUTHOR]

Currently, mistblowers are the most common sprayer type used for pesticide application in orchards. However, maximizing canopy deposition with high application efficiency remained a challenge due to the intricate canopy structure. This study compares the performance of two air-conveyor sprayers on pear trees: a conventional sprayer and an optimized sprayer. The optimized sprayer was equipped with a spray controller that displays its operational conditions (forward speed, spraying pressure, etc.) during application through a user interface of the device. In addition, the controller was capable of recommending spray volume for an orchard with the operator's inputs based on the Tree Row Volume (TRV) method. Two experimental blocks in two pear orchards, with different tree sizes referred to as 'small trees' and 'large trees', were designated to evaluate the foliage deposition and off-target losses of the two sprayers. The conventional sprayer applied a spray volume of 1160 L ha-1 on both orchards following the farmers' conventional procedure. In contrast, the spray volumes of the optimized sprayer were determined by the controller based on the TRV model, resulting in a reduction of 29% and 55% for the large and small pear trees, respectively. The foliar deposition of each block was sampled from five randomly selected trees in a central row, with leaves collected from nine different canopy positions for small trees and twelve positions for large trees. Petri dishes were placed on the ground to assess the ground losses. Poles with nylon threads were mounted at various positions to evaluate airborne drift. The results showed that the mean normalized foliar depositions of the optimized sprayer were 1.57 and 1.81 µg cm-2 / kg-1 tracer ha-1 for large and small trees, respectively, whereas with the conventional sprayer, the depositions were 0.85 and 2.11 µg cm-2 / kg-1 tracer ha-1 for large and small trees, respectively. The optimized sprayer achieved a more uniform deposition distribution throughout the canopy compared to the conventional sprayer, as no significant differences in foliage deposition were detected between positions with the optimized sprayer. The optimized sprayer was capable of providing higher normalized deposits than the conventional sprayer for the large trees with less application volume. In addition, the optimized sprayer reduced spray losses in the air by 10% and 64% compared to the conventional sprayer for small and large trees, respectively, whereas ground losses were diminished by 45% and 50%, respectively. The results of this study suggest that controlling sprayer parameters, along with the spray volume adjustment based on canopy characteristics, may increase foliar deposition and could reduce pesticide use, although its influences on off-target loss reduction were insignificant. [ABSTRACT FROM AUTHOR]

The classical 1.5 μ m band frequency-stabilized laser using acetylene gas saturated absorption can achieve high frequency stability and reproducibility, but its system design is complex and bulky. For some practical applications, a simple, compact system containing anti-interference abilities is preferred. In this study, a low-cost and simple-structured 1.5 μ m frequency-stabilized laser is constructed using digital control methods, wavelength modulation technology, and acetylene gas absorption. The fiber input and output optical devices of the system significantly simplify the optical path and reduce the volume of the system. The error signal is obtained by the first-order differential method, and a combination of the high-speed comparator circuit and the microcontroller unit (MCU) is used to detect the error signal. Through the feedback control method of coarse temperature adjustment and fine current adjustment, the second-level frequency stability of the laser is stabilized within 100 kHz, that is, the frequency stability reaches 10 ​ − 10 . The designed system achieved continuous and stable operation for more than 6 h, and the long-term frequency stability reached 10 ​ − 9 . [ABSTRACT FROM AUTHOR]

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper is about the development and demonstration of a motor drive for e-transport applications based on an innovative hybrid Si-SiC dual switching frequency interleaved buck–boost Y-inverter and a single-rotor Halbach machine. In particular, the focus is the implementation of the required discontinuous inverter modulation scheme, input voltage feed-forward and motor currents feedback control loops, as well as over-voltage, over-current, and over-temperature protections, using an off-the-shelf commercial hardware platform enabling straightforward Simulink-environment programming of all parts, while ensuring the high switching frequency capability required by wide-band-gap semiconductors. Experimental results showed good inverter efficiency, transient dynamic response to load changes, input voltage regulation, and fully functional protection capability, validating the proposed approach as a powerful option for reducing system development time and cost. [ABSTRACT FROM AUTHOR]

This paper focuses on the digital closed-loop design for a step-up converter with hybrid switching. For this purpose, for the first time, the control-to-output small-signal transfer function of a hybrid switching converter is determined in the rational form. Based on it, a type 3 analog controller is designed, and then, its digitized counterpart is found, and the digital controller is designed using a digital signal processor. The closed-loop operation is then validated both through simulation and practical implementation. [ABSTRACT FROM AUTHOR]

This paper proposes a computationally efficient modulated model predictive current control method for a three-phase neutral-point clamped (NPC) central inverter in the photovoltaic energy system. The proposed control method produces optimal triangular region consisting of optimal voltage vectors through an optimization function analysis. The optimal voltage vectors along with their duty cycles are used in the modulation stage to accomplish constant switching frequency operation, low steady-state errors and fast transient response. The control method accomplishes the system requirements such as the maximum power point tracking, balancing of the DC-link capacitor voltages, grid reactive power control, and grid synchronization. The proposed method is evaluated with a MATLAB/Simulink simulation on an 817 kW system under steady-state and varying solar irradiance conditions. The experimental validation is accomplished with a dSPACE MicroLabBox for a 5 kW system to validate the simulation results.

Digital linear slope control (DLSC) method is proposed to attenuate the undershoot and overshoot of the output voltage of a boost converter during the load transient without sensing current. The proposed DLSC method adjusts the slope of the control signal to improve the load transient response. DLSC requires the information of output voltage only and is realized by adding only a few lines of extra program code to the conventional VMC. A mathematical analysis is performed to demonstrate the viability of the DLSC method, and the corresponding algorithms are introduced. A 10 V-15 V, 100-W boost converter operating at 100-kHz switching frequency was built and experimented to validate the effectiveness of the DLSC technique.

Repetitive controller provides a very low third harmonic dimension in the quantities under control. It exhibits an inherent issue when operated to track variable frequency references. The article deals with the analysis of the operating conditions when the controller is executed at variable frequency without any resynchronization with respect to the pulsewidth modulation carrier, which is the most common mode of operation. The delays introduced are then evaluated analytically concerning the sampling and output frequency that must be tracked. The proposed analysis allows obtaining the maximum delay affecting the control chain, which was introduced by the repetitive control desynched operation. The knowledge of the delay introduced in the control loops is at the basis of any control tuning procedure and gains selection, even when adaptive control strategies are used.

This article introduces a research method aimed at achieving optimal control timing for the zero-voltage quasi-square wave switch (ZVS-QSW) in a silicon carbide buck converter across a wide range. The method establishes the correlation function between optimal control timing parameters and load current through composite segmented curve fitting to the plane of the ZVS-QSW state over the entire operating range. It also compensates for the charge change on the filter capacitor to determine the load current at the corresponding operating point. By collecting the input/output voltages and load currents and substituting them into the correlation function, the optimal timing parameters for achieving ZVS-QSW can be determined online. The proposed method is validated on a silicon carbide buck converter prototype with an input voltage of 400 V. ZVS-QSW can be achieved in the conversion ratio range of 0.1-0.9. Consequently, the proposed method not only reduces the difficulty of inductance current measurement but also simplifies and visualizes the timing control of the converter.

This paper presents, switched-LC hybrid converters for versatile power supply with single DC and multiple AC outputs. The proposed converters are two types i.e., 1) parallel and 2) series switched-LC hybrid multi-output converters (SLCHMOC $_{\mathrm {S}}$ ). The parallel-series SLCHMOCS offer multiple 3-phase AC and single-boost DC outputs simultaneously in a single stage. Parallel SLCHMOCS provide $n$ AC outputs with variable voltage and diverse load currents, alongside single boost DC. However, series SLCHMOCS is capable of giving ${n}$ number of AC outputs with the same load current and different voltages. To operate the proposed converters, a hybrid sinusoidal pulse width modulation with constant frequency shoot-through is used. In this work, the proposed converters are implemented for two units operating in a closed loop, supplying one DC and two AC outputs simultaneously at different voltage/current levels. As the proposed converters are capable of delivering multiple AC and single boost DC outputs, they can be applied to the hybrid microgrids. The converters’ steady-state, dynamic and efficiency analyses explain their behaviour. Experimental results validate their performance.

Background: This work presents the design and experimental data results of a functional rotating machine prototype supported by active magnetic bearings (AMBs), whose digital data acquisition and control system were entirely designed using a digital signal processing (DSP) microcontroller and other low-cost electronic components. Situating the case: From studies on rotordynamics, AMBs, and control engineering, a computer code devoted to the design of AMBs was implemented. Methodology: Subsequently, the characterization of the electronic components with the potential of application to the development and integration of the submodules of the control electronic system was carried out. Then, the three-dimensional mechanical design was performed to get the manufacturing plans and to allow for the rotordynamic analysis. Then, the design of the analog power control signal processing submodule was performed, as required to develop the digital-to-analog converter–serial peripheral interface (DAC-SPI) submodule (hardware and firmware) due to the limitation of the number of DAC outputs available on the microcontroller unit (MCU) with DSP features. About the case: Experimental tests were performed with the rotor system based on the proportional–integral–derivative (PID) control parameters calculated in the numerical/computational model implemented in the MATLAB®/Simulink environment. The obtained results demonstrated that the AMB was able to support the shaft operating at two different rotation speeds, namely 1500 and 1800 RPM. Under these conditions, the maximum vibration amplitude of the shaft reached 450 µm and 300 µm, respectively. Additionally, it was demonstrated that the design and construction of a functional rotating machine supported by AMBs using low-cost electronic hardware are feasible and constitute the main contribution of the present paper. The detailed discussion on the design of the associated hardware and firmware can be also considered as an important contribution of the present contribution. [ABSTRACT FROM AUTHOR]

This paper discusses the potential to decrease the response time of a DC–DC converter through the substitution of Si transistors with GaN transistors and the implementation of digital control techniques. This paper introduces an improved methodology for designing digital voltage controllers by analyzing discretization delays and subsequently implementing a modified analog controller design method. The theoretical analysis was verified using an experimental prototype of a 100 W 48 V to 12 V GaN-based DC–DC converter. A digital controller that allows a 50 kHz bandwidth to be achieved based on an STM32G4 microcontroller was developed, and the design of the controller is discussed in detail. The converter was operated with a 500 kHz switching frequency using a 6 µH inductor and a 20 µF ceramic capacitor output filter. Although the digital control introduced a 1.2 µs delay, a converter response time equal to 40 µs was achieved. Simulation models were created and their results were verified via comparisons with experimental results obtained with an AP310 frequency response analyzer. [ABSTRACT FROM AUTHOR]

This paper aims at validating and performance testing of the real-time models for Direct Current (DC) motor-drive systems using Controller-Hardware-in-the-Loop (C-HIL) platform. The DC motor-drive systems are modeled in real-time using STM32F4 Discovery kits, where a minimum time-step of 10 μs is achieved. The closed-loop control scheme is based on adjusting the angular velocity of the DC motor by controlling the armature current, which in turn, controls the developed electromechanical torque of the DC motor. Implementation and performance verification of DC motor-drive systems and the controller can be time-consuming and expensive. The main objective of this paper is to demonstrate the practicality of realtime implementation and performance verification of DC motor-drive systems using the C-HIL testing platform to show perfect concordance with the machine theory without the need for costly commercial real-time simulators. [ABSTRACT FROM AUTHOR]

The digital balancing of the Furuta pendulum is studied when the time delay related to the digital control and the dynamics of the actuator have essential effects on stability. Such cases occur when the sampling rate of the digital control is low, that is, the control cycles are slow due to complex signal processing strategies and/or the implementation of cheap low-capacity microprocessors. A corresponding difficulty is that no direct velocity measurement is available. Critical sampling times are identified and stability charts are constructed and validated by experiments including the possible existence of quasi-periodic self-excited oscillations. [ABSTRACT FROM AUTHOR]

Nowadays, electric vehicles have gained significant attention as a promising solution to the environmental concerns associated with traditional combustion engine vehicles. With the increasing demand for high-performance hypercars, the need for advanced torque control strategies has become paramount. Field-Oriented Control using Current Vector Control represents a consolidated solution to implement torque control. However, this kind of control must take into account the DC link voltage variation and the variation of motor parameters depending on the magnets' temperature while providing the maximum torque production for specific inverter current and voltage limitations. Multidimensional lookup tables are needed to provide a robust torque control from zero speed up to maximum speed under deep flux-weakening operation. Therefore, this article aims to explore the application of FOC 4D control in electrical hypercars and its impact on enhancing their overall performance and control stability. The article will delve into the principles underlying FOC 4D control and its advantages, challenges, and potential solutions to optimize the operation of electric hypercars. An electric powertrain model has been developed in the Simulink environment with the Simscape tool using a S-function block for the implementation of digital control in C-code. High-power electric motor electromagnetic parameters, derived from a Finite Element Method magnetic model, have been used in the simulation. The 4D LUTs have been computed from the motor flux maps and implemented in C-code in the S-function. The choice of FOC 4D control has been validated in the main load points of a hypercar application and compared to the conventional FOC. The final part of the research underlines the benefits of the FOC 4D on reliability, critical in motorsport applications. [ABSTRACT FROM AUTHOR]

A totem-pole bridgeless boost converter is one of the most promising topologies for the power factor correction (PFC) stage in high-power applications due to its high efficiency and small number of components. However, due to the totem-pole structure of the field-effect transistor (FET), very high switching loss occurs via the reverse recovery current of the body diode. To solve these problems, critical mode (CRM) control is a good solution to achieve the valley switching technique. With valley switching of CRM control, the switching loss decreases drastically with decreasing turn-on voltage. But, although the CRM control enables valley switching, it is hard to make an exact valley switching control with general zero-voltage detection circuits. In addition, when a frequency limitation scheme is applied to prevent a very high frequency, the switch can operate with hard switching at the boundary of the frequency limitation. Furthermore, the CRM boost PFC has a low PF and high total harmonic distortion (THD) under light-load conditions due to the large negative current resulting from resonance between the inductor and parasitic capacitance. It becomes worse at near-zero input voltage since the resonance current becomes larger near zero-input voltage. Therefore, in this paper, a totem-pole bridgeless boost PFC converter with high efficiency, high PF, and low THD is developed using TMS320F28377 by Texas Instruments. Based on the basic digital structure of the totem-pole bridgeless converter, the proposed controls help with exact valley switching, PF and THD improvement, and frequency limitation. The prototype converter is verified using 90–264 VAC input voltages and 450 V/3.3 kW output specifications. [ABSTRACT FROM AUTHOR]

In this paper, the results carried out about a study over the possibilities of the Predictive Functional Control (PFC) are presented. The French professor Jacques Richalet and his collaborators developed the PFC. The results presented were obtained, when PFC is applied to industrial processes with complex dynamics such as high order, integral effects in the direct step that make the process asymptotically unstable in open loop and the undesirable phenomena of delay and inverse response. The main objective of the study is to demonstrate the potential offered by the PFC algorithm, in its simplestform, for the control of such processes. To this end, a methodology for synthesizing the PFC controller is developed based on the postulates and principles proposed by the precursors of the method, applied to several real case studies. In all cases, completely satisfactory results were obtained by means of simulation in Simulink-MatLab and finally the results of applying the method to the temperature control of the TCLab minilaboratory developed at the University of Utah are compared. This verifies the real possibilities of the FPC as a prominent alternative to control of real process. [ABSTRACT FROM AUTHOR]

Copyright of Ciencia e Ingenieria Neogranadina is the property of Ciencia e Ingenieria Neogranadina and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents a novel real-time control and electronic instrumentation system (RTC\andEIS) for a prototype plant that uses activated sludge for wastewater treatment. The main contribution in this research was oriented to work on an experimental design with small dimensions and low cost. This design was carried out using two continuous flow storage tanks in which an identification process was carried out with the MATLAB system identification toolbox to know a mathematical model. The mathematical representation obtained is presented as a continuous and a discrete transfer function. To evaluate the performance of the temperature control and instrumentation system, we implemented a simulation of the closed-loop control system and then implemented it using a DAQ, LabVIEW software, electronic devices and the wastewater treatment plant prototype to compare both results. Finally, the secondary treatment effluent was analyzed in a certified water laboratory to have a detailed analysis compared to the initial influent.

Abstract Model Predictive Control (MPC) and Direct Power Control (DPC) are widely used in Doubly Fed Induction Generator (DFIG) applications. However, in the context of DPC‐based MPC for DFIG, there has been a lack of literature focusing on the design of the MPC parameters. In this way, this article introduces a novel technique for designing weighing matrices in Direct Power Model Predictive Control using the Fake Algebraic Riccati Equation (FARE). As FARE is associated with the infinite receding horizon, a small receding horizon can be designed without compromising the robustness. Furthermore, this article presents a computationally efficient linear state‐space model for DPC that, when combined with a small receding horizon FARE design, offers a controller with low computational cost and robustness. The proposed theory is validated through experimental results under normal operation, variable speed operation, and parameter variations. Additionally, the proposed controller is compared to other MPC approaches.

Amongst the various topologies of multi-input multi-output (MIMO) DC-DC converters, single-inductor MIMO (SI-MIMO) converters have the advantages of a reduced component count, a simpler structure, and low cost. These converters are suitable in electric vehicle (EV) applications involving variable ports, essential for performing different functions. Digital control in SI-MIMO converters is promising for enhancing transient performance due to its numerous benefits. However, delays in digital control, particularly computational and pulse width modulation (PWM) delays, can negatively impact the performance of DC-DC converters. Multi-sampling and double PWM update methods can mitigate these control delays, but they often necessitate complex control schemes, adding computational burden. In this work, an advanced multi-sampling PWM technique, integrating sample shift and multi-sampling, is proposed while employing a simple digital PID control scheme. The proposed method was tested for a shared-switch SI-MIMO converter with battery discharging and charging modes in the MATLAB/Simulink environment and compared with the conventional single- and multi-sampling PWM methods. The results demonstrated that the proposed method significantly improved the converter performance, surpassing the conventional single- and multi-sampling PWM methods. In the battery discharging mode, utilizing the proposed method, the output voltage achieved a settling time of 0.075 s in response to a step change in its reference, significantly outperforming multi-sampling, which yielded a settling time of 0.124 s, and single sampling, which exhibited an even longer settling time of 0.898 s. It also demonstrated a minimal overshoot of 0.06 volts compared to 1.5 volts with multi-sampling during the step change in the input voltage. Similarly, in the battery charging mode, upon a step change in the reference output voltage, the proposed method effectively minimized the overshoot of the output voltage to 0.845 volts compared to 1.175 volts with multi-sampling, and it decreased the inductor current settling time to 0.296 s from 0.330 s recorded under multi-sampling. These findings underscore the potential of the proposed method in enhancing the digital control performance of SI-MIMO DC-DC converters in electric vehicles.

The Japan Aerospace Exploration Agency has developed a power processing unit for a 6 kW Hall thruster, a candidate for propulsion systems for geostationary satellites. Hall thrusters have a discharge instability of tens of kHz, which may damage thrusters, power processing units, and satellite systems. This paper proposes our system for detecting discharge current amplitudes that exceed the specified limit of the thruster. The discharge current is converted into a voltage by the current sensor and is output to a digital controller through an AD converter. The system's innovation includes a frequency prediction model and a damping correction algorithm, which allow the system to accurately detect the peak amplitude of the discharge current without testing to measure the frequency characters of the Hall thruster. The design of the amplitude detection system considers the frequencies of the ionization oscillation and the switching frequency of the power processing unit. The frequency prediction model estimates the frequency of discharge current oscillations from simple parameters: the output voltage of the discharge power supply and the thruster dimensions. The amplitude of the discharge current is damped slightly by the frequency characteristics of the system, but the algorithm corrects this. The results of the frequency prediction model agreed well with the actual measurements. The predicted value was 13.2 kHz, while the actual measurement was 8–15 kHz. The integration test showed that the amplitude detection system identified 36 peaks exceeding the specified limit of 80% peak-to-peak during a 100 ms segment, although the actual number was 34. This difference is acceptable. The proposed amplitude detection system can accurately count the peaks in the discharge current that exceed specifications. • An amplitude detection system detects discharge current oscillations that exceed the specifications for protecting satellites. • The algorithm and frequency response of the system are designed considering the frequency of ionization oscillations. • The frequency is estimated by a simple model with only the output voltage of the discharge power supply and thruster dimensions. • The system detected the amplitude of the discharge current oscillations with an error of 5.8%. [ABSTRACT FROM AUTHOR]

Design of mobile robots has become an increasingly growing trend in the technology of modern times. They are very attractive engineering systems, not only because of many interesting theoretical aspects concerning kinematics, intelligent behavior and autonomy, but also because of applicability in many human activities. A typical example is the line following robot (LFR). In order for a LFR to function effectively, it must demonstrate excellent line tracking control. This is achieved by having accurate and responsive control algorithms as well as high precision color sensor systems. This paper proposes a system to show that good line tracking performance can be achieved with moderately simple digital control algorithms. The platform used is a differentially driven wheeled robot constructed using the Lego Mindstorms components. The simulation models are presented and analyzed using MATLAB Simulink. The main programming environment is the EV3 Software. [ABSTRACT FROM AUTHOR]

Model Predictive Control (MPC) and Direct Power Control (DPC) are widely used in Doubly Fed Induction Generator (DFIG) applications. However, in the context of DPC‐based MPC for DFIG, there has been a lack of literature focusing on the design of the MPC parameters. In this way, this article introduces a novel technique for designing weighing matrices in Direct Power Model Predictive Control using the Fake Algebraic Riccati Equation (FARE). As FARE is associated with the infinite receding horizon, a small receding horizon can be designed without compromising the robustness. Furthermore, this article presents a computationally efficient linear state‐space model for DPC that, when combined with a small receding horizon FARE design, offers a controller with low computational cost and robustness. The proposed theory is validated through experimental results under normal operation, variable speed operation, and parameter variations. Additionally, the proposed controller is compared to other MPC approaches. [ABSTRACT FROM AUTHOR]

The conventional proportional-gain-feedback link can only obtain the smallest effective damping region (EDR) due to the control delay among all the active damping methods regarding the capacitor current feedback. The digitally controlled system tends to be unstable when the system resonant frequency reaches the critical frequency caused by the grid impedance variation. To weaken the adverse effect on the system caused by the control delay, phase-lead feedback links are applied along the feedback path to provide phase compensation. By taking the simplicity and reliability of the feedback links into account, this paper proposes an alternative to an ideal differentiator, which consists of the Tustin discrete form of 's' and a digital low-pass filter. This proposed method has an identical phase frequency characteristic as an ideal differentiator but a better magnitude frequency characteristic, and its EDR can reach [0, fs/3]. The system stability analysis is conducted under different resonant frequencies, and under the condition of a weak grid, the co-design approach of the active damper and digital controller is presented. Finally, the experimental results are shown to verify the proposed method. [ABSTRACT FROM AUTHOR]

The classical 1.5 μm band frequency-stabilized laser using acetylene gas saturated absorption can achieve high frequency stability and reproducibility, but its system design is complex and bulky. For some practical applications, a simple, compact system containing anti-interference abilities is preferred. In this study, a low-cost and simple-structured 1.5 μm frequency-stabilized laser is constructed using digital control methods, wavelength modulation technology, and acetylene gas absorption. The fiber input and output optical devices of the system significantly simplify the optical path and reduce the volume of the system. The error signal is obtained by the first-order differential method, and a combination of the high-speed comparator circuit and the microcontroller unit (MCU) is used to detect the error signal. Through the feedback control method of coarse temperature adjustment and fine current adjustment, the second-level frequency stability of the laser is stabilized within 100 kHz, that is, the frequency stability reaches 10​−10. The designed system achieved continuous and stable operation for more than 6 h, and the long-term frequency stability reached 10​−9.

In the article, a device for measuring the parameters of the rotational movement of the auger for dewatering solid waste is proposed based on the analysis of signal processing methods and measurement of physical quantities. It can be used in the development of high-performance special vehicles for transporting waste as the main link in the structure of machines for the collection and primary processing of solid waste. The structural scheme of the means and block diagram of the microcontroller control program algorithm for implementation of the device for measuring the parameters of the rotational motion are proposed. The main technical characteristics of the proposed means are given. The results of experimental tests for measuring the parameters of rotational motion are shown. The results of experimental studies, which are given in the work, confirmed the reliability of the measured parameters.

The input current ripple problem of DC/DC converters receives more and more attention recently. To meet the increasingly demanding requirements, the fundamental components of the current ripple are researched and the corresponding current ripple reduction methods are proposed in this paper. On the one hand, due to the imbalance between the input and output power of the whole system when connected to the grid, the 100-Hz bus voltage ripple is induced. If the bus voltage ripple cannot be regulated effectively, the 100-Hz ripple will be reflected in the DC input side. On the other hand, with low pulse-width modulation (PWM) resolution, the quantized error of digital control is accumulated, which causes the quantized input current ripple. The 100-Hz ripple and the quantized ripple are the main input current ripple components. To solve the problems, a small-signal model of the DC/DC converter is built to calculate the input current ripple mathematically. Based on the theoretical analysis, the proportional–integral–differential-resonant (PIDR) control is proposed and high-resolution pulse-width modulation (HRPWM) technology is applied. Finally, a 2-kW bidirectional DC/DC converter prototype is built. According to the experiments, the current ripple is reduced dramatically by 81.5% at full load with the proposed current ripple reduction methods.

In order to demonstrate the performance of an LLC resonant converter with digital control, in this paper, we analyze the operating principles of the full-bridge LLC resonant converter. According to the operating characteristics of the full-bridge LLC resonant converter at different frequency bands, a simulation model was established using MATLAB Simulink software, and simulations were carried out. The digital control system of full-bridge LLC resonant converter was then designed based on the STM32 microcontroller. The simulation and experimental results demonstrated that the LLC resonant main circuit was always operating within the zero voltage switching (ZVS) state of the primary MOSFET and the zero current switching (ZCS) state of the secondary rectifier diode, while soft-switching was achieved in the full load range. The digital control of the full-bridge LLC resonant converter was ideally realized based on STM32. The input disturbance load test result validated the closed-loop concept of the proposed LLC resonant converter. The step response results in both simulation and load tests show that the power supply system has the desired dynamic response characteristics with low overshoot, short rise time and settling time, while the load step response results in both tests showed that the system has a strong anti-interference ability and robustness. [ABSTRACT FROM AUTHOR]

The Buck converter is a commonly used voltage regulator (VR) structure that supplies power to the load devices and responds to load transients. In most of the applications, the VR is controlled by voltage or current mode control, and some nonlinear approaches are used to improve the transient response which brings more complexities to the closed loop design. To achieve a fast transient response without over-regulation under a load step transient, this paper proposes a digital single-cycle regulation (SCCR) controller, which comprised a fast path, a slow path, and a neutralization path. Unlike the conventional PID control, the neutralization path of the SCCR controller is used to offset the excessive energy change in the first cycle after a load step occurs, which makes the inductor current reach its new static condition in a shorter period of time. The mathematical model of the SCCR control is established in this paper and a scanning algorithm is proposed for the design of the compensator parameters. Experimental results are presented to verify the improvement of the transient response when compared to the conventional and nonlinear PID control, the recovery time is decreased by 64.3% and 43% for load step-up and step-down when compared with nonlinear PID control. [ABSTRACT FROM AUTHOR]

Active power filter (APF) can significantly compensate the current harmonics produced by nonlinear loads. To do this feature, harmonic detection beside harmonic generation play vital role. Direct power controller (DPC) has great harmony with instantaneous power compensation (PQ) algorithm as well as ability to eliminate internal current loops. In addition, deadbeat controller (DBC) has high compatibility for digital implementation, superior control performance and fast dynamic response. However, DBC suffers from time delay regarded to control action calculation and digital implementation. In this paper, a new deadbeat-based DPC method is proposed firstly to control and generates the harmonic currents of APF. Several simulations achieved in MATLAB/SIMULINK beside different experimental tests obtained from a DSP-based active power filter are conducted to illustrate and prove the effectiveness and superior performance of the proposed control system. As a result, the THD of grid current decreases from 22% to 3.2% under steady state where dynamic response under with/without compensation validate significant transient response lower than 5ms.

Arc plasma, characterized by its high current density, high energy concentration, and elevated gas enthalpy, is widely utilized in fields such as metallurgy, chemical industry, energy and environmental protection, as well as aerospace. Plasma treatment of solid waste is one of the advanced environmental protection technologies at the international forefront. The rapid development of plasma technology has led to continuous updates and upgrades of arc plasma power sources. This paper provides a comprehensive review of the research progress in arc plasma technology in China, with a particular focus on two key aspects: structure and control methods. The objective is to provide a novel perspective and insights for the international academic community, thereby driving further development in the field of arc plasma power sources. Furthermore, it discusses and analyzes the future development of arc plasma power sources with a focus on achieving higher system reliability, increased power output, environmentally friendly solutions, and intelligent operation.

In weak grids, control performance of power converters is negatively affected by the significantly varied grid impedance, which can easily lead to degradation of anti-harmonic performance, resonances or even system instability. A rapid control performance monitor is therefore proposed in this work to acquire power converters’ actual performance indexes, i.e., the crossover frequency and phase margin. With the measured real-time information, important functions like health management, control parameters design and adaptive control of power systems can be conveniently realized. The monitor is implemented by perturbating the control loop of the power converter under test with a frequency-autotuned small signal, showing satisfying dynamic response and anti-noise performance. Thanks to the 100% digital implementation, the proposed performance monitor requires no extra hardware and no further cost. The detailed design of the monitor, based on small signal models derivation employing an envelope modeling method, is presented in this article. Extensive experiments were carried out to verify the efficacy of the proposed monitor.

Nowadays, electric vehicles have gained significant attention as a promising solution to the environmental concerns associated with traditional combustion engine vehicles. With the increasing demand for high-performance hypercars, the need for advanced torque control strategies has become paramount. Field-Oriented Control using Current Vector Control represents a consolidated solution to implement torque control. However, this kind of control must take into account the DC link voltage variation and the variation of motor parameters depending on the magnets’ temperature while providing the maximum torque production for specific inverter current and voltage limitations. Multidimensional lookup tables are needed to provide a robust torque control from zero speed up to maximum speed under deep flux-weakening operation. Therefore, this article aims to explore the application of FOC 4D control in electrical hypercars and its impact on enhancing their overall performance and control stability. The article will delve into the principles underlying FOC 4D control and its advantages, challenges, and potential solutions to optimize the operation of electric hypercars. An electric powertrain model has been developed in the Simulink environment with the Simscape tool using a S-function block for the implementation of digital control in C-code. High-power electric motor electromagnetic parameters, derived from a Finite Element Method magnetic model, have been used in the simulation. The 4D LUTs have been computed from the motor flux maps and implemented in C-code in the S-function. The choice of FOC 4D control has been validated in the main load points of a hypercar application and compared to the conventional FOC. The final part of the research underlines the benefits of the FOC 4D on reliability, critical in motorsport applications.

A totem-pole bridgeless boost converter is one of the most promising topologies for the power factor correction (PFC) stage in high-power applications due to its high efficiency and small number of components. However, due to the totem-pole structure of the field-effect transistor (FET), very high switching loss occurs via the reverse recovery current of the body diode. To solve these problems, critical mode (CRM) control is a good solution to achieve the valley switching technique. With valley switching of CRM control, the switching loss decreases drastically with decreasing turn-on voltage. But, although the CRM control enables valley switching, it is hard to make an exact valley switching control with general zero-voltage detection circuits. In addition, when a frequency limitation scheme is applied to prevent a very high frequency, the switch can operate with hard switching at the boundary of the frequency limitation. Furthermore, the CRM boost PFC has a low PF and high total harmonic distortion (THD) under light-load conditions due to the large negative current resulting from resonance between the inductor and parasitic capacitance. It becomes worse at near-zero input voltage since the resonance current becomes larger near zero-input voltage. Therefore, in this paper, a totem-pole bridgeless boost PFC converter with high efficiency, high PF, and low THD is developed using TMS320F28377 by Texas Instruments. Based on the basic digital structure of the totem-pole bridgeless converter, the proposed controls help with exact valley switching, PF and THD improvement, and frequency limitation. The prototype converter is verified using 90–264 VAC input voltages and 450 V/3.3 kW output specifications.