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Summary: This paper presents a novel three‐phase hybrid multilevel inverter (TPHMLI) designed for grid‐connected solar photovoltaic (SPV) systems. The TPHMLI combines series‐connected bridge topologies of half and full circuits to generate 11 stages of line load voltages, reducing the need for DC sources. It also introduces an improved pulse width modulation (PWM) approach, addressing computational challenges and high‐frequency triggering issues. Practical validation in a laboratory setting demonstrates the MLI's functionality and effectiveness. Furthermore, the advanced MLI topology successfully addresses design issues in grid‐integrated SPV structures, including power quality, efficiency, and reliability. It excels in managing reactive power and fault obstructive capabilities. Extensive simulations using MATLAB/Simulink confirm its superior performance, making it a promising solution for power conditioning units in grid‐connected solar PV systems. This research contributes to clean and sustainable energy conversion technologies, enhancing power quality and cost‐effectiveness, with significant potential for practical applications in the renewable energy sector. [ABSTRACT FROM AUTHOR]

The paper deals with the dynamics of a resistance spot welding system. At the core of this system is a transformer, which is powered on the primary side by a pulse-width modulated inverter and has a full-wave output rectifier on the secondary side that provides a direct welding current. The entire system is nonlinear, due to magnetic hysteresis and electronics. The electronics prevent the current from flowing in all parts of the welding transformer at separate time intervals during the voltage supply period; therefore, not all the parameters affect the dynamic of currents and voltages all the time so the system is also time-variant. To design a high-performance welding system and to predict the maximum possible welding current at a specific load, it is necessary to know the welding and primary currents. The leakage inductances of the system can reduce the maximum welding current significantly at higher frequencies and the same load. There are several methods to determine these currents, each with its drawbacks. Measurements are time-consuming, using professional software is expensive and requires time to learn and free open-source software has many limitations and does not guarantee the correctness of the results. The article presents a new, fourth option—a theoretical derivation of analytical expressions that facilitate straightforward and rapid calculation of the welding and primary currents of the resistance spot welding system with symmetrical secondary branches. The derivation of the mathematical expressions is based on the equivalent circuits that describe the system in different operating states. The results of the numerical simulations confirmed the derived expressions completely. [ABSTRACT FROM AUTHOR]

The permanent magnet synchronous motor (PMSM) avoids commutation-related torque ripples and produces smooth torque. Its great handling capacity and better efficiency make it an excellent choice for high-demand applications. A typical PM motor drive fed with pulse width-modulated voltages may cause the motor insulation to break down if rapid voltages (dv/dt) occur across the motor terminals. Applying variable voltage with low dv/dt and implementing multiple inverter topology can solve this issue. Multilevel converters have minimal switching losses, better power quality and the ability to operate at both fundamental and higher switching frequencies. In this study, a three phase stacked multilevel inverter-based FOC driven PMSM drive design is proposed. Here, the neutral point is a capacitor intermediate point on DC side, where current is naturally balanced throughout a switching cycle. This makes it possible to use downstream batteries and even lower voltage equipment, greatly increasing efficiency, improved performance and smother control at low speed. Therefore, direct-battery-driven electric vehicles will be able to use this. A 33 level inverter-based PMSM drive was used to implement the FOC, and the simulation results were used to validate it. The Matlab/Simulink tool is used to simulate the entire system. [ABSTRACT FROM AUTHOR]

The permanent magnet synchronous motor (PMSM) avoids commutation-related torque ripples and produces smooth torque. Its great handling capacity and better efficiency make it an excellent choice for high-demand applications. A typical PM motor drive fed with pulse width-modulated voltages may cause the motor insulation to break down if rapid voltages (dv/dt) occur across the motor terminals. Applying variable voltage with low dv/dt and implementing multiple inverter topology can solve this issue. Multilevel converters have minimal switching losses, better power quality and the ability to operate at both fundamental and higher switching frequencies. In this study, a three phase stacked multilevel inverter-based FOC driven PMSM drive design is proposed. Here, the neutral point is a capacitor intermediate point on DC side, where current is naturally balanced throughout a switching cycle. This makes it possible to use downstream batteries and even lower voltage equipment, greatly increasing efficiency, improved performance and smother control at low speed. Therefore, direct-battery-driven electric vehicles will be able to use this. A 33 level inverter-based PMSM drive was used to implement the FOC, and the simulation results were used to validate it. The Matlab/Simulink tool is used to simulate the entire system.

Smart and precision agriculture seeks to boost the efficiency of operations and crop yield by using modern technology. Modern tools such as sensors, imagery cameras, and deep learning enable farmers to identify and control weeds, pests, and diseases in real-time. A robotic platform can carry these modern types of equipment and achieve the mentioned objectives precisely. Automatic and accurate navigation of this autonomous robot in agricultural fields is essential for performing these precision tasks. An agricultural robotic platform was designed and developed for row crop fields. The robot navigation system comprises two main components: a vision-based row detection system for path tracking and a motion controller system. The vision-based guidance system processes acquired image data from a tilted camera in front of the robot to identify the crop row's position. The Hough transform method was used to determine the position of the crop rows. Using the resultant guidance line equations, the motion controller directs the robot to move automatically between rows without harming the crops. Differential speed steering allows both wheels on the robot to rotate at different speeds. The steering system improved the robot position error by controlling both powered wheel speeds. To move the robot among the crop rows, it generates the wheel speed difference command. The robotic platform effectively followed the rows of sugar beets at a velocity of 0.5 m/s, exhibiting an average lateral offset of 12 mm and a standard deviation of 22 mm. [ABSTRACT FROM AUTHOR]

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The paper proposes a novel speed sensor‐less stator flux‐oriented vector control of dual‐stator induction generator suitable for high‐power applications in grid‐tied wind energy conversion system. In this control strategy, the magnitude and angle of the flux are directly estimated by the measured stator voltages and currents. As the voltage and current sensors are placed on the stationery stator part, therefore, the proposed control strategy does not affect the robustness of the machine compared to the conventional rotor flux‐oriented vector control where the sensors need to be mounted on the rotating part of the machine. Moreover, the proposed speed encoder‐less stator flux‐oriented vector control eliminates the use of speed encoder, thereby reducing the cost and eliminating the error caused due to faulty speed measurement by the speed encoder of the overall system. The performance of the novel speed sensor‐less stator flux‐oriented vector control scheme has been verified by simulation and then experimentally on a 2 hp, 415 V, 50 Hz, three‐phase dual‐stator induction generator drive. The control strategy was implemented through dSPACE 1104 DAC card. From the simulated and the experimental results, it is evident that the proposed control strategy reflects improved performance w.r.t. conventional rotor flux‐oriented vector control. [ABSTRACT FROM AUTHOR]

Light emitting diodes (LEDs) play an essential role in lighting, and green earth activities because of their high efficiency, longevity, and reduction of carbon dioxide emissions during illumination. However, the brightness level of LED light sources must be adjusted appropriately for the backlight source or illumination; therefore, pulse amplitude modulation (PWM) is a commonly used method of LED control. This article experimentally investigated human interaction with the visual comfort effect of the light obtained using different PWM frequencies on an object in a sensor-based intelligent lighting system. Critical light frequencies are vital for the eye to distinguish light stimuli according to time. Histograms of the object were created according to the light frequency, and the results are discussed. The eye's response to light frequencies changing over time is important for visual comfort, and examining light frequencies in the range of 25–250 Hz was sufficient to conclude the study. It has been experimentally shown that light frequencies around 160 Hz, and above this value provide visual comfort. [ABSTRACT FROM AUTHOR]

The most recent advancement in switched-capacitor boost inverters for high-frequency ac systems and solar PV utilization is their reduced component count. SC-based multilevel inverters (MLIs) are the ideal solution for PV applications since they have a larger voltage gain and a sensorless mechanism for self-voltage balancing. This article presents a boost inverter scheme for higher-level output that involves input voltage boosting. The proposed topology can be reconfigured to produce 9 and 13 levels of output voltage with alternative topologies and a voltage gain of four or three, respectively. Twelve semiconductor devices, three capacitors, and a single input source are used to achieve the voltage gain/higher levels. The proposed boost topology has been contrasted with a number of related topologies and empirically validated using a number of experimental findings.

In thin‐film transistors (TFTs), issues such as interface states may lead to unstable device performance and complex physical phenomena, such as frequency dispersion effects. This paper establishes a three‐terminal TFT compact model capable of replicating capacitance dispersion phenomena and directly applying to SPICE circuit simulations. The model decomposes the transistor's capacitance frequency response into the superposition of responses from different electronic states. The different electronic states are emulated by parallel branches, each composed of voltage‐dependent capacitance and resistance connected in series. The Powell algorithm is employed to achieve automatic parameter optimization. The model is generic for TFTs and successfully replicates capacitance dispersion phenomena in carbon nanotube (CNT) and indium‐gallium‐zinc‐oxide (IGZO) thin‐film transistors. This work provides insights to the circuit behavior of display driver circuits at high frequencies and improving circuit reliability. [ABSTRACT FROM AUTHOR]

Recently, multiphase drives have emerged as a notable alternative for three-phase drives in several domains, including electric marine propulsion, locomotive traction, and high-power industrial applications where fault tolerance and high reliability are required. This study uses a graphical approach to develop a new carrier-based Pulse-Width Modulation (PWM) that reduces the root-mean-square value of the output current ripple in two-level multiphase inverters with an odd number of phases. The optimization process calculates the optimal common-mode voltage for each switching period. Numerical models and experiments with five- and seven-phase inverters demonstrate the effectiveness of the developed PWM technique, which can reduce the number of commutations while obtaining the lowest output current ripple.

This article presents a 6.78 MHz single-stage wireless power transfer (WPT) receiver (RX) using 0X/1X regulating rectifier with improved voltage mode (VM) delay compensation for implantable medical devices (IMDs). The regulation of 0X/1X modes is achieved through pulse width modulation (PWM), with the frequency set at 1/16 of the carrier clock to ensure circuit stability and enhance power conversion efficiency (PCE) under light loads. VM delay compensation has the advantage of power consumption. However, the traditional VM on-delay compensation may become ineffective because a large voltage pulse will occur on the RX side input when the circuit delays increase. Therefore, an improved VM on-delay compensation method is proposed. Coarse compensation for on-delays can be achieved by reusing the control signal generated from off-delay compensation loop, as off-delay compensation processes will not be influenced by on-delay compensation processes. It allows the on-delay compensation loop to function normally and finely compensate for on-delays. The proposed rectifier is designed in $0.18\mu $ m CMOS process. It can achieve output voltage management of 1.8V. Comparing with other regulating rectifier, the proposed rectifier has a fast transient response of $14~\mu $ s and a small chip area of 0.91 mm2. The simulation results indicate that this rectifier can attain high PCE of 84.6% in light load ( $500\Omega $ ) and peak PCE of 93.5% in heavy load ( $50\Omega $ ). The high voltage conversion ratio (VCR) of over 93% is also achieved under the large circuit delays.

Single-stage differential mode inverters (DMI) have been extensively utilized in three-phase grid-connected systems due to several advantages, such as few semiconductor devices resulting from their simple and modular configuration. Nevertheless, the modulation and control strategy require further enhancement to enable more efficient power conversion across various operations. Therefore, this paper introduces a detailed analytical model of the SEPIC-DMI, leading to the development of a hybrid discontinuous modulation scheme pulse width modulation (DMS-PWM), which incorporates zero voltage switching (ZVS), denoted as Hybrid DMS-ZVS-PWM approach. In the proposed strategy, the duty cycle of SEPIC-DMI is zero for one-third of the grid frequency cycle, which leads to minimizing conduction and switching power losses. Moreover, the voltage stress on the components is significantly reduced due to DMS-PWM. For ZVS, a simplified active-clamp circuit is proposed and designated using a single switch and two small capacitors. The proposed active-clamp circuit is integrated into the SEPIC-DMI to verify SEPIC power switches’ ZVS and zero current switching (ZCS). The ZVS/ZCS improves the inverter efficiency by major minimization in power losses. The mathematical derivations and performance measurements (simulation and experiment) are provided to show the superiority of the proposed hybrid DMS-ZVS-PWM method. The peak efficiency of SEPIC-DMI is enhanced from 90% to 94%, and the voltage stress is curtailed in all components with 13%.

The human intervention free bidirectional efficient energy exchange between the grid and Electric Vehicles (EVs) relies on effective bidirectional power flow control in Wireless Power Transfer (WPT) system. This essential bidirectional control feature enables the grid to charge the EV’s battery and, during surplus energy periods, allows the EV to feed power back to the grid. This capability facilitates the implementation of Vehicle-to-Grid (V2G) functionalities. Implementing this bidirectional flow requires sophisticated modulation techniques to ensure seamless power transfer and optimize overall efficiency. In comparison to pulse width modulation, pulse density modulation (PDM) proves more effective in minimizing switching losses in the converter. PDM efficiently manages the amplitude of high-frequency pulses generated by the inverter and converter systems for WPT applications. However, the PDM techniques are not effectively investigated in the bidirectional wireless power transfer system (BWPT). In this paper, Fuzzy Logic Controlled Pulse Density Modulation (FLC-PDM) approach for the BWPT is proposed for the first time. This approach uses dual side pulse density control for high-frequency converters with the fuzzy rule base to adjust the pulse density and duty ratio based on the load demand. The proposed approach aiming to optimize efficiency across diverse loads and regulate the output voltage and provides effective control approach for the BWPT system. This method ensures constant switching frequency output voltage regulation and delicate shifting operation for high-frequency converter switches, requiring no additional components. The circuit simulations and hardware prototype testing are performed for the 3.7 kW power rating and 85 kHz operating frequency to validate the proposed FLC-PDM approach for the BWPT circuit and yielded an efficiency over 93% across diverse load resistances and pulse densities.

As power demand from electric vehicles and digital loads increases, the use of direct current power supplies is increasing. As a result, the application of microgrid utilizing various distributed power systems is expanding. As demand power and load capacity increase, parallel operation of multiple power converters is required to increase the capacity of power converters used in distributed power systems. Among parallel control methods, load sharing through communication has a significant effect on control performance due to communication speed and reliability. This paper proposes an instantaneous load-sharing parallel control method using a high-speed communication method that can transmit data necessary for load-sharing every control cycle. The proposed communication method uses enhanced PWM and capture communication using a DMA module to compensate for the shortcomings of the existing method using PWM and capture functions. Whenever the master voltage controller is executed, the data required for parallel operation is updated, and by transmitting this data to the slave, instantaneous load sharing control with high speed response is possible. We explain the communication and system architecture of the proposed method and present the communication protocol specifications and design. The performance and validity of the proposed instantaneous load sharing parallel control method were verified through simulation and experiments.

Implementing dimming control in visible light communication (VLC) systems often involves a trade-off that reduces data rates. To address this, we propose a hybrid visible light (VL)/Infrared (IR) communication scheme that leverages pulse amplitude modulation (PAM) symbols in both VL and IR spectra, alternating them within pulse width modulation (PWM) “ON” and “OFF” slots. By efficiently using PWM “OFF” slots, the achievable data rate drop due to dimming is mitigated without affecting illumination. To ensure synchronization during the switch between VL and IR links, we design real-time dimming control state machines at both ends of the link, enhancing link stability. Additionally, we develop an adaptive hybrid frame structure that dynamically adjusts the length of transmitted information as the duty cycle continuously changes, ensuring uninterrupted communication. Experimental results from implementation using field-programmable gate arrays (FPGA) demonstrate real-time transmission under precise full-range dimming control, dynamically ranging from 1 to 0 with a resolution of 0.0053, maintaining a consistent 10 Mb/s data rate at bit error rates (BERs) lower than 3.4 × 10−4 and 20 Mb/s at BERs lower than 7.0 × 10−3 within a link range of 0.53 m without light concentration at the transmitter. Compared to baseline VLC, our system achieves a 100% data rate improvement at a duty cycle of 0.5, and supports stable data transmission even in low-light conditions.

The paper deals with the dynamics of a resistance spot welding system. At the core of this system is a transformer, which is powered on the primary side by a pulse-width modulated inverter and has a full-wave output rectifier on the secondary side that provides a direct welding current. The entire system is nonlinear, due to magnetic hysteresis and electronics. The electronics prevent the current from flowing in all parts of the welding transformer at separate time intervals during the voltage supply period; therefore, not all the parameters affect the dynamic of currents and voltages all the time so the system is also time-variant. To design a high-performance welding system and to predict the maximum possible welding current at a specific load, it is necessary to know the welding and primary currents. The leakage inductances of the system can reduce the maximum welding current significantly at higher frequencies and the same load. There are several methods to determine these currents, each with its drawbacks. Measurements are time-consuming, using professional software is expensive and requires time to learn and free open-source software has many limitations and does not guarantee the correctness of the results. The article presents a new, fourth option—a theoretical derivation of analytical expressions that facilitate straightforward and rapid calculation of the welding and primary currents of the resistance spot welding system with symmetrical secondary branches. The derivation of the mathematical expressions is based on the equivalent circuits that describe the system in different operating states. The results of the numerical simulations confirmed the derived expressions completely.

The comparative performance analysis of conventional PI controller and Fuzzy Logic Controller for a switched mode converter application. Switched mode converters needs to regulate its output voltage to lower voltage and must quickly respond to fast load and line variations or transients to keep the output voltage within a limited range. The design of high performance linear proportional integral controller for switched mode converter presents series of challenges due to nonlinear nature of the plant process. Fuzzy logic controller is mostly used in variety of industrial applications including use in domestic appliances and main tool of operation of fuzzy logic controller is membership function. By using the MATLAB and Simulation we compare the characteristics of the linear proportional integral controller and nonlinear fuzzy logic controller with switched mode converter and also which gives the desired results. The main comparison for Proportional Integral controller (PI) and Fuzzy logic controller (FLC) is to get the pure Direct current (DC) without any fluctuations for sensitive applications. The Switched Mode Converter with both the PI controller and Fuzzy logic controller is implemented and output characteristics are analyzed and compared. The switched mode converters are efficient in power conversion, taking a main voltage AC input and converting it down to a low voltage DC output. AC-DC switched-mode converters are better used. It is used for the external desktop power supply laptop, set-top box, and the wall plug-in charger for smartphones and computers. [ABSTRACT FROM AUTHOR]

To ensure that a variable-rate spray (VRS) system can perform unmanned aerial spray in accordance with a prescription map at different flight speeds, we examine in this paper such significant factors as the response time of the VRS system and the pressure fluctuation of the nozzle during the variable-rate spraying process. The VRS system uses a lag compensation algorithm (LCA) to counteract the droplet deposition position lag caused by the system response delay. In addition, pulse width modulated solenoid valves are used for controlling the flowrates of the nozzles on the variablerate spray system, and a mathematical model was constructed for the spray rate (L min-1) and the relative proportion of time (duty cycle) each solenoid valve is open. The pressure drop and solenoid valve response time at different duty cycles (50~90%) were measured by indoor experiments. Meanwhile, the lag distance (LD), spray accuracy, and droplet deposition characteristics of the VRS system were tested by conducting outdoor experiments at different flight speeds (4m s-1, 5m s-1, 6m s-1). The results show that LCA can effectively reduce the LD. The LD values of the VRS system with LCA ranged from -0.27 to 0.78m with an average value of 0.32m, while without LCA, the LD values increased to 3.5~4.3m with an average value of 3.87m. The overall spray position accuracy was in the range of 91.56~97.32%. Furthermore, the spray coverage and deposition density, determined using water sensitive paper, were used to evaluate the spray application performance taking into account the spray volume applied. The VRS system can provide the most suitable spray volumes for insecticide and fungicide plant protection products. Based on a prescription map, the optimized VRS system can achieve accurate pesticide spraying as well as desirable spray coverage and deposition density. [ABSTRACT FROM AUTHOR]

Due to environmental concerns, electric vehicles (EVs) are becoming more and more common in automobiles. Since electrical vehicles rely on rechargeable batteries to manage their power supply, therefore, it’s important to have a reliable, efficient, and affordable battery charger that can consistently deliver the required output for the specific EV’s battery. A DC-DC converter with a pulse width modulation (PWM) based Sliding-Mode Voltage controller is presented in this paper to help reduce charging time by achieving the required output voltage, high current density, and negligible overshoot for the specified lithium-ion battery system. Both ideal and nonideal conditions are used to analyse the proposed converter. The performance of dc and ac side inductors has been designed and analysed to ensure their efficiency and affordability. According to the findings, the proposed converter is able to maintain a power factor of approximately 90% with less total harmonic distortion both of which are ideal for the high-current density load. [ABSTRACT FROM AUTHOR]

In this paper, the Preisach model for magnetic hysteresis of grain-oriented silicon steel under PWM excitation is improved. First, an improved Preisach model for the magnetic hysteresis of grain-oriented silicon steel under PWM excitation is proposed. Second, the experimental platform for grain-oriented silicon steel sheets under PWM excitation is established. Finally, by comparative analysis, it is concluded that the error of the improved model is far less than that of the classical model (the error here refers to the discrepancy between experimental results and theoretical model predictions). The improved model is 1.4% to 9% more accurate than the classical model. A more accurate model can provide more accurate material parameters for the calculation of the magnetic field in the transformer core, which is of great significance to the production and design of the transformer. [ABSTRACT FROM AUTHOR]

Vibration, in most cases, is an undesirable phenomenon in electro-mechanical systems. The adverse effects of vibration in a system are noise, loss of energy, compromise on comfort, and reduced life span of mechanical systems. The current study focuses on vibration damping of a Flexible Cantilever beam (FCB) by utilizing a differential type of electromagnetic actuator. The electromagnetic forces of both actuators are controlled by Pulse Width Modulation (PWM) using a current controller designed in the lab. The electromagnets are mounted above and below the FCB by maintaining a distance along the same vertical axis. The non-contact active vibration attenuation study is carried out by varying the PWM values of upper and lower electromagnets to produce different electromagnetic forces. The current research work compares different combinations of forces on upper and lower electromagnets experimentally and, based on the analysis, provides the best combination of forces on both actuators to damp the vibrations as swiftly as possible. The study is divided into three cases where case I study the vibration damping with the same PWM on both electromagnets; in case II and case III, one of the electromagnets has fixed PWM while the PWM on other electromagnet is varied. [ABSTRACT FROM AUTHOR]

Traditional current and voltage strategies proposed for the single-phase rectifier with pulse width modulation (PWM) used in the AC charging system for electric vehicles, have a large response time and the percentage of total harmonic distortion (THD) of the line current is more than 2%, which causes a reduction of the power factor (PF). The present paper focuses on the robust sliding mode current–voltage control (SMCVC) design for the single-phase rectifier with PWM. This SMCVC strategy used the grid current directly without any rotating coordinate transformations and reduced the complexity computational of the implementation algorithm and allows to satisfy the following desired performances, low THD of the input current and the PF is around one in a faster response time. In this paper, the proposed control strategy is compared and verified with proportional integral (PI) control and proportional integral sliding mode current control (PI-SMCC) by Matlab/Simulink. At the end of this paper, simulation examples are given to illustrate our approach and to show that our proposed method provides very good results with respect to some literature results. [ABSTRACT FROM AUTHOR]

This paper presents an in-depth exploration of a single-phase multilevel cascaded H5 (CH5) transformerless inverter employing both phase-shifted PWM (PS-PWM) and level-shifted PWM (LS-PWM) methodologies. A comparative analysis is conducted with the conventional multilevel inverter (MLI) topologies, specifically the cascaded H-bridge (CHB) and H5 inverter configurations. The investigation delves into the impact of modulation index variations, load fluctuations, and modulation methods on the inverter's operational performance.While switches in the CHB-MLI operate continuously at the carrier frequency state using PS-PWM and LS-PWM methods, the CH5-MLI exhibits a unique behavior with some switches toggling at high frequency, while others synchronize with the grid frequency. The CH5-MLI topology demonstrates efficiency improvements and a reduction in total harmonic distortion (THD). Notably, employing the LS-PWM method yields more significant efficiency enhancements and THD reduction compared to the PS-PWM method. To analyze power loss characteristics under diverse operating conditions, the PLECS simulation environment is leveraged for calculating conduction and switching losses.The application of phase-shifted and level-shifted carrier-based pulse width modulation strategies to high and low-frequency switching switches results in minimized output harmonics, elevated operator safety, and enhanced overall reliability and efficiency. This work contributes significantly to the field by offering a detailed exploration of the CH5-MLI topology's dynamic behavior, modulation strategies, and their collective impact on performance metrics such as efficiency, THD, and power losses.

Selective harmonic elimination pulse-width modulation (SHE-PWM) method has been widely used in various industrial multilevel converters befitting from low switching frequencies and precise elimination of low-order harmonics. Most of existing studies focus on accelerating calculation of switching angles or optimizing predictive neural networks. However, these offline methods cannot dynamically deal with the errors introduced by nonuniform dc sources of multilevel converters or biased placements of switching angles. This paper proposes an online adaptive SHE (OA-SHE) algorithm to compensate these errors. Errors caused by nonideal dc (NID) sources and leading-lagging placements (LLPs) are analyzed in detail. The error of output waveform is comprehensive result of NID sources and LLPs. By introducing feedback, the output waveform accuracy of multilevel converters can be increased greatly. Realization of the particle swarm optimization (PSO) with an embedded control system is presented to acquire good real-time performance. With the OA-SHE method, the value of particles has been higher than the initial value. High order harmonics, including 1st, 5th, 7th, 11th, and 13th components, are suppressed by the low-pass filter. Comparing to existing studies, this online algorithm does not need detailed model parameters and can be directly applied to practical applications achieving multi-objective optimization. Finally, both simulations and experiments are carried out to verify the effectiveness of this algorithm.

Summary: The modular multilevel converter (MMC) is a novel prospective multilevel converter topology for high‐voltage or high‐power applications. This paper presents the 3‐ Φ model integrated into a linear model in transient analysis and the design of current controller for MMC. This paper analyzes the control interactions of MMC on nearby turbine generator. The eigenvalue analysis is used to evaluate the impact of different controller modes of MMC. The impact of converter control with nonlinear switches is analyzed through the transient simulation. The eigenvalue analysis and controller design are carried out on a linear model, and the transient simulation analysis is performed on both the D‐Q model and a three‐phase model of MMC using MATLAB‐Simulink. The results show that the transient simulation of three‐phase model on the proposed approach is consistent with the transient simulation of D‐Q model. Also, the transient simulation results show a satisfactory response with the current controller parameters of the MMC at various operating cases. To validate the results of MATLAB‐Simulink model, the proposed system is implemented in hardware‐in‐the‐loop (HIL) simulation with an integrated subsystem built in two real‐time simulators. The subsystem of mathematical model is implemented in dSPACE, and the subsystem of 3‐ Φ MMC with controller is implemented in Typhoon. The HIL simulation results show a satisfactory response and consistent with MATLAB‐Simulink model results. [ABSTRACT FROM AUTHOR]

This paper works on the modelling of solar PV with series parallel connection of the strings for the composite climate location and the detailed study has been done on the gate signal of the chopper used for boosting with three different conditions. As the climate conditions are very important factor for the installation of the project to fulfill the captive requirements, a study has also been done with the help of climate consultant software so that the radiations capacity and potential to develop the energy is with in its maximum output capacity. In the next phase an inverter has also been connected for the conversion into single phase AC output for the testing of the model for the usage in the load or grid. Various methods for the control of the booster has been analyzed and considered. Simulation is done on a Matlab software and the result is analyzed. [ABSTRACT FROM AUTHOR]

The development of microcontroller technology has been implemented in the robotics industry, particularly in performing tasks that are risky for living beings, especially humans. In this context, a wheeled smart car robot can automatically extinguish fires. The fire extinguishing system is taken over by the robot's system when fire or heat is detected, and the robot's controller activates the extinguishing system, spraying water at the fire point. The ESP 32 CAM microcontroller serves as the processing and controlling unit, handling data and displaying real-time camera images to ensure accurate fire extinguishing. Additionally, a mecanum wheel drive mechanism is added to enhance the robot's movement flexibility. [ABSTRACT FROM AUTHOR]

The performance of grid-connected wind turbine systems that use a Doubly Fed Induction Generator (DFIG) is explored in this work. In the suggested configuration, two conversion stages are present. In the first step, Alternating Current (AC) voltage is changed into Direct Current (DC) voltage. At this point, the conventional two-level converter is implemented. The second stage involves the conversion of DC to AC using a five-level Modular Multilevel Converter (MMC). Voltage fluctuation is observed in the DC link. It is anticipated that the Fuzzy Logic Control (FLC) approach will be able to adjust the DC link voltage at the MMC of the second stage of conversion. For the purpose of the Pulse Width Modulation (PWM) system, the current controller is accountable for regulating the current signals and the reference signals. As a result, the PI Controller (PIC) is being evaluated for use in this function. Carrier-based Phase Disposition (PD) PWM is employed for MMC switch control. The proposed controllers’ performance is validated in Matlab/Simulink. [ABSTRACT FROM AUTHOR]

Multilevel inverter technology has become the most significant method of energy conversion from DC to AC for uninterrupted power supply. The quality of the power supply depends on the appearance of harmonics, which is considered a problem that needs to be overcome. This paper demonstrates the use of a new modulation technique to reduce the harmonics in both diode-clamped and cascaded multilevel inverters, examining its Total Harmonic Distortion (THD) compared to other PWM methods. Simulations were carried out in MATLAB/Simulink for five-level diode-clamped and cascaded multilevel inverters. The simulation results of both multilevel inverters using the sinusoidal PWM, modified reference PWM, modified carrier PWM, and modified reference and modified carrier PWM methods showed that the latter had the best THD performance for both inverter types, especially for the cascaded multilevel inverter. [ABSTRACT FROM AUTHOR]

To ensure that a variable-rate spray (VRS) system can perform unmanned aerial spray in accordance with a prescription map at different flight speeds, we examine in this paper such significant factors as the response time of the VRS system and the pressure fluctuation of the nozzle during the variable-rate spraying process. The VRS system uses a lag compensation algorithm (LCA) to counteract the droplet deposition position lag caused by the system response delay. In addition, pulse width modulated (PWM) solenoid valves are used for controlling the flowrates of the nozzles on the variable-rate spray system, and a mathematical model was constructed for the spray rate (L min-1) and the relative proportion of time (duty cycle) each solenoid valve is open. The pressure drop and solenoid valve response time at different duty cycles (50%~90%) were measured by indoor experiments. Meanwhile, the lag distance (LD), spray accuracy, and droplet deposition characteristics of the VRS system were tested by conducting outdoor experiments at different flight speeds (4m s-1, 5m s-1, 6m s-1). The results show that LCA can effectively reduce the lag distance. The lag distance (LD) values of the VRS system with LCA ranged from -0.27 to 0.78m with an average value of 0.32m, while without LCA, the LD values increased to 3.5~4.3m with an average value of 3.87m. The overall spray position accuracy was in the range of 91.56%~97.32%. Furthermore, the spray coverage and deposition density, determined using water sensitive paper (WSP), were used to evaluate the spray application performance taking into account the spray volume applied. The VRS system can provide the most suitable spray volumes for insecticide and fungicide plant protection products. Based on a prescription map, the optimized VRS system can achieve accurate pesticide spraying as well as desirable spray coverage and deposition density.

This work presents the design and implementation of a circuit that uses a proportional, integral, and derivative (PID) controller to control the revolutions per minute (RPM) of the direct current (DC) motor in real time that uses a microcontroller platform. The algorithm used in the microcontroller was the algebraic equations of the general PID controller equation. The paper discusses the structure of a PID algorithm and its implementation. From the algebraic equations, the error, cumulative error, and delta error of the PID controller have been found. The designed algorithm is implemented using the Arduino software (IDE). The aim of this work is to control the speed (RPM) of the DC motor using the PID design technique. The designed control system circuit is affordable. The system is tested in real-time, steady-state error, and response time is inspected successfully. The designed circuit is tested for various speed inputs satisfactorily. The speed control using PI and PID control methodology is described.

ABSTRACT: The research paper focuses on the reduction and control of harmonic in a 3-phaseSquirrel Cage induction motor (SCIM) which drive by a pulse width modulation (PWM) controlled three-phase converter using a newly proposed ANN-Grasshopper optimization Shunt Active filters (ANN-GOSAF) method. The converter is a nonlinear load whose operation generates harmonics, posing power quality problems to the system which results in excessive heating and motor torque pulsation. The effect of Total Harmonic Distortion (THD) on a three-phase squirrel induction motor with and without (ANN-GOSAF) was analyzed using MATLAB/Simulink software and compared with other previous methods by other researchers. The vector control method has been applied for improving the three-phase squirrel induction motor's dynamic performance. Also, 3-phase voltage source inverter (VSI) is used for indirect induction motor control speed through the pulse width modulation (PWM). The shunt power active filter (SAPF) is directly connected in parallel with the line. The grasshopper optimization algorithm is applied to perform the optimum data set while the ANN method is applied to minimize the signal error, for optimum shunt active filters PWM pulses generation. The ANN controller is applied for shunt active power filter to regulate voltage DC-link response. Second-order filter and compensator functions are performed by shunt-connected current control-VSI linked through an inductor with a DC tank capacitor and reduction of torque harmonics was performed using Grasshopper Optimizer.The SAPFs were configured and inserted into the model and then tuned to targeted frequencies at such harmonic orders, to produce signals which are out of phase with the harmonics present in the supply signal. The result shows the reduction of current harmonics from 32.28% to 0.75% while the voltage harmonics were correspondingly reduced from 79.50% to 1.87%. This resulted in purer waveforms of both current and voltage of the three-phase induction motor thereby improving motor performance, energy-use efficiency and reduced operating cost.

This article presents the method of implementation and the results of experimental investigations illustrating an influence of parameters of the signal controlling the current flowing through power LEDs on their junction temperature and on parameters characterizing the light emitted by them. The measurement system used and the tested power LEDs are described. The results of measurements of the junction temperature of the tested devices, the values of the average value of the power dissipated in the tested devices and the photometric and radiometric parameters of these devices obtained for different values of frequency and the duty cycle of the signal controlling the current flowing through the tested diodes are presented and discussed. It is shown that the operation of the considered semiconductor devices is more effective at low frequency values. The possibility of adjusting the optical parameters of the power LEDs in the considered range of frequency and the duty cycle adjustment is assessed. Additionally, the measured waveforms of the current supplying the tested LEDs is shown. The influence of the parasitic capacitances of the tested devices is discussed. On the basis of the obtained investigation results, some recommendations for the designers of lighting systems can be formulated. In order to obtain an almost linear dependence of the illuminance on the duty cycle, the values of frequency not exceeding 10 kHz should be used. [ABSTRACT FROM AUTHOR]

Induction motors are typical motors with a constant speed that do not function at synchronous rates. Industrial mechanical loads must not only be powered but also operated at the specified velocity. Consequently, it is necessary to have ways of controlling the speed of induction motors. Multiple techniques exist for regulating the velocity of an induction motor. The objective of this paper is to critically examine the existing literature on different speed control techniques and evaluate their effectiveness in the presence of harmonics. Specifically, the focus will be on the utilization of SPWM inverter, harmonics reduction, and speed-torque characteristics to identify the most efficient methods. Additionally, the paper aims to explore strategies for minimizing odd harmonics through the use of an inverter. [ABSTRACT FROM AUTHOR]

The grid-connected inverter is the key component for the reliable and safe operation of grid-interconnected renewable energy systems. In order to ensure that the inverter output current is in-phase synchronized with the grid voltage, a highly efficient and fast control strategy is required. This paper proposes an algorithmically driven approach for designing the adaptive controller for a grid-connected DC/AC inverter. The controller consists of two adaptive IIR filters based on the LMS algorithm and has two modes of operation. During the learning mode, the controller uses the filters to estimate the coefficients of the inverse transfer function of the PWM-driven inverter at several grid frequencies within a specific range. During the online mode, the controller generates the driving signal for the inverter block using a set of learned coefficients corresponding to the current grid frequency. By constantly monitoring the grid voltage and reconfiguring the controller accordingly, a fast adaptation of the inverter output current to grid frequency variations is achieved. For grid frequency variations in the range of 48 to 52 Hz, the MATLAB simulation results show that the phase difference between the grid voltage and inverter output current waveforms becomes less than 1 degree after at most four periods. [ABSTRACT FROM AUTHOR]

Summary: The voltage quality issues shows the significant effect on the performance of radial secondary distribution feeder. This paper aims to enhance the voltage regulation of radial secondary distribution feeder system using 5‐level TCHB inverter based dynamic voltage restorer. Series voltage drop is the major factor causes poor voltage regulation. A 5‐level TCHB inverter based DVR is used to inject the same amount of voltage dropped by series impedance. The DVR injects voltage with proper magnitude, phase and frequency with the proposed single phase PLL based SRF control circuitry. This enhances the voltage regulation by maintaining the load voltage at its rated value. Both the simulation and hardware results shows the enhancement of voltage regulation with mitigation using DVR. [ABSTRACT FROM AUTHOR]

Summary: The intrinsic characteristics such as modular structure, filterless operation, and absence of DC‐link capacitor have made the modular multilevel converter (MMC) superior to the conventional multilevel converters. However, the submodule (SM) capacitor voltage balancing is crucial. This paper presents a voltage balance control method for MMC. The proposed method generates 2N + 1 levels (where N is the number of SMs per arm) which halves the step size of output voltage and improves the harmonic performance as compared to N + 1 level generation. It requires only one carrier per phase and no voltage and current measurements are needed for the implementation. Therefore, the proposed method makes the system cost‐effective and reduces the implementation issues related with carrier‐based methods substantially. It also alleviates the non‐uniform charge distribution problem with the phase disposition pulse width modulation (PDPWM) technique. Further, a detailed mathematical analysis is presented which enhances the understanding of balancing algorithm. In addition to this, the circulating current with 2N + 1 modulation is analyzed and a control technique is presented. The proposed voltage balancing method is simulated comprehensively in MATLAB/SIMULINK software and validated by the experimental results obtained from a laboratory prototype. [ABSTRACT FROM AUTHOR]

Use of Pulse Width Modulation (PWM) techniques has enabled the converters to be used in low‐frequency high‐power applications. The main objectives of PWM are to reduce the line current harmonic, switching energy loss, and torque pulsation and motor acoustic noise (for motor drive applications). This paper mainly deals with selective harmonic elimination PWM (SHEPWM), Hysteresis current controlled PWM (HCPWM), space vector PWM (SVPWM), bus‐clamping PWM (BCPWM), and the most advanced wavelet PWM technique (WPWM). Different conventional as well as advanced soft computing techniques have been discussed for SHEPWM in order to solve the complex non‐linear transcendental equations and obtain the optimized switching angles. The paper also deals with different conventional and advanced bus clamping sequences that have shown superior result in mitigating the switching loss. In order to judge the true performance of SHEPWM and CSVPWM in terms of accuracy of obtaining the switching angles, convergence rate, THD, torque ripple, switching energy loss, etc., a common experimental test bench consisting of three‐phase, two‐level, six switch inverter coupled with a 2 hp, 50 Hz, three‐phase induction machine has been formed. The selected BIA‐based SHEPWM and CSVPWM have been implemented in the MATLAB simulation software, and the same has also been applied to the experimental test bench through dSPACE 1104 DAC card. Performance of HCPWM and different BC‐PWM sequences has also been verified using the same experimental test bench. This manuscript will help the researches and practitioners working in this field, to gain a clear idea about the type of PWM to be used for their specific application in order to achieve superior performance. [ABSTRACT FROM AUTHOR]

Multi-level converter (MLI) topologies are increasingly being used in medium and high-power applications due to their numerous benefits, including lower power loss in power switches, minimal harmonic distortion, and reduced Electromagnetic Interference (EMI) noise in inverters. The objective of this study is to present a new multi-level symmetric inverter topology that can be efficiently controlled. The study aims to identify the positions of different switches in the architecture, select suitable switches, and propose a control technique that can minimize harmonic distortion while generating an ideal output voltage/current. Compared to conventional inverters with the same number of levels, the suggested topology involves fewer switching devices and voltage sources, with minimal voltage drop (Vstress) in the switches and Total Harmonic Distortion (THD). This reduces losses and improves model efficiency. In order to demonstrate the working principle of the new topology, a seven-level single-phase inverter is used, and the topology's study and validation are carried out for different modulation indices in the MATLABSIMULINK environment. [ABSTRACT FROM AUTHOR]

In this article, an active rectifier with pulse width modulation (PWM) mode on- and off-delay compensation technique is proposed. Conventional delay compensation modes: current mode, voltage mode, and delay-based mode are discussed respectively. Also, the adaptive delay compensation technique and potential disturbance problems are analyzed. To achieve wide and flexible delay compensation range, the proposed rectifier adopts current mode delay compensation methods to eliminate on- and off-delay. Moreover, PWM mode feedback loops are built to compensate circuit delays adaptively under various process, voltage, and temperature (PVT) and loading conditions. Compared with previous works, the proposed PWM mode technique converts the fluctuant error voltages into the fixed duty cycle signal in each cycle, avoiding the disturbance on compensation current and even error flips of comparators. The stability of the current compensation is improved. The proposed active rectifier was designed and fabricated in $0.18\mu \text{m}$ CMOS process. Both TX and RX coils are designed and fabricated on printed circuit board (PCB), and the diameter is limited below 3cm. Measurement results show that, with the input sine voltage amplitude ranging from 1.5V to 2.4V and 2MHz operating frequency, the peak power conversion efficiency (PCE) achieves 91.7% under $200\Omega $ loading resistor and the peak voltage conversion ratio (VCR) achieves 93.7% with $500\Omega $ loading resistor. The maximum output power reaches 57.6 mW. Compared with the case with no PWM mode delay compensation, the measurement PCE and VCR are improved by at least 9%. The proposed rectifier achieves better dynamic performance and is suitable for wireless power transfer (WPT).

This work proposes a novel pixel circuit using analog pulse width modulation (PWM) for micro light-emitting diode (micro-LED) displays. The proposed circuit generates uniform sweep waveforms and driving currents to control micro-LED emission precisely by compensating for threshold voltage (VTH) variations of p-type low-temperature polycrystalline silicon thin-film transistors (LTPS TFTs) and VDD current-resistance drops (I-R drops). Driven by the PWM method, micro-LED can operate with high wall-plug efficiency (WPE), leading to low power consumption. To analyze the circuit performance, the electrical characteristics of a micro-LED and LTPS TFTs are measured to establish the simulated models. The HSPICE simulation results present that the current error rates and time shift rates of emission currents are below 1.65% and 2.75%, respectively, with ±0.3 V variations in VTH and 1.2 V drops in VDD. Furthermore, the power improvement relative to a 7T1C pulse amplitude modulation (PAM) circuit is higher than 19.05% at all gray levels, confirming that the proposed circuit is suitable for use in micro-LED displays.

This paper proposes a bidirectional three-level T-type LLC resonant DC-DC converter operating with phase-shift control, which is simple and effective, variable frequency modulation to perform soft switching in a wide voltage ratio range and light loads, and pulse width modulation to reduce reactive circulating current. In this combined modulation method, three control parameters: switching frequency, the duty cycle of switches in the vertical arms, and phase shift between primary and secondary switches, are changed depending on the voltage conversion ratio and load. The circuit operates as LLC resonant in forward operation and series resonant in reverse operation. Thus, LLC and series resonant analyses of the proposed converter, operated in continuous conduction mode and buck mode, are presented. A simplified frequency domain analysis, including all harmonics, is used in the theoretical calculations. Thus, the control parameters are accurately calculated for forward and reverse operations. The current, voltage, and power formulas in the working principle of the converter are derived, and an analysis of the control parameters and zero voltage switching region is performed. Soft switching analysis is done by considering the junction capacitor of the MOSFET and the dead time. The theoretical performance of the proposed modulation method has been verified with a 2 kW prototype. Soft-switching and loss analyses of the proposed converter have also been investigated under different load conditions and voltage conversion ratios. The proposed LLC resonant topology and modulation method improved significantly more efficiency than the phase-shifted modulated T-type converter under 30-100% load conditions.

The use of pulse width modulation (PWM) to drive permanent magnet synchronous motors (PMSM) inevitably creates current harmonics. The generated current harmonics create harmonic components of the electromagnetic force, causing noise and vibration in the PMSM and affecting the applied system. In this paper, the effect of PMSM’s electromagnetic force on noise and vibration of a reciprocating compressor is analyzed. First, two PMSMs with different electromagnetic forces were designed. As the driving method, space vector PWM (SVPWM) was used, and the experimental current waveform was analyzed. Based on the Maxwell stress tensor method, the electromagnetic force of the PMSM was calculated and the noise/vibration characteristics were analyzed. Compressors were manufactured with two PMSMs with different electromagnetic forces and the noise/vibration test results were compared. The electromagnetic force of PMSM affected the noise of the compressor, especially in the domain of twice the carrier frequency, but did not affect the low-order vibrational displacement of the compressor. The finite element analysis method was used, and it was experimentally verified with the manufactured motor and compressor.