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Grid-connected systems are increasingly becoming essential complements to existing electricity infrastructures in many developed countries. Among renewable energy systems, photovoltaic (PV) panels are the most utilized and efficient. However, integrating PV systems into the main grid presents substantial challenges. To overcome these issues, this paper presents a comprehensive approach through the design, control, and hardware implementation of a cost-effective grid-connected PV (GPV) system. Focusing on practical and economical solutions, this research transcends theoretical simulations by developing a tangible laboratory-scale prototype. This prototype integrates both power and control subsystems to ensure efficient and reliable operation of GPV systems. The power subsystem comprises a three-phase inverter, an LCL filter, and an interface circuit, forming the core hardware for energy conversion and grid connection. The control subsystem incorporates enhanced and advanced control techniques to optimize performance. These include the DSOGI-PLL synchronization algorithm, which guarantees precise grid voltage phase angle detection even when noise and higher-order harmonics are present, facilitating seamless grid integration. Additionally, the Space Vector Pulse Width Modulation (SVPWM) algorithm is employed to control the three-phase voltage source inverter, providing superior DC-link voltage utilization and harmonic performance. A robust current PI controller is also implemented, offering excellent steady-state response and resilience against system parameter variations. The results obtained have proven that the connection of the proposed system can be successfully achieved and implemented. This work promotes the widespread adoption of photovoltaic systems and contributes to global sustainable energy initiatives. [ABSTRACT FROM AUTHOR]

In response to the challenges posed by large-scale, uncoordinated electric vehicle charging on the power grid, Vehicle-to-Grid (V2G) technology has been developed. This technology seeks to synchronize electric vehicles with the power grid, improving the stability of their connections and fostering positive energy exchanges between them. The key component for implementing V2G technology is the bidirectional AC/DC converter. This study concentrates on the non-isolated bidirectional AC/DC converter, providing a detailed analysis of its two-stage operation and creating a mathematical model. A dual closed-loop control structure for voltage and current is designed based on nonlinear control theory, along with a constant current charge–discharge control strategy. Furthermore, midpoint potential balance is achieved through zero-sequence voltage injection control, and power signals for the switching devices are generated using Space Vector Pulse Width Modulation (SVPWM) technology. A simulation model of the V2G system is then constructed in MATLAB/Simulink for analysis and validation. The findings demonstrate that the control strategy proposed in this paper improves the system's robustness, dynamic performance, and resistance to interference, thus reducing the effects of large-scale, uncoordinated electric vehicle charging on the power grid. [ABSTRACT FROM AUTHOR]

Inverter-based systems encounter significant challenges in mitigating common-mode voltage (CMV) and minimizing inverter losses. Despite various space vector pulse-width modulation (SVPWM) techniques proposed to address these issues, a comprehensive comparative analysis has been lacking. This paper addresses this gap through an experimental and simulation-based evaluation of nine SVPWM techniques. A new discontinuous SVPWM technique, DSVPWM-K4, is introduced, which involves reversing the use of the two zero vectors in DSVPWM-K3. DSVPWM-K3 delivers superior performance in terms of CMV reduction, total harmonic distortion (THD), and inverter losses across all modulation indices (MI = 1, 0.75, 0.5, and 0.25), making it the most effective overall. Although DSVPWM-K4 is a novel approach, it ranks second in effectiveness. The RSPWM technique achieves the lowest CMV with a zero peak-to-peak value but is most effective at lower modulation indices (0.25 and 0.5) due to higher harmonic distortion at higher modulation indices. AZSPWM performs optimally at higher modulation indices, providing a 66.66% reduction in CMV compared to continuous SVPWM and significantly lower THD compared to RSPWM. In contrast, NSPWM exhibits nearly double the THD compared to continuous SVPWM. [ABSTRACT FROM AUTHOR]

This paper investigates the thermal operating capability of an interior permanent magnet synchronous machine. An iterative workflow is presented, combining electromagnetic modeling, control, power‐loss modeling, and thermal modeling to identify maximum thermal stable operating points. Special attention is given to the critical temperatures of winding and permanent magnets. A nonlinear reduced order model based on finite element method model was used to simulate the system, including an inverter model with space vector pulse width modulation in combination with field‐oriented control. Furthermore, an advanced iron core loss model and thermal lumped parameter model were employed. The presented approach allows for evaluating losses and their impact on steady‐state temperatures. The obtained results highlight the significant influence of space vector pulse width modulation on iron core losses and the importance of considering both advanced power‐loss models and adequate thermal models when analyzing the machine's thermal state. This research emphasizes the concept of a thermally stable envelope, providing a comprehensive understanding of the thermal boundaries under various operating conditions. [ABSTRACT FROM AUTHOR]

Summary: In a unidirectional five‐level ac motor drive system with open‐end winding connection, because of the variation of operating frequency of ac motor, the instantaneous power fluctuation of rectifier stage and inverter stage will generate larger voltage ripple on each phase dc‐link capacitors, and further lead to a large amount of current harmonics in output currents of inverter. To cope with this problem, an improved space vector pulse width modulation (SVPWM) strategy based on dc‐link voltage feedforward is proposed. In this paper, the effects of zero sequence current harmonics caused by dc‐link voltage ripple on ac motor are firstly analyzed, including the stator winding flux linkage equation, voltage equation, and electromagnetic torque. Then, the generating mechanism of dc‐link voltage ripple and the current harmonics are discussed in detail in terms of instantaneous power fluctuation of each single‐phase converter. Based on this, an improved SVPWM strategy by modifying the modulation signal is proposed to suppress the generation of current harmonics. Finally, a 2.2 kW prototype experimental results are given, which verify the feasibility and advancement of the proposed modulation strategy. [ABSTRACT FROM AUTHOR]

Achieving precise stopping of electric locomotives is crucial for the realization of intelligent and unmanned auxiliary transportation systems. Presently, human drivers play a central role in ensuring accurate stopping, presenting obstacles to automation and cargo location precision, especially within the coal mining sector. This article centers on achieving the precise stopping of electric locomotives under various conditions through the utilization of permanent magnet synchronous motor-driven locomotives. This approach introduces a novel stopping control method that integrates a fuzzy proportional–integral–derivative (F-PID) controller with a vector control model for permanent magnet synchronous motors (PMSM). Subsequently, we develop the F-PID controller using the PMSM technique, incorporating new fuzzy rules for each subsystem to enhance control accuracy and efficiency. Finally, extensive simulations and real-world experiments are conducted on an electric locomotive stopping test bed to validate the effectiveness of the proposed control method. The results show that the method consistently achieves precise stopping under diverse working conditions, with an error of less than 0.3 m, confirming its robustness and reliability. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Zhengzhou University: Engineering Science is the property of Editorial Office of Journal of Zhengzhou University: Engineering Science 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.)

The primary objective of the proposed work is the design of a Hybrid Teaching Learning-based Horse Herd Optimization Algorithm regulated Fractional Order Tilt Derivative Acceleration with Filter (TLBO-HHOA regulated FOTDAF) controller for enhanced performance and enhanced devaluation of harmonic components of the grid-connected photovoltaic system. The solar photovoltaic system incorporates constituents such as a photovoltaic array, interleaved fractional order boost converter (IFOBC), Reduced Switch Multilevel Inverter (RSMI), and TLBO-HHOA regulated FOTDAF controller. IFOBC is preferred over boost converter because of its low ripple voltage, faster transient response, high efficiency, low duty cycle, reduced EMC, and improved reliability and stability. In this control strategy, the control logic is formulated by using a Tilt Integral Derivative Controller (TIDC), whose control parameters are considered as a function of the error to improve the robustness. The validation, better performance, and superiority of TLBO-HHOA regulated FOTDAF are established by comparative result analysis using modern controllers. This study implements TLBO-HHOA-regulated FOTDAF and applies Support Vector Pulse Width Modulation (SVPWM) technique. The proposed model managed to achieve improvements in overall system response and reduced harmonic distortions as well as better accuracy, improved stability, improved robustness, and better capabilities to handle system uncertainties.

In response to the challenges posed by large-scale, uncoordinated electric vehicle charging on the power grid, Vehicle-to-Grid (V2G) technology has been developed. This technology seeks to synchronize electric vehicles with the power grid, improving the stability of their connections and fostering positive energy exchanges between them. The key component for implementing V2G technology is the bidirectional AC/DC converter. This study concentrates on the non-isolated bidirectional AC/DC converter, providing a detailed analysis of its two-stage operation and creating a mathematical model. A dual closed-loop control structure for voltage and current is designed based on nonlinear control theory, along with a constant current charge–discharge control strategy. Furthermore, midpoint potential balance is achieved through zero-sequence voltage injection control, and power signals for the switching devices are generated using Space Vector Pulse Width Modulation (SVPWM) technology. A simulation model of the V2G system is then constructed in MATLAB/Simulink for analysis and validation. The findings demonstrate that the control strategy proposed in this paper improves the system’s robustness, dynamic performance, and resistance to interference, thus reducing the effects of large-scale, uncoordinated electric vehicle charging on the power grid.

Inverter-based systems encounter significant challenges in mitigating common-mode voltage (CMV) and minimizing inverter losses. Despite various space vector pulse-width modulation (SVPWM) techniques proposed to address these issues, a comprehensive comparative analysis has been lacking. This paper addresses this gap through an experimental and simulation-based evaluation of nine SVPWM techniques. A new discontinuous SVPWM technique, DSVPWM-K4, is introduced, which involves reversing the use of the two zero vectors in DSVPWM-K3. DSVPWM-K3 delivers superior performance in terms of CMV reduction, total harmonic distortion (THD), and inverter losses across all modulation indices (MI = 1, 0.75, 0.5, and 0.25), making it the most effective overall. Although DSVPWM-K4 is a novel approach, it ranks second in effectiveness. The RSPWM technique achieves the lowest CMV with a zero peak-to-peak value but is most effective at lower modulation indices (0.25 and 0.5) due to higher harmonic distortion at higher modulation indices. AZSPWM performs optimally at higher modulation indices, providing a 66.66% reduction in CMV compared to continuous SVPWM and significantly lower THD compared to RSPWM. In contrast, NSPWM exhibits nearly double the THD compared to continuous SVPWM.

An open-end winding arrangement is fed with two typical 2-level voltage source inverters (VSIs) on either side to accomplish multilevel inversion. Two voltage source modules (VSIs) DC-link voltages are kept at a 2:1 ratio to realize the open-end winding induction motor (OEW-IM) power circuit's four-level configuration. However, the higher DC-link voltage capacitor overcharges its lower DC-link voltage counterpart in the 4-level power circuit configuration. This article proposes a new hybrid-clamping space vector PWM (SVPWM) approach to prevent overcharging. Based on the sample moment, the suggested SVPWM technique clamps one inverter and switches to another inverter. Additionally, it clamps one of the inverter's switching phases. The proposed PWM method has been found to reduce switching power loss in contrast to earlier SVPWM methods. The proposed SVPWM scheme for the 4-level OEW-IM drive is tested and verified using an experimental laboratory setup. [ABSTRACT FROM AUTHOR]

The primary objective of the proposed work is the design of a Hybrid Teaching Learning-based Horse Herd Optimization Algorithm regulated Fractional Order Tilt Derivative Acceleration with Filter (TLBO-HHOA regulated FOTDAF) controller for enhanced performance and enhanced devaluation of harmonic components of the grid-connected photovoltaic system. The solar photovoltaic system incorporates constituents such as a photovoltaic array, interleaved fractional order boost converter (IFOBC), Reduced Switch Multilevel Inverter (RSMI), and TLBO-HHOA regulated FOTDAF controller. IFOBC is preferred over boost converter because of its low ripple voltage, faster transient response, high efficiency, low duty cycle, reduced EMC, and improved reliability and stability. In this control strategy, the control logic is formulated by using a Tilt Integral Derivative Controller (TIDC), whose control parameters are considered as a function of the error to improve the robustness. The validation, better performance, and superiority of TLBO-HHOA regulated FOTDAF are established by comparative result analysis using modern controllers. This study implements TLBO-HHOA-regulated FOTDAF and applies Support Vector Pulse Width Modulation (SVPWM) technique. The proposed model managed to achieve improvements in overall system response and reduced harmonic distortions as well as better accuracy, improved stability, improved robustness, and better capabilities to handle system uncertainties. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic 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.)

The main focus of this study is the minimization of Permanent Magnet Synchronous Motors (PMSM) steady-state speed error. In order to do this, a Lyapunov candidate function that contained the speed error is defined and a Based Lyapunov Theory (BLT) speed controller is designed. The novelty of this paper is the smoother pre-filter applied to the reference speed guarantees the stable operation of the nonlinear controller at step change in reference signal. The pre-filter design is carried out in a way that does not have a negative effect on the settling time, which is one of the step response characteristics. A proportional-integral (PI) speed controller is designed for comparison. FOC technique is used for inverter control. As the speed controller of the system, PI and BLT controllers are designed separately. Simulation studies are run in MATLAB/Simulink. PI speed controller coefficients are determined using the pole assignment method. For this purpose, PI coefficients for operating the controller at the selected frequency and the desired damping ratio are calculated. Stability analyses are carried out for PI and BLT speed controllers. A low pass filter that allows the system to apply a smoothed reference speed is designed in order to eliminate the range in which the derivative of the reference speed used in the BLT speed controller is undefined. Three different simulations are modeled. In the first one, the reference speed is changed in both directions by step function, under constant load torque. The speed and torque performances of both speed controllers are compared with the performance criteria including settling time, overshoot, peak value, peak time, root mean squared error (RMSE), and integral of time weighed absolute error (ITAE), and the results of the comparison are shown in figures and tables. In addition, a second simulation including reference load changes is made to model load torque disturbance as a robustness test, and a third simulation containing resistance changes is made to model parameter uncertainty are carried out. Both transient response and steady state response of controllers against parameter changes are examined in simulation 2 and 3. With the proposed BLT controller, the transient and steady-state response of the speed is improved both at the time of torque change and at the time of winding resistance change. The results are given in figures and tables. [ABSTRACT FROM AUTHOR]

The paper presents a comprehensive study on modeling a doubly fed induction generator (DFIG) and explores various control strategies for pulse-width modulation (PWM) in back-to-back (B2B) converter techniques. A DFIG is characterized by a wound rotor and three slip-ring induction machines, with the stator winding directly connected to the power grid and the wound rotor interfaced with the grid through a 3-phase AC/DC/AC converter. Typically, the converter connected to the grid is referred to as the grid side converter (GSC), while the converter attached to the rotor's slip-ring circuit is termed the rotor side converter (RSC). This research delineates various PWM-based B2B converter methodologies applied to the DFIG within wind energy turbines, aiming to regulate the RSC for optimal power capture. The study employs MATLAB/SIMULINK for constructing a multi-phase voltage source converter two-level (VSC-2L) model, leveraging different PWM techniques including Sine-PWM, Sinusoidal-PWM with third harmonic injection (THIPWM), and space vector PWM (SVPWM). These techniques are assessed based on total harmonic distortion (THD) using fast Fourier transform (FFT) analysis. The findings indicate that SVPWM offers several advantages, such as ease of digital implementation, lower THD, reduced switching frequency losses, and more efficient utilization of the DC link voltage, thereby enhancing control strategy effectiveness. [ABSTRACT FROM AUTHOR]

Split-source inverter (SSI) has been recently developed as an alternative to the commonly used ZSI where it can serve an interface between the renewable energy sources and the common grid. This paper presents a mathematical model and control strategy for grid-connected SSI system with either constant voltage source or photovoltaic (PV) source. The control strategy is based on linear PI controllers which are fine-tuned by the frequency loop shaping method with the help of the derived mathematical model to ensure the stability of the system with robust dynamic behavior. The derived mathematical model provides a straightforward and efficient understanding of the dynamics resulting from the interaction between the PV and the SSI grid-connected system. The simulation results indicate that the system has a robust dynamic behavior when subjected to various transient conditions. Finally, a downscaled prototype of SSI grid-connected system is implemented to experimentally validate both the mathematical model and control strategy.

With the development of the times, elevator has become an essential transportation in our life. In order to meet the comfort of elevator operation, this paper investigates the design of the speed control system of elevator permanent magnet synchronous traction motor in combination with the elevator operation curve. The whole system is based on SVPWM and uses direct torque control combined with fuzzy adaptive PID to achieve accurate control of motor running speed. It includes the input signal module, control module, drive module and feedback module. Firstly, the analysis of each module in the system is completed, and the connection between the modules is established, as well as the control system. Then case studies are carried out on MATLAB/SIMULINK, and the actual running speed curve of the elevator is obtained, and the simulation results are analyzed to verify the stability and reliability of this speed control system and complete the design.

The significance of electric vehicles is progressively escalating, underscoring the criticality of technologies underpinning the functionality of their propulsion systems. This particular case study delves into the simulation of field-oriented control, coupled with field weakening, aimed at regulating a salient-pole permanent-magnet synchronous motor (PMSM). This approach involves the utilization of two cascaded loops for current and voltage, each employing PI controllers. The fine-tuning of these controllers' parameters hinges on the motor characteristics, as well as the desired response bandwidth. [ABSTRACT FROM AUTHOR]

In this article, a novel Euclidean distance mapping (EDM) technique for space vector pulse width modulated (SVPWM) voltage source inverter (VSI) is presented. The EDM technique processes space vector diagram (SVD) as an image, which simplifies execution of SVPWM. In the proposed technique, Euclidean distance calculation between all eight switching vectors and the tip of the revolving reference voltage vector for every subcycle is carried out. The identification of nearest three voltage vectors (NTV) and switching sequence designs are done on the basis of these Euclidean distances. The EDM-SVPWM technique achieves improvement in the inverter performance in the context of the factors like stator flux ripple over a subcycle, distortion factor (DF), total harmonics distortion (THD) of line voltage, and line current ripple of the inverter. The performance of EDM-SVPWM technique is verified analytically and confirmed experimentally by hardware implementation over the wide range of fundamental frequencies and modulation indices. [ABSTRACT FROM AUTHOR]

Split-source inverter (SSI) has been recently developed as an alternative to the commonly used ZSI where it can serve an interface between the renewable energy sources and the common grid. This paper presents a mathematical model and control strategy for grid-connected SSI system with either constant voltage source or photovoltaic (PV) source. The control strategy is based on linear PI controllers which are fine-tuned by the frequency loop shaping method with the help of the derived mathematical model to ensure the stability of the system with robust dynamic behavior. The derived mathematical model provides a straightforward and efficient understanding of the dynamics resulting from the interaction between the PV and the SSI grid-connected system. The simulation results indicate that the system has a robust dynamic behavior when subjected to various transient conditions. Finally, a downscaled prototype of SSI grid-connected system is implemented to experimentally validate both the mathematical model and control strategy. [ABSTRACT FROM AUTHOR]

In order to expand the operating speed range of wind turbines, reduce losses for the turbine units, and increase power generation, a SVPWM (space vector pulse width modulation) pulse over-modulation method based on carrier modulation is proposed in this paper. The method detects the modulation level of inverter output voltage and the speed of the permanent magnet motor in real time, and corrects the non-linear region of the SVPWM modulation waveform based on its modulation level and speed to ensure the maximum fundamental voltage output. At the same time, judging and calculating the interval and action time of the vector are unnecessary, and the judgment and calculation of the partition are simple. In addition, it is fully compatible with the carrier modulation method of the linear modulation region, and the modulation of intervals can transit smoothly, making it easy for engineering implementation. This method is applied to the operating conditions of permanent magnet wind turbines. The experimental results show that the operating speed range of the optimal power control of the turbines unit has been expanded by about 4%, and its effectiveness and practicality are verified.

This article presents a harmonic analysis of the stator currents of a squirrel-cage induction motor fed by a voltage source inverter with PWM space vector control (SVPWM). The influence of PWM switching frequency and dead time (dead band) of controlled transistors on THD and electromagnetic torque ripple is shown. The aim is to determine the lowest switching frequency of the transistors for which the drive will operate correctly. Characteristics were determined as functions in the form of THD ( f P W M ), where the least square approximation was used for stator current measurements when the PWM switching frequency was changed. The approximations were realized for simulation and experimental results. To clarify the results, the operation of hardware PWM circuits in microcontrollers is analyzed. [ABSTRACT FROM AUTHOR]

Over the past few years, there has been an increase in the use of open-end winding (OEW) PMSM applications. The fault tolerance of the topology makes OEW PMSM suitable for various intermittent operations. However, a dual inverter operation causes OEW PMSM drive schemes to exhibit high commutation and ripple. This paper presents an optimized alternative fixed switching 12-sector space vector pulse width modulation (svpwm) control for open-end winding PMSM drives. This work reduces the commutation number without compromising drive system performance. In comparison with conventional 6-sector svpwm, this control scheme offers three advantages. It incorporates optimal signal generation, a virtual state method for segmenting sectors into small sectors, and alternative fixed switching methods based on sub-hexagons. Inverters are assigned fixed voltage states based on sub-hexagon numbers. The proposed scheme was validated in the Matlab2021b Simulink environment. Based on the simulation results, it is found that the proposed scheme is effective for OEW PMSM. Finally, OPAL-RT (OP4500) is used to verify scheme effectiveness. The verification of the proposed scheme indicates its effectiveness. Results obtained from real-time hardware have ripple of 1.25% and 5% for speed and torque performance, respectively.

Pulse Width Modulation (PWM) driven power converters are widely used in realizing the function of rectification and inversion in renewable and emerging power applications. They play a key role in tying renewable energy sources of solar and wind to conventional energy grid systems. Such emergying styles of power systems are referred to as Distributed Generation (DG) or energy mix. The PWM-based switching devices are also sources for injecting harmonics to degrade the quality level in this emerging style of DG systems causing steady-state waveform distortion. Thus power converters operated by finely tuned PWM play an important role in mitigating the voltage waveform distorting harmonics and consequently improving the stability of the system. This paper presents the mitigation of harmonic contents by reproducing as a novel space vector-based switching pattern of SVPWM. In this work, the proposed switching pattern will have a DC link RMS current equal to or less than that of a conventional SVPWM current under the same switching frequency (SF), load, L-C filter, DC bus voltage, and Modulation Index (MI). The results include a 13.43% improvement in Total Harmonic Distortion (THD) at relatively high modulation indices. The Weighted Total Harmonic Distortion (WTHD) has also improved by 47.37% and the number of thyristors has been reduced lowering switching losses. The Matlab-Simulink simulation results have been experimentally verified with an Advanced Digital Analog Learning Module (ADALM M2k)-based experimental setup, improving the proposed SVPWM THD by 13.49%. The conventional and proposed SVPWM performance comparison is done by obtaining Fast Fourier Transform (FFT) by driving a two-level three-phase voltage source inverter.

This paper introduces a mathematical design and analysis of three-phase inverters used in electric drive applications such as aerospace, electric vehicles, and pumping applications. Different wide bandgap (WBG) semiconductor technologies are considered in this analysis. Using SiC MOSFETs and Si IGBTs, two drive systems are developed in order to show the improvement in the efficiency of the inverter. The efficiency, total losses of the drive systems and the power losses of two inverters are computed and compared for both drive systems at the same operating condition. The drive system with SiC MOSFET shows much better performance compared to the drive system with Si IGBT. The SiC MOSFET system provides a 59.39%, 86.13%, and 29.76% lower conduction losses, switching losses and drive's total losses, respectively, compared to the Si IGBT system. The efficiency of the SiC MOSFET system is 2.46%pu higher than the efficiency of the Si IGBT drive system. Moreover, this paper introduces a detailed analysis for the dc-link voltage and current ripples in three-phase inverters. Furthermore, the minimal dc-link capacitor needed to deal with the ripple current and voltage is investigated. Finally, the performance of the drive with Si IGBT is experimentally tested under different operating speeds and loads. [ABSTRACT FROM AUTHOR]