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Sparse modular multilevel converters (SMMCs) are a new type of lightweight high-voltage large-power AC/AC converter that significantly reduces the number of components compared to modular multilevel matrix converters (M3Cs). This study proposes a fault ride through a control strategy for SMMC to address the issues of arm energy imbalances and valve-side overvoltage, which occur during asymmetric faults on the low-frequency side. First, we establish models of the energy deviation of the arms under asymmetric short-circuit faults on the low-frequency side of SMMC. We also study the influence mechanism of the control strategies on the arm energy imbalance during faults. On this basis, an arm energy balancing strategy based on zero-sequence voltage injections combined with AC voltage control is proposed; this can achieve arm energy balance and suppress the negative sequence current and overvoltage of the SMMC. Finally, we construct a simulation model of an offshore wind power low-frequency transmission system based on the SMMC. The simulation results show that the proposed energy balance strategy can realize the stable operation of the low-frequency transmission system (LFTS) under asymmetric faults on the low-frequency side, that the maximum capacitor voltage deviation during the fault does not exceed 10% and that capacitor voltage returns to normal 0.25 s after the fault occurs. [ABSTRACT FROM AUTHOR]

A matrix converter (MC) converts an AC source voltage into a variable-voltage variable-frequency AC output voltage (direct AC-AC) without an intermediate DC-link capacitance. By eliminating the traditional DC-link capacitor, MCs can achieve higher power densities and reliability when compared to conventional AC-DC-AC converters. MCs also offer the following characteristics: total semiconductor solution, sinusoidal input and output currents, bidirectional power flow and controllable input power factor. This paper reviews the history, recent developments and commercialization of MCs and discusses several technical requirements and challenges, including bidirectional switches, wide bandgap (WBG) opportunities using GaN and SiC, overvoltage protection, electromagnetic interference (EMI) and ride-through in motor drive applications. MC design solutions and operation are discussed, including a comparison of control and modulation techniques as well as the detailed development of space vector modulation (SVM) to provide a deep insight into the control implementation and results. The paper concludes with compelling motor drive innovation opportunities made possible by advanced MCs including fully integrated and multiphase systems. For conventional MCs, size reductions of 30% are reported, as well as efficiencies of 98% and low input current total harmonic distortion of 3–5%. [ABSTRACT FROM AUTHOR]

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Copyright of Electric Power Automation Equipment / Dianli Zidonghua Shebei is the property of Electric Power Automation Equipment Press 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 new common-mode voltage (CMV) suppression strategy based on open-active vectors, which reduces the CMV peak value and suppresses the common-mode spikes caused by switching. In addition, the novel open-active vector is characterized, and its common-mode equivalent circuit is established. The new modulation strategy proposes open-active vectors in place of zero voltage vectors, which reduces the peak magnitude of the output CMV by 42.3%. While reducing the CMV, the complex commutation issue of the rectifier stage and the CMV spike issue brought on by the impact of the inverter stage dead zone are both resolved by the new modulation method. The effectiveness of the new strategy is verified by simulation and experimental results. [ABSTRACT FROM AUTHOR]

The modular multilevel matrix converter can provide frequency control support for remote AC power grids and has good application prospects in high-voltage low-frequency AC transmission systems. However, the dynamic performance of the traditional outer-loop PI controller is susceptible to changes in its own parameters and external conditions, which in turn influences the control effect. Therefore, a variable universe fuzzy proportional-integral (PI) adaptive outer-loop control strategy is proposed in this paper. Using the automatic sensing and self-adaptive capability of variable universe fuzzy control, the self-adaptation and self-adjustment of the size of the input error of the outer loop is achieved. Meanwhile, a function-based scaling factor approach is utilized to develop scaling factors for the input and output domains to enhance the control accuracy. Simulation and experimental findings demonstrate that this control strategy advances system stability and reinforces the self-adaptive adjustment capability of outer-loop control when compared to preexisting approaches. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of the operational characteristics of three-phase AC–DC matrix converters, which operate as rectifiers but possess a range of additional capabilities. These include the ability to reverse the power flow, control the input power factor, and generate a multilevel output voltage. The analysis yields a modulation strategy that minimizes switching losses. The proposed modulation strategy is compared with seven well-known space vector modulation strategies in terms of efficiency and distortion of input and output current. The performance is experimentally validated. [ABSTRACT FROM AUTHOR]

Introduction. This paper delves into the practical application of multilevel technology, particularly focusing on the capacitor-clamped converter as a promising solution for medium-to-high voltage power conversion, with specific emphasis on direct AC-AC switching conditions. Problem. The limitations of conventional single-cell matrix converters (MC) in efficiency and performance for medium-to-high voltage power conversion applications are well-recognized. Goal. The primary objective is to investigate the performance of the 3 phase modular multilevel matrix converter (3MC) with three flying capacitors (FCs) modeling. This investigation utilizes the Venturini method for gate pulse generation, aiming to compare the performance of the 3MC with standard converter designs. Methodology. To achieve the research goal, the Venturini method is adopted for generating gate pulses for the 3MC, representing a departure from conventional approaches. Detailed simulations employing MATLAB/Simulink are conducted to comprehensively evaluate the performance of the 3MC in comparison to conventional converter designs. Results. The simulation outcomes reveal a significant reduction of 73 % in total harmonic distortion (THD) achieved by the 3MC. This reduction in THD indicates improved robustness and suitability for medium-to-high voltage power conversion systems necessitating direct AC-AC conversion. These results highlight the efficacy of the 3MC in enhancing power conversion efficiency and overall performance. Originality. This paper contributes novel insights into the practical implementation of multilevel technology, particularly within the realm of capacitor-clamped converters. Furthermore, the utilization of the Venturini method for gate pulse generation in the 3MC represents an original approach to enhancing converter performance. Practical value. The research findings present significant advancements in multilevel transformer technology, offering valuable guidance for optimizing transformer design in various industrial and renewable energy applications. These contributions serve to enhance the development of reliable and efficient power systems, addressing critical needs in the energy sector. [ABSTRACT FROM AUTHOR]

The effectiveness of application of matrix converter method at eddy current testing (ECT) is studied in the work. Advantages of eddy current matrix application are analyzed, which include improvement of sensitivity to small defects, shortening of the total control time and improvement of the probability of detection of various types of defects. To evaluate their effectiveness, a dimensionless coefficient is proposed, which takes into account the inspection time, the reliability of defect detection, and the sensitivity to defects of a certain size. Experimental studies on specimens with artificially induced defects of different dimensions, types and orientation confirmed the rationality of application of this coefficient for testing parameter optimization, in order to improve defect detection in structural elements. The influence of various factors, such as condition of the surface, sensor configuration in the matrix and verification parameters on the productivity of ECT hardware and software with matrix converters was additionally analyzed. Obtained results will promote better understanding of the possibilities and limitations of matrix application in ECT of the components of transport, aviation and defense equipment. It will allow optimizing the strategies of checking the tested products, improving the reliability of defect detection and general maintenance practices in many industries. [ABSTRACT FROM AUTHOR]

ABSTRACT Conventional nonisolated bidirectional DC‐DC converters are limited because of their low conversion voltage ratio. To overcome the limitation, this paper proposed a new bidirectional DC‐DC converter to introduce the novel regenerative configuration merged with the switched inductor technique for high voltage conversion applications. This design enables extreme DC‐voltage conversion with a minimal number of semiconductors and passive components. As a result, the converter's cost is reduced, and it can attain a high voltage gain with less duty ratio. In general, ultra‐gain converters suffer from high current stress across the input and output side switches in the step‐up and step‐down modes. To reduce high current stress, an active network configuration is imposed in the proposed converter. This paper describes the operating principle, steady‐state analysis of the voltage gain, and presents the performance matrices of the proposed converter. Furthermore, a comparative analysis is made with conventional and recent literature converters. Finally, a 350‐V, 500‐W, and 20‐kHz experimental prototype has been fabricated to validate the operation and corroborate the theoretical waveforms with experimental results. [ABSTRACT FROM AUTHOR]

ABSTRACT In recent years, in order to alleviate global environmental problems, renewable energy power generation and the electric vehicle industry have been vigorously promoted by many countries. During this background, many scholars have proposed the development of vehicle‐to‐grid (V2G) systems to alleviate the impact of renewable energy generation on grid quality, and electric vehicle charging piles are the core part of realizing V2G systems. This article proposes an ultra‐high voltage AC/DC isolated matrix converter applied to V2G electric vehicle charging piles, which can achieve bidirectional flow of energy, and proposes the control strategy that can reduce the current stress of the device. In addition, the ultra‐high voltage module of the proposed topology can provide wide voltage range and high voltage charging power for different types of electric vehicles. The proposed topology and control strategy are verified by simulation. [ABSTRACT FROM AUTHOR]

ABSTRACT This article presents a comprehensive investigation into the improved operation of an in‐direct matrix converter (IMC) through the application of improved pulse width modulation (PWM) techniques. Matrix converters (MCs) draw a discontinuous and distorted input current from the AC source, reducing the input power factor and increasing harmonics. The primary objectives of this work are to maximize the DC‐link voltage and improve source current while simultaneously minimizing switching losses and the total harmonic distortion (THD) of the load voltage, thereby improving power quality standards. To achieve these goals, a symmetrical space vector PWM technique (SSVPWM) is employed on the rectifier side, and an improved bus‐clamping PWM technique (BCPWM) is implemented on the inverter side. By strategically controlling the switching patterns, the DC‐link voltage is maximized while adhering to the voltage and current constraints of the switching devices, which improves the input power factor and hence the overall power quality. Additionally, this technique optimizes the operation of the IMC, leads to a reduction of current ripple, and reduces switching losses, thereby leading to higher efficiency. The core principle behind this research lies in the decoupled control of the rectifier and inverter stages, allowing for independent optimization and maximum system performance. By carefully manipulating the modulation indices, the harmonic content in the output voltage is significantly minimized which is vital for applications requiring a high‐quality and low‐distortion power supply. Simulation studies substantiate the efficacy of the independent control approach, showcasing improvements in DC‐link voltage maximization, switching loss reduction, and reduced output voltage THD. Furthermore, the validation of the real‐time implementation of this study was carried out making use of the OPAL‐RT (OP4510) real‐time simulator. [ABSTRACT FROM AUTHOR]

Copyright of Tikrit Journal of Engineering Sciences is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) 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.)

Summary: The LC filter integrated quasi‐Z source indirect matrix converter (QZS‐IMC) filters the input voltages and currents while highly expanding voltage boost ratio through the combined QZS network, avoiding the additional input filter while maintaining full‐silicon solution. The traditional proportional‐integral (PI) control method of IMC is realized through the PI regulators with pulse width modulation (PWM), which is complicated due to elaborated vectors computation and duty cycle composition of IMC and extra control loops design is mandatory. This paper proposes a model predictive control (MPC) for the LC filter integrated QZS‐IMC. Based on the established discrete models of circuit voltages and currents, the proposed control method measures the present circuit variables and predicts the variables in the next sampling period. Then, a predefined cost function is evaluated with the predictions and references at each active switching states of the IMC. An optimal switching state that ensures the smallest value of the cost function is applied to the power devices at the beginning of next sampling time. Simulation and experiment are carried out to demonstrate effectiveness of the proposed MPC for the LC filter integrated QZS‐IMC. [ABSTRACT FROM AUTHOR]

Summary: This paper targets to minimize the peak common mode voltage (CMV) in ultra sparse matrix converters (USMC) by applying new zero vectors for the space vector modulation technique (SVM). Conventional zero vectors in the SVM raise the peak CMV by 42.23%. An increased magnitude of CMV is associated with the occurrence of leakage current, hence resulting in insulation degradation. So, the reduction of peak CMV is necessary for USMC. The proposed method offers suitable switching arrangements using auxiliary shoot through (AST) switches to minimize the peak‐to‐peak CMV. This proposed method holds the advantages of the conventional method, like a wide range of modulation index and zero current switching at the rectifier side, and also reduces the CMV problem. This paper also provides a comparative analysis of the existing reported methods and the proposed method. The effectiveness of the proposed method is validated through both simulation and experimental results. [ABSTRACT FROM AUTHOR]

In this paper, a voltage control system for a PMSM motor based on the QZSDMC converter is proposed, which allows operation in both buck and boost modes as a possible method to make the drive resistant to power grid voltage sags. The authors presented a method for measuring and transforming the output voltage from QZS, enabling the use of a PI controller to control the voltage supplied to the DMC converter. The publication includes simulation and experimental studies comparing the operation of a PMSM motor powered by DMC and the proposed QZSDMC with voltage control. Simulation studies confirm the drive with QZSDMC resistance to voltage sags up to 80% of the rated value. Experimental studies demonstrate the correct operation of PMSM even with a power grid voltage amplitude equal to 40% of the rated value. [ABSTRACT FROM AUTHOR]

This paper presents a model predictive control (MPC) strategy to regulate output voltages in a multi-modular matrix converter topology for isolated loads. The converter system harnesses power from a six-phase permanent magnet synchronous generator (PMSG) to deliver sinusoidal voltages to a three-phase load, with LC filters positioned at the output of each MC module within the multi-modular scheme. The proposed MPC approach ensures that the output voltages remain within acceptable ranges of magnitude, phase, and frequency, even under load variations and system faults. This control strategy is particularly suitable for uninterruptible power supply systems, microgrids or other applications where voltage regulation is critical. Experimental studies validate the effectiveness of the control strategy under various load conditions, reference voltage changes, and simulated system fault scenarios. The results highlight the robustness and reliability of the proposed voltage control using the multi-modular matrix converter. [ABSTRACT FROM AUTHOR]

This study introduces a novel uninterruptible power supply (UPS) configuration that integrates active power filter (APF) capabilities within a single-phase matrix converter (SPMC) framework. Power disruptions, particularly affecting critical loads, can lead to substantial economic damages. Historically, conventional UPS systems utilized dual separate converters to function as a rectifier and an inverter, without incorporating any power factor correction (PFC) mechanisms. Such configurations suffered from diminished power density, compromised reliability, and spatial limitations. To address these issues, this research proposes an enhanced UPS design that incorporates APF features into the SPMC. The focus of this investigation is on the efficiency of alternating current (AC) to direct current (DC) conversion and the reverse process utilizing this advanced UPS model. The SPMC is selected to supplant the rectifier and inverter units traditionally employed in UPS architectures. A novel integrated switching strategy is formulated to facilitate the operation of the UPS in either rectifier (charging) or inverter (discharging) modes, contingent upon the operational state. The performance and efficacy of the devised circuit design and switching technique are substantiated through simulations conducted in MATLAB/Simulink 2019 and empirical evaluations using a test rig. The findings demonstrate that the voltage generated is sinusoidal and synchronized with the supply current, thereby minimizing the total harmonic distortion (THD) and enhancing both the power factor and the transition efficiency of the UPS system between its charging and discharging states. [ABSTRACT FROM AUTHOR]

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control 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.)

Efficient operation is a recommended factor in most of industrial applications. In this paper, an indirect matrix converter (IMC) topology is developed and proposed to substitute the classical (AC/DC/AC) three phase converter topologies; where the control strategy is frequently performed with a voltage source inverter (VSI). Large electrolytic capacitors are viewed as hazardous due to their short lifetime compared to ordinary capacitors and power switches, as well as their contribution to the total bulk and weight of the converter. Matrix converters may be the answer to getting rid of the capacitor, shrinking the converter, and improving its efficiency (MC). These advantages are offset by the fact that the (MC) calls for a tricky switching technique based on pulse width modulation, which is prone to commutation failure. The direct frequency conversion using the indirect matrix converter (IMC) with many advantages has appeared as an alternative to these conventional voltage inverters. This study investigates a field-oriented control (FOC) scheme for indirect matrix converter fed triple star induction motor (TSIM). After building the proposed IMC converter topology, an adequate fieldoriented control strategy-based space vector modulation (SVM) is proposed and adapted for the control of the triple star induction motor. The FOC technique guarantees flux and torque decoupling while ensuring good operation performance as required in many industrial applications. The obtained numerical simulation results show and confirm the effectiveness of this control scheme. [ABSTRACT FROM AUTHOR]

Problems related to voltage sags in distribution systems of electrical power add a number of challenges to the efficient performance of sensitive loads, hence the need for mitigation. The Dynamic Voltage Restorer (DVR) is a specialized device designed to counteract both low and high levels of voltage sags by being connected in series with the load. This paper introduces an application of a three-phase Matrix Converter for DVRs, which is capable of direct AC-AC power conversion without the need for an energy storage component. Motivated by the need for efficient and responsive voltage sag correction, a sliding mode controller with a Proportional-Integral sliding surface and hysteresis control is proposed. The traditional methods such as the real-coded genetic algorithm were considered but, these methods typically involve extended convergence times to optimize the PI gains of the Sliding Mode Control (SMC). To this effect, the Ant Colony Optimization (ACO) technique was used and generated the best values of PI gains of 6.87688 and 0.850851. The effectiveness of the SMC was tested under fault conditions and varying load scenarios using MATLAB simulation software, demonstrating satisfactory performance and stabilization at the onset of voltage sags. The DVR's performance, empowered by the Matrix Converter with the SMC framework, has been thoroughly analyzed, and the THD% was further scrutinized using the Fast Fourier Transform (FFT). This research confirms the Matrix Converter integrated with SMC as a robust solution for dynamic voltage restoration, providing a promising avenue for enhancing power quality in modern electrical distribution networks. [ABSTRACT FROM AUTHOR]

The effectiveness of application of matrix converter method at eddy current testing (ECT) is studied in the work. Advantages of eddy current matrix application are analyzed, which include improvement of sensitivity to small defects, shortening of the total control time and improvement of the probability of detection of various types of defects. To evaluate their effectiveness, a dimensionless coefficient is proposed, which takes into account the inspection time, the reliability of defect detection, and the sensitivity to defects of a certain size. Experimental studies on samples with artificially induced defects of different dimensions, types and orientation confirmed the rationality of application of this coefficient for testing parameter optimization, in order to improve defect detection in structural elements. The influence of various factors, such as condition of the surface, sensor configuration in the matrix and verification parameters on the productivity of ECT hardware and software with matrix converters was additionally analyzed. Obtained results will promote better understanding of the possibilities and limitations of matrix application in ECT of the components of transport, aviation and military equipment. It will allow optimizing the strategies of checking the controlled products, improving the reliability of defect detection and general maintenance practices in many industries. 16 Ref., 2 Tabl., 5 Fig. [ABSTRACT FROM AUTHOR]

Focused on addressing harmonic suppression in multiphase indirect matrix converters (IMCs), this study explores spread-spectrum modulation technology through ripple analysis calculations. We introduce a current ripple spread-spectrum modulation (CR-SSM) method tailored for multiphase IMC systems. In this approach, a 3 × 6-phase IMC is modeled as a two-port network, and a small-signal model of the output side is established. The transfer function is utilized to analyze the two-port network in the complex frequency domain (s-plane). The time-domain expression of the output current ripple is derived in vector form. Subsequently, the distribution of the output ripple and locus are determined based on specified constraints. The carrier frequency is dynamically adjusted online according to the specified ripple locus. Compared to classical periodic PWM methods, this approach offers a broader range of frequency variations and achieves a more uniform output spectrum. Furthermore, CR-SSM optimizes system efficiency and enhances spread-spectrum modulation. Experimental results demonstrate that this method effectively enhances the quality of input and output waveforms in multiphase IMC systems. [ABSTRACT FROM AUTHOR]

The active and reactive load changes have a significant impact on voltage and frequency. In this paper, in order to stabilize the microgrid (MG) against load variations in islanding mode, the active and reactive power of all distributed generators (DGs), including energy storage (battery), diesel generator, and micro-turbine, are controlled. The micro-turbine generator is connected to MG through a three-phase to three-phase matrix converter, and the droop control method is applied for controlling the voltage and frequency of MG. In addition, a method is introduced for voltage and frequency control of micro-turbines in the transition state from gridconnected mode to islanding mode. A novel switching strategy of the matrix converter is used for converting the high-frequency output voltage of the micro-turbine to the grid-side frequency of the utility system. Moreover, using the switching strategy, the low-order harmonics in the output current and voltage are not produced, and consequently, the size of the output filter would be reduced. In fact, the suggested control strategy is load-independent and has no frequency conversion restrictions. The proposed approach for voltage and frequency regulation demonstrates exceptional performance and favorable response across various load alteration scenarios. The suggested strategy is examined in several scenarios in the MG test systems, and the simulation results are addressed. [ABSTRACT FROM AUTHOR]

In this paper, a full nonlinear control of a variable-pitch wind system (VPWS) based on the doubly fed induction generator (DFIG) fed by a direct matrix converter (DMC) has been presented. In this context, The MPPT has been implemented using the third order sliding mode control (TOSMC) in order to ensure maximum power provided by the wind turbine on the one side, on the other side the pitch control has been implemented in order to limit the power extracted to its nominal value. Moreover, a TOSMC has been incorporated into the direct flied-oriented control (DFOC) to ensure high-performance control of the active and reactive power of DFIG. To examine the performance of the TOSMC, a comparative study was performed between this last type and the first and second order sliding mode controllers. The obtained results affirmed the high performance provided by the TOSMC compared to lower order sliding mode controllers. [ABSTRACT FROM AUTHOR]

This paper presents a novel multiphase hybrid matrix converter topology dedicated to grid-connected five-phase wind generation. The proposed converter, named Five-phase Ultra-Sparse Series Z-source Matrix Converter (FUSSZMC), aims to facilitate the integration of the five-phase wind turbine generators. This is done by taking into account the improvement of the injected power quality and allowing the fixed output converter voltage level to that of the grid, thanks to the use of the series Z-source, under the variable voltage magnitude of the wind turbine generator, which depends on the wind speed. The proposed space vector modulation as a control strategy for FUSSZMC was detailed, where it was demonstrated that a suitable use of both large and small current vectors improves the input current waveforms. The global model of the proposed system was tested by simulation under Matlab/Simpowersys environment. The obtained results demonstrate clearly the advantages of using FUSSZMC and its modulation strategie. These benefits includea good input and output current waveforms, as reflected by the obtained total harmonic distortion (THD) values, that fall within the range prescribed by international standards. Additionally, FUSSZMC is capable of operating with unity input power factor, regulating input voltages and improving the quality of injected power into the grid. [ABSTRACT FROM AUTHOR]

Neural networks have been used for a long time for image detection and recognition applications due to their ability and efficiency in complex problem solving. Several researchers have chosen to design and develop hardware accelerators for the convolution layer due to the large computational expense consumed by this layer. For that reason, a system that performs indirect GEMM convolution is implemented in a FPGA in this letter. Thus, the input data is segmented and distributed into acceleration modules in a parallel and distributed manner using the Network-on-Chip (NoC) paradigm, and a systolic array (SA) is implemented for the matrix multiplication operation as processing blocks within each NoC Node. Synthesis and performance results show that the implementation of this system presents better results compared to the state of the art in areas, such as acceleration factor, consumption of resources, latency, and operational frequency. [ABSTRACT FROM AUTHOR]

Hysteresis current controllers (HCCs) are extensively used in low-frequency power inverters and active power filters. Very little is known about their strengths and weaknesses when applied at supraharmonic frequencies. The major concern regarding the use of HCCs is their variable and uncontrollable switching frequencies. This results in difficulties in filter design, high switching losses, and the possibility of resonance conditions with power system elements. In this article, investigations are conducted on the application of HCCs in a hybrid filter for a 6 kHz matrix converter (MC)-coupled supraharmonic load. The effects of the MC-coupled load and VSC switches on the HCC's switching frequency are analyzed. A novel mathematical model for obtaining a fixed-frequency HCC is presented. The model is verified in open- and closed-loop HCC control configurations for a three-phase hybrid active power filter (HAPF). Fast Fourier transform (FFT) analysis of the supply current after the implementation of the novel HCC-HAPF showed 2.31% of the 50 Hz fundamental. The analysis is verified in a MATLAB/Simulink environment. [ABSTRACT FROM AUTHOR]

The three-phase matrix converter connected to the three-phase induction motor is studied in this paper. Typically, induction motors used in industries and automobiles operate on the electromagnetic induction principle. Due to its numerous benefits, including low cost and maintenance requirements, light weight, great efficiency, and others, a squirrel cage induction motor is employed in this situation. The speed of the induction motor may be changed by altering the voltage and frequency using a V/f control. A three-phase matrix converter is an automated AC-to-AC converter that uses a direct stage of conversion and bi-directional switches. Space vector modulation may be used to control the switches of a matrix converter, and by doing so, improve power factor. [ABSTRACT FROM AUTHOR]

Considering several space-vector modulation (SVM) methods, this study proposes SVM methods with carrier-based dipolar pulse width modulation (CBDPWM) for matrix converters. The switching patterns of well-known SVM methods are analyzed, and carrier-based modulation (CBM), which uses reference voltages selected from desired output voltages to generalize the PWM theory of two-level inverters, is developed for matrix converters. Moreover, the relationship between SVM and carrier-based dipolar modulation (CBDM) is revealed to generate the switching pattern of SVM methods. The experimental results confirm that arbitrary SVM methods, which require intensive calculations, can be easily realized by the CBDM by adding specified zero voltages and appropriately choosing a particular input phase as a reference.

The conventional topology of direct single‐to‐single‐phase matrix converter (SSMC) is widely adopted in industrial and power system‐related applications owing to its desired features. Current control methods in the literature either limit the voltage transfer ratio (VTR) or prohibit their utilization to drive inductive (RL) loads. In this study, we propose a novel control method that overcomes these limitations by enabling the SSMC to achieve relatively high VTRs while driving RL loads with negligible output voltage spikes and without current commutation problems. Further, the proposed control method improves the overall performance by reducing output voltage and source input current total harmonic distortion (THD) and offering soft‐switching at the commutation instances. The rigidity of the proposed control method over the counterpart methods in the literature is verified through simulation and experimental case studies over a wide range of synthesized output frequencies and modulation indexes. A 530‐W laboratory prototype is built for the experimental study. Results demonstrated the ability of the proposed method in enabling the SSMC to drive an RL load without current commutation issues and with mitigated output voltage spikes while achieving relatively high VTRs and suppressing the output voltage and source input current THD. [ABSTRACT FROM AUTHOR]

A matrix-integrated single-stage isolated MF/HF AC-AC/DC-AC/AC-DC converter topology stands out as an innovative concept, offering a multitude of advantages including minimal output current THDs, near UPF, 4Q operation, smooth BPF capability, and increased power density leading to the converter's enhanced efficiency, cost-effectiveness, and reliability. These characteristics render it an exemplary choice for RE-based power conversion applications. In fact, the matrix-integrated single-stage isolated MF/HF converters have witnessed an increased adoption of RE-based grid interconnection in recent years, specifically within solar PV, WECS, grid-tied offshore WF, and FC-based applications. RE sources produce variable and intermittent AC power by nature, further necessitating conversion to a stable and grid-compatible AC voltage and frequency. This is where MCs offer distinct advantages when contrasted with the conventional indirect dual-stage VSC-based rectifier–inverter topology. In this paper, a total of 22 matrix-integrated HF isolated converter topologies are broadly explored. Our study provides a comprehensive analysis and classification of matrix-integrated isolated single-stage MF/HF AC-AC converters, DC-AC inverters, and AC-DC rectifier topologies including modified topology architectures, control method, modulation techniques along with significant applications. Within this scope, the matrix-integrated converter topologies are categorized based on their architectures and other relevant subvariants. Our primary objective of this study is to impart a clear understanding of the overarching framework and principles of the matrix-integrated single-stage isolated MF/HF converter topologies and stimulate the creation of new topologies that cater to specific requirements for grid-interconnected systems. [ABSTRACT FROM AUTHOR]

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control 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.)

Integrating energy storage units (ESUs) into part of sub‐modules (SMs) enables the decoupling active power control for the modular multilevel matrix converter (M3C). The low frequency AC (LFAC) system based on M3C with symmetrically integrated energy storage (SI‐AM3C) can provide functions such as renewable power fluctuation smoothing and other power grid auxiliary services, which is attractive in engineering practices. This paper focuses on the design and control of SI‐AM3C. For the converter design, an evaluation method for the number of required active SMs (ASMs) is presented. On this basis, the influences of different system operating conditions on the ASM requirement are analyzed in case studies, and the effects of specific circulating injection strategies are also investigated. The control system targeted at decoupled AC side active power for SI‐AM3C is introduced. A modified inner‐arm capacitor voltage balance strategy is introduced to reduce the capacitor voltage deviation between ASMs and passive SMs (PSMs). The conclusions related to the presented estimation method and converter control strategy are verified by time‐domain simulations in PSCAD/EMTDC. [ABSTRACT FROM AUTHOR]

The Fractional Frequency Transmission System (FFTS) operates with low frequency to decrease the electrical length of AC transmission lines, consequently enhancing transmission capacity. The integration of renewable energy sources via FFTS will significantly impact power system planning. This paper presents a Fractional Frequency Transmission Expansion Planning (FF‐TEP) model, which considers the interaction between FFTS and the industrial‐frequency power grid. This model addresses the challenges posed by the integration of offshore wind power through FFTS, and takes several key factors into account, including the active power coupling of Modular Multilevel Matrix Converter (M3C), inverter capacity, and converter transformer capacity. To address the non‐convexity caused by AC power flow, this paper introduces a Genetic‐Particle Swarm Optimization algorithm (G‐PSO) with dynamic penalties tailored to the M3C structure. This approach incorporates both crossover and mutation operators from Genetic Algorithms (GA) into Particle Swarm Optimization (PSO). The penalty function dynamically adapts according to the M3C structure, resulting in improved global optimization while maintaining computational efficiency. The results of two case studies demonstrate that FFTS can significantly enhance transmission capacity while reducing cable charging power. This reduces investment costs and decreases voltage offset issues. [ABSTRACT FROM AUTHOR]

This paper proposes the utilisation of the direct matrix converter (DMC) to regulate the power transfer between a permanent magnet synchronous generator (PMSG) based wind energy conversion system (WECS) and the power grid. By connecting the PMSG at the output terminals of the DMC, control actions are simplified, implementation is facilitated since fewer sensors are required, and a WECS with a more compact structure is achieved because it is not necessary to use a transformer to compensate for the DMC voltage ratio. The DMC operation is controlled by the singular value decomposition (SVD) modulation technique and the four‐step switching strategy. For power regulation, an maximum power point tracking (MPPT) algorithm based on the wind turbine power curves technique is used in conjunction with the field‐oriented control technique and a proportional‐integral compensator. In the developed prototype of the WECS described, modulation, MPPT, four‐step current switching, control algorithms, and signal measurements are implemented on a single microcontroller unit. Finally, experimental results demonstrate the effectiveness of the proposed WECS in regulating the transfer of active and reactive power adequately and simultaneously with the power grid. [ABSTRACT FROM AUTHOR]

This study describes an indirect matrix converter (IMC) that uses symmetrical space vector pulse width modulation (SSVPWM) to feed two loads from a single DC link at a variable frequency. Output stage‐I is connected to the static load, while output stage‐II is connected to the PMSM for speed control. It is appropriate for drive systems with variable frequency, such as those seen in wind power generation and aviation. In recent years, significant studies on AC‐AC converters have been conducted due to the rising interest in electric cars and renewable energy. The performance of permanent magnet motors is better than that of other types of AC motors due to their superior performance and residual flux permanent magnets. Contrary to normal back‐to‐back power conversion systems, IMC does not necessitate the use of capacitors in the DC‐link, decoupled control between the two‐stages, a simple clamping circuit or zero current switching in the rectifier stage, allowing the system's volume to be reduced. It is investigated how well the two output stages of the proposed IMC perform. To illustrate the benefits of the suggested IMC design, an improved SSVPWM is employed, and MATLAB/SIMULINK‐based simulations were performed to validate the efficacy of the modulation mechanism. In addition, the real‐time implementation of the work was validated using a real‐time simulator, OPAL‐RT (OP4510). [ABSTRACT FROM AUTHOR]

A new direct torque control method for three-level direct matrix converter permanent magnet synchronous motor (TLDMC-PMSM) based on the modulation coefficient optimization method (MCOM) is proposed to address the problems of large torque chain pulsation, amplitude disorder and weak system robustness in matrix converter permanent magnet synchronous motor system (MC-PMSM) using direct torque control (DTC). In the paper, firstly, the principle of MC-PMSM-DTC system is described; secondly, the two-level MC is replaced by TLDMC, the speed loop is cascade spiral sliding mode control, the torque magnetic chain loop is super twisting sliding mode control-direct torque control to replace the traditional PI control, and the modulation coefficient optimal method is introduced to reduce the drawback of gradually increasing motor torque fluctuation, and then the accurate control of PMSM is realized; finally, the feasibility and superiority of the proposed method are verified by MATLAB/Simulink simulation software and hardware experiments. [ABSTRACT FROM AUTHOR]

An Innovative Modular multilevel matrix converter (M3C) is proposed with reduced number of switching device owing to the improved efficiency, reduced cost and minimizes the size. Offshore Low-Frequency AC (LFAC) transmissions are economical with greater reliability for short and intermediate distance transmissions. Similar to HVDC, it increases the transmission capacity and also distance can be increased in LFAC.M3C is proposed as frequency converters for LFAC transmissions which link AC systems operating at 16.7 and 50 Hz. The double αβ0 transform control technique has been the most often used approach for decoupling control of input, output and circulating currents in such applications. The performances of this work's proposed modular multilevel matrix converters are analysed using simulation in MATLAB/SIMULINK software. [ABSTRACT FROM AUTHOR]

In the process of hardware-in-the-loop simulations (HILs) of indirect matrix converters (IMCs), solving the mathematical models of complex multiswitching converter topologies has become a major problem. The conventional approach is to split the complex mathematical model into multiple serial subsystems; however, this inevitably produces delays in the simulation steps between different subsystems, leading to numerical oscillations. In this paper, the method of latency-free decoupling is adopted, which has no time-step delay between different subsystems, making each subsystem a parallel operation. This can improve the numerical stability of the simulations and can effectively reduce the step size of the real-time simulation and alleviate the problem of real-time simulation resource consumption. In this paper, we discuss in detail the modeling process of IMC hardware-in-the-loop simulations with Finite Control Set Model Predictive Control (FCS-MPC), and experimentally validate our method using the Speedgoat test platform, resulting in a simulation step size of less than 200 ns. The simulation results are compared with the results of Matlab's Simpower power system, which allows us to evaluate the accuracy of our model. [ABSTRACT FROM AUTHOR]

Recent research widely explored the quantization schemes on hardware. However, for recent accelerators only supporting 8 bits quantization, such as Google TPU, the lower-precision inputs, such as 1/2-bit quantized neural network models in FINN, need to extend the data width to meet the hardware interface requirements. This conversion influences communication and computing efficiency. To improve the flexibility and throughput of quantized multipliers, our work explores two novel reconfigurable multiplier designs that can repartition the number of input channels in runtime based on input precision and reconfigure the signed/unsigned multiplication modes. In this letter, we explored two novel runtime reconfigurable multi-precision multipliers based on the multiplier-tree and bit-serial multiplier architectures. We evaluated our designs by implementing a systolic array and single-layer neural network accelerator on the Ultra96 FPGA platform. The result shows the flexibility of our implementation and the high speedup for low-precision quantized multiplication working with a fixed data width of the hardware interface. [ABSTRACT FROM AUTHOR]

The multiphase matrix converter outperforms the conventional three-phase system with higher fault tolerance capability and higher power control competency. This paper discusses the direct control based on different possible switching combinations of a threephase to five-phase matrix converter (MC). The proposed control topology significantly reduces the switching commutations in a switching cycle when compared with its counterpart. The control is based on the modified space vector pulse width modulation (SVPWM) strategy. The proposed space vector scheme intelligently selects the voltage vectors to get the desired output characteristics with the least possible switching transitions in a switching cycle. Three possible cases exist in controlling space vectors based on their magnitude, the number of active switching vectors, and their commutations. The results for three different cases of SVPWM have been presented and compared. The total harmonic distortion (THD) obtained in the output is lower in case 2; however, it suffers from a higher commonmode voltage (CMV). The scheme has been successfully implemented and verified in hardware. [ABSTRACT FROM AUTHOR]

The goal of this work is to look at how to solve Barbashin equations using a mix of Volterra–Fredholm integro-differential equations and Volterra equations. For the first time, the 1D and 2D block-pulse functions are employed in a hybrid technique to solve this two-dimensional integral problem concurrently. We construct a new matrix called the converter operating matrix for this purpose. The Barbashin equation is reduced to a linear system that can be solved using well-known methods employing direct computing. The proposed method's convergence theorem is demonstrated under appropriate conditions. In addition, some numerical results are presented in the paper, which supports the strong theoretical properties of our approach. [ABSTRACT FROM AUTHOR]

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control 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 Electric Power Automation Equipment / Dianli Zidonghua Shebei is the property of Electric Power Automation Equipment Press 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 capacitor‐voltage‐balancing control scheme for an isolated medium‐voltage AC‐DC converter using level‐shifted pulse width modulation (PWM) control of a modular matrix converter (MMxC). The proposed isolated AC‐DC converter is composed of the primary MMxC with level‐shifted PWMcontrol, high‐frequency transformer, and secondary H‐bridge circuits. The high‐frequency transformer of the proposed circuit can be downsized because the level‐shifted PWM control scheme makes the rated frequency of the high‐frequency transformer equal to the switching‐frequency. The proposed capacitor‐voltage‐balancing control can compensate for the capacitor voltage imbalance of the MMxC using the positive‐sequence and negative‐sequence circulating‐currents with a power supply frequency and high‐frequency voltage. In the proposed control system, the three feedback control systems with DC control variables can be developed to compensate for the capacitor voltage imbalance. The effectiveness of the proposed capacitor‐voltage‐balancing control scheme and the control systems is verified by experiments using a 200 V, 5‐kW laboratory prototype. [ABSTRACT FROM AUTHOR]

The current paper is concerned with fuzzy controllers employing neural networks to implement control over power electronics systems committed to power quality improvement in a distribution grid. An optimization method technique for tuning fuzzy PI controller gains is introduced to improve a Hybrid Indirect Matrix Converter's control with a flying capacitor three-level inverter (HIMC), and it is connected via an RL filter to the power grid (PG). The harmonics are identified by an Artificial Neural Network (ANN). The effectiveness of this method is shown in the simulation results by MATLAB/Simulink (Simscap, simpower blocks). [ABSTRACT FROM AUTHOR]