• Energy Research

This article presents a new modulation technique called three-dimensional sigma–delta (3D-ΣΔ) modulation for high-frequency three-leg four-wire voltage source converters (VSCs) that use wide-bandgap (WBG) semiconductors. These WBG devices allow for the use of high switching frequencies with a greater efficiency than silicon devices. The proposed 3D-ΣΔ technique enables operation at a variable switching frequency, resulting in a significant reduction in switching losses compared to classical pulse-width modulation (PWM) techniques. Moreover, the 3D-ΣΔ technique uses a fast-processing 3D quantiser that simplifies implementation and considerably reduces computational costs. The behaviour of the 3D-ΣΔ modulation is analysed using MATLAB/Simulink and PLECS. The experimental results performed on an active power filter that uses silicon carbide (SiC) MOSFETs demonstrate an improvement in converter efficiency compared to the conventional SPWM technique. Additionally, the experimental results show how 3D-ΣΔ allows for the compensation of harmonics and homopolar currents, thereby balancing the electrical grid currents. The experiments also show that the proposed 3D-ΣΔ modulation outperforms an SPWM technique in terms of power quality, since the former achieves a larger reduction in the harmonic content of the power grid. In conclusion, the proposed modulation technique is an attractive option for improving the performance of four-wire converters in active power filter applications.

The power quality of electrical grids is becoming an important issue worldwide. The electrical grid has to deliver sinusoidal voltages and currents without frequency or amplitude variations. However, the connection of non-linear loads generates harmonics that degrade the grid quality. The presence of harmonics in the load currents has many negative consequences and can distort the voltage waveform at the point of common coupling (PCC). Thus, it is essential to mitigate the harmonics in order to maintain a suitable grid quality. This is a shared responsibility between energy suppliers, manufacturers of electric and electronic equipment, and users. In this context, this work presents, for each stakeholder, a comprehensive analysis of their responsibilities and the standards that they should meet. Additionally, this paper reviews the most common types of filters used to comply with the applicable standards in industrial applications. Finally, in order to prove that active power filters allow maintaining good power quality in all types of grid, commercially available active power filters were installed in three different grids contexts: an office building, a factory, and a stadium with a large number of LEDs. The experimental results obtained were used to evaluate the impact of active filters on grid quality. This review would help users to overcome their grid distortion problems.

© 2023 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. This paper proposes and studies different sigma-delta () modulation strategies for obtaining a constant common-mode voltage (CMV) by eliminating the CMV level transitions in a five-phase voltage source inverter (VSI). These techniques are based on choosing vectors that generate a constant CMV with values of 0.1Vdc or 0.1Vdc. Because of the high-switching frequencies used with wide-bandgap semiconductors, pulse-width modulation (PWM) techniques continually generate high dv/dt values. Therefore, the proposal to combine a modulation strategy with vector selections achieves: 1) a constant CMV level due to the elimination of its level transitions; 2) a reduction in conducted electromagnetic interference; and 3) a high-efficiency converter operation. The average number of switching per transistor of the VSI is analyzed using the results from Matlab/Simulink and PLECS simulations. Experimental results are obtained by applying the proposed modulation strategies on a VSI with silicon carbide (SiC) MOSFETs. The results demonstrate the achievement of the aforementioned features. This work was supported in part by the Ministerio de Ciencia, Innovacion y Universidades of Spain within ´ the TRA2016-80472-R and PID2019-111420RB-I00 projects, the CONACYT of Mexico under scholarship 496458, Secre- ´ taria d’Universitats i Recerca del Departament d’Empresa i Coneixement de la Generalitat de Catalunya. Peer Reviewed

Permanent Magnet Synchronous Machines (PMSMs) have several advantages, such as high ef¿ciency and low volume and weight, which make them attractive for aerospace applications and high performance servo drives. Matrix Converters (MCs) are an all-silicon alternative, with no bulky reactive elements, to the standard voltage source inverter. The most common control technique for such PMSM MC-fed drives is the so-called Field-Oriented Control (FOC), which requires the permanent magnet ¿ux position to achieve high dynamic performance. Encoders or resolvers are the most common sensing devices used for such a purpose, which not only increases the total cost of the PMSM drive but also adds extra electronics and cabling that may cause failures. This paper investigates and proposes an all range (from zero to full) speed hybrid sensorless FOC. The novelty of this paper relies on the use of a hybrid sensorless four quadrant FOC that averages the needed angle estimation from a model based angle estimator and a voltage pulse test injection angle estimator when feeding the PMSM with an MC instead of a standard voltage source inverter. Speed reversal and load impact simulation results are included, fully supporting the claims made in this paper Peer Reviewed

This paper presents two different variable-speed control strategies to obtain the maximum power from wind turbines (WT). The two control strategies are composed by three regulators, which may be based on linear or nonlinear controllers. The first control strategy is composed of three standard proportional-integral (PI) regulators. The PI controllers are tuned for a specific operation mode. However, since the system is nonlinear, for different operating conditions, the values of the PI parameters may not be optimal. The second control approach includes a nonlinear (fuzzy) controller to compensate for the nonlinearity of the WT, to achieve improved speed performance under different operating points. The proposed control strategy uses a fuzzy controller and two standard PIs. The results show that in most cases the fuzzy controller obtains superior performance to that of the standard PI-based solution.

This paper analyzes and compares different control tuning strategies for a variable speed wind energy conversion system (WECS) based on a permanent-magnet synchronous generator (PMSG). The aerodynamics of the wind turbine (WT) and a PMSG have been modeled. The control strategy used in this research is composed of three regulators, which may be based on either linear or nonlinear controllers. In this analysis, proportional-integral (PI) linear controllers have been used. Two different tuning strategies are analyzed and compared. The main goal is to enhance the overall performance by achieving a low sensitivity to disturbances and minimal overshoot under variable operating conditions. Finally, the results have been verified by an experimental WECS laboratory prototype Peer Reviewed

Multiphase systems provides benefits compared to three-phase systems, such as improved torque per ampere, high power density, better fault tolerance, lower current per phase (due to power-splitting among a higher number of phases), and lower torque ripple, among others. Depending on the application, the system must meet determined requirements, such as the presence of harmonic content, power losses, and common-mode voltage (CMV) generation. This paper presents a comparative analysis of space vector modulation (SVM) techniques applied to a five-phase voltage source inverter with SiC switches to provide an overview of their performance. The performance of five-phase 2L SVPWM (space vector pulse width modulation), 2L+2M SVPWM, 4L SVPWM techniques, and their discontinuous versions, are analyzed by focusing on harmonic content, power losses, and CMV generation using SiC semiconductor devices. Matlab/Simulink and PLECS simulations are performed to achieve the above mentioned goal. The use of different techniques allows (1) reducing the harmonic distortion when 2L+2M SVPWM and 4L SVPWM are applied, and (2) the switching sequence of the modulation techniques can influence the switching losses. Therefore, the use of SiC switches reduces the switching losses. (3) However, CMV dv/dt increases. Therefore, it is possible to minimize the effects of the CMV dv/dt and amplitude by choosing the adequate technique.