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Accurately estimating the state-of-charge (SOC) of lithium-ion batteries (LIBs) in electric vehicles is a challenging task due to the complex dynamics of the battery and the varying operating conditions. To address this, this paper proposes the establishment of an Industrial Internet-of-Things (IIoT)-based digital twin (DT) through the Microsoft Azure services, incorporating components for data collection, time synchronization, processing, modeling, and decision visualization. Within this framework, the readily available measurements in the LIB module, including voltage, current, and operating temperature, are utilized, providing advanced information about the LIBs' SOC and facilitating accurate determination of the electric vehicle (EV) range. This proposed data-driven SOC-estimation-based DT framework was developed with a supervised voting ensemble regression machine learning (ML) approach using the Azure ML service. To facilitate a more comprehensive understanding of historical driving cycles and ensure the SOC-estimation-based DT framework is accurate, this study used three application programming interfaces (APIs), namely Google Directions API, Google Elevation API, and OpenWeatherMap API, to collect the data and information necessary for analyzing and interpreting historical driving patterns, for the reference EV model, which closely emulates the dynamics of a real-world battery electric vehicle (BEV). Notably, the findings demonstrate that the proposed strategy achieves a normalized root mean square error (NRMSE) of 1.1446 and 0.02385 through simulation and experimental studies, respectively. The study's results offer valuable insights that can inform further research on developing estimation and predictive maintenance systems for industrial applications. [ABSTRACT FROM AUTHOR]

Proper operation of the grid-tie transformerless converters under unbalanced and distorted conditions entails a precise detection of the frequency and fundamental component of the grid voltage. One of the main problems that could arise during the estimation of grid parameters is the existence of a DC offset generated from measurement and A/D conversion. This undesirable induced DC offset could appear as a part of the reference sinusoidal current of grid-tie converters. Although literature has proposed the use of an extended complex Kalman filter (ECKF) for the estimation of positive and negative sequence voltage components as a promising competitor to phase locked loops, mitigating the effect of possible DC offsets when a Kalman filter is employed remains scarce. This paper proposes a new extended complex Kalman filter to improve the filter stability for estimating the frequency and the fundamental positive and negative symmetrical components of the grid voltages, where DC offset, scaling error, and noise can successfully be rejected. The theoretical findings are experimentally validated. [ABSTRACT FROM AUTHOR]

Permanent magnet (PM) machines with fractional slot concentrated windings (FSCW) constitute a notably remarkable proposition for electric vehicles. Additionally, an integrated onboard battery charger (IOBC) provides another superiority as it exploits the components of the powertrain to charge the battery without any additional components. Interior permanent magnet (IPM) motor arises as a credible choice due to its high torque density, resulting from the high saliency ratio. The optimal design of an IPM motor has been extensively presented from different perspectives, but the optimal design of a motor employed for IOBC application for both propulsion and charging modes has not been studied extensively. In this paper, the design and optimization of a 12-slot/10-pole IPM motor with IOBC are studied under both propulsion and charging modes. A finite-element-based optimization with the aid of a genetic algorithm technique is proposed to obtain the optimal machine by maximizing the average torque and minimizing the torque ripple, core losses, and magnet size. [ABSTRACT FROM AUTHOR]

With the growing interest in owning electric vehicles due to increased environmental awareness and uncertain energy security together with the development of Li-ion batteries, quietness, and trouble-free operation, it is urgent to develop charging stations that are fast enough to supply the vehicles with energy conveniently, as in case of conventional petrol stations. The main reason that hinders the spread of fast charging stations is the installation cost, comprising the infrastructure and converter costs. In this article, a multiport DC-DC converter with differential power processing stages is proposed for Electric Vehicle (EV) fast charging stations, which results in a considerable reduction in the cost of using converters while achieving high efficiency. The proposed topology consists of two paths for the power flow (outer and inner loops) for EV battery charging with main and auxiliary DC-DC converters in the outer loop; all the ports are connected in series with the main supply, where the bulk power is being transferred. The main DC-DC converter injects a series voltage to control the power in the outer loop. The auxiliary DC-DC converters are rated at a fractional power that controls the partial power supplied to each port through the inner loops. Thanks to the fractional power processed by the auxiliary converter with the remaining power fed to the battery through the main converter, the proposed architecture enables simultaneous charging of multiple electric vehicles with better efficiency, lower cost, and the capability of providing a fault tolerance feature. A PWM control scheme for the converters to achieve bi-directional power flow in the partially rated DC-DC converters is discussed for the proposed system. Moreover, a practical down-scaled hardware prototype is designed to validate the functionality, control scheme, and effectiveness of the proposed topology in different case studies being investigated. The efficiency of the proposed converter is compared to the conventional configuration. [ABSTRACT FROM AUTHOR]

Due to simplicity, efficiency, and the ability to accommodate energy storage devices, DC distribution networks have been seen as an optimal alternative to AC distribution networks, especially aboard future electric ships. The emerging distribution DC system entails new control and management techniques. Therefore, an integrated DC power distribution network aboard an electric ship is selected as the case study in this paper. To meet the requirements of such a large-scale mobile power system, a multiport solid-state transformer (SST) based on silicon carbide (SiC) switches/MOSFETs is proposed. Thus, the system embodiment can significantly be reduced. Moreover, at the DC distribution level, a high penetration of renewable generation with energy storage is allowed and a six-phase asymmetrical induction machine (IM) can directly be integrated. Simulations have been conducted based on a 2 MW shipboard distribution network. The effects of the propulsion system dynamics on the SST are highlighted as well. Finally, a 2 kW lab-scale prototype has been implemented to validate the theoretical findings. [ABSTRACT FROM AUTHOR]

This article presents the operation of onboard integrated battery chargers tied to a nine-phase EV-drive train, shedding light on the charging performance during the postfault operation, when one or more faulty inverter legs are disconnected. The objective in that case is to ensure balanced grid currents, while maintaining minimum machine losses at zero average torque production. The proposed concept requires a minimalistic change from a control structure perspective to switch between the pre- and postfault cases. Limitations and fault cases are discussed and corroborated with experimental tests on a 1.5-kW prototype.The derived concept is parameter independent and applicable to nine-phase drives, irrespective of the type of rotor used. [ABSTRACT FROM AUTHOR]

This paper studies the postfault control of a nine-phase six-terminal induction machine (IM) during single open-line fault, which was recently proposed for high-power medium-voltage applications as a promising alternative to conventional six-phase IMs. The required optimal reference currents to provide prefault loading conditions under one-line open are derived using the two most common optimization criteria employed in multiphase drives, namely, maximum torque and minimum loss modes. A postfault controller, based on conventional decoupling Clarke's transformation, is then used to ensure the same controller structure under all conditions. Consequently, the machine characteristic curves, achievable torque, and stator copper losses under these different modes are compared. A comparison with a conventional asymmetrical six-phase winding is also given. A 1.5-Hp prototype IM is used for experimental verification. [ABSTRACT FROM PUBLISHER]

AC-side compensation for current source converters using a shunt active power filter (SAPF) is affected by delays introduced into the reference signals and/or the actual injected current. The delays should be identified and compensated to eliminate distortion from the supply current extracted from the point of common coupling, such that the total harmonic distortion complies with standards. An improved distortion factor is achieved if the delay for each harmonic order is considered individually. This paper introduces an open-loop control strategy for the SAPF, which is capable of mitigating specific and predetermined harmonic orders and consequently achieves low total harmonic distortion. The delays are minimized or eliminated when extracting the reference current and controlling the filter current. The control technique is applied on a medium-voltage asymmetrically controlled 12-pulse ac to dc current source converter, which follows a specific power locus with the SAPF connected via taps on the star connected secondary winding of the front end transformer, to compensate the mains current dominant harmonics (5th, 7th, 11th, and 13th). Medium voltage simulation results are verified experimentally using a scaled prototype. [ABSTRACT FROM PUBLISHER]

In this paper, compensation of the dc-side voltage harmonics of a medium-voltage (MV) 12-pulse ac/dc converter is achieved using a series active power filter (APF). The output voltage harmonics are dependent on the converter firing delay angles and, consequently, on the specific power locus followed by the ac/dc converter. This power locus ensures minimum fifth and seventh harmonics (total rms) in the input current which provides minimum input current total harmonic distortion when the reactive power is less than 0.5 p.u. The series APF is connected between the load and the converter output via a magnetic amplifier to eliminate the dc current from the APF inverter, thus reducing inverter losses. Voltage harmonic compensation using a series APF, with and without a magnetic amplifier, is examined with both resistive and inductive loads. The simulation results for compensating a 3.3-kV MV 12-pulse converter system are experimentally verified using a scaled prototype 12-pulse converter with a series APF. [ABSTRACT FROM PUBLISHER]

Electric vehicle charging technology has recently witnessed massive developments due to its significant role in the ever-growing number of electric vehicles on the market. The integrated on-board charger technology (IOBC) represents an effective and attractive solution to reduce EV size, cost, and weight. IOBC technology employs propulsion components, such as the motor and its converter, in the charging process. The main objective of IOBC is to achieve the maximum charging current with zero average/pulsating torque so that mechanical interlocking can be dispensed. Recently, some of the IOBC topologies have adopted machines with six-phase stators to exploit the many advantages of multiphase-based systems. This paper investigates the effect of the winding design, namely, chorded or un-chorded designs, as well as the winding configuration, namely, dual three-phase, asymmetrical, or symmetrical winding configurations, on the current quality of a six-phase-based non-isolated IOBC. The relation between the winding design and the induced low order harmonics in the charging current is first clarified. The required current controller structure is then proposed, which ensures balanced grid line currents with high quality, under either healthy or one-phase fault conditions. Finally, a comparative study between all available designs with the proposed current controller is carried out to validate the theoretical findings. [ABSTRACT FROM AUTHOR]

Various applications, like in underground mines and oil and gas industries, require remote operation of vector-controlled medium-voltage variable speed drives via a long motor feeder. The use of voltage source inverters in such cases leads to motor overvoltage and harmonic quality problems. The current source inverter (CSI) is ideally matched to these applications because of its motor-friendly voltage output. Speed sensorless operation is mandatory due to the long motor feeder. Although the model reference adaptive system (MRAS) is a powerful and proven speed estimation tool, its implementation in long motor feeder drives faces many challenges. Among them, and addressed in this paper, are inherent dc offset in its stator model, the need for actual motor voltage and current values, and oscillations in the estimated speed due to errors in the motor current measurement signals. In this paper, a sensorless CSI vector-controlled drive, suitable for long motor feeder applications, is studied. Improved speed estimation is achieved by proposing 1) a modified dc-offset eliminator for an MRAS speed estimation and 2) a compensation technique for motor current's measurement errors. Intensive experimental results, for a low-voltage scaled model, along with simulations validate the effectiveness of the proposed technique. [ABSTRACT FROM AUTHOR]

Medium-voltage (MV) drives are generally based on either voltage-source inverters or current-source inverters (CSIs). CSIs feature simple topology, motor-friendly waveforms, power reversal capability, and short-circuit-proof protection; hence, they are widely used as high-power MV drives. Direct vector control (DVC) CSI drives ensure improved performance by decoupled control of the machine flux and torque using two independent control loops. Despite the excellent performance of DVC, this scheme faces practical challenges, like dc offset in the stator model and machine parameter dependence. Conventional indirect vector control (IVC) CSI drives are known for reduced computational burden and less machine dependence. However, conventional-IVC CSI drives exhibit poor dynamic response and transient field misorientation due to the absence of a dedicated flux control loop. In this paper, a modified IVC technique is proposed featuring superior decoupling and field orientation using only two extra proportional–integral current controllers with additional motor current feedback signals. The proposed-technique effectiveness is examined experimentally, on a scaled low-voltage prototype, as well as using simulation results. [ABSTRACT FROM AUTHOR]

Active power filter (APF) performance is affected by the system delay introduced in the reference signals and/or the actual injected current. This study introduces an artificial intelligent-based technique using a neural network control strategy for a shunt APF. The proposed system is capable of mitigating specific harmonic orders and consequently achieves low harmonic factor and reduced current total harmonic distortion (THD). In addition, the delay time introduced when extracting the harmonic reference current and when controlling the filter current is minimised. The control technique presented in this study is assessed on a medium voltage 6-pulse current source converter where the mains current dominant harmonics (5th, 7th, 11th and 13th) are compensated. The proposed system is simulated using MATLAB/SIMULINK. A prototype system is used to experimentally validate the proposed APF performance. [ABSTRACT FROM AUTHOR]

Permanent magnet machines (PMs) equipped with fractional slot concentrated windings (FSCWs) have been preferably proposed for electric vehicle (EV) applications. Moreover, integrated on-board battery chargers (OBCs), which employ the powertrain elements in the charging process, promote the zero-emission future envisaged for transportation through the transition to EVs. Based on the available literature, the employed machine, as well as the adopted winding configuration, highly affects the performance of the integrated OBC. However, the optimal design of the FSCW-based PM machine in the charging mode of operation has not been conceived thus far. In this paper, the design and multi-objective optimization of an asymmetrical 12-slot/10-pole integrated OBC based on the efficient magnetic equivalent circuit (MEC) approach are presented, shedding light on machine performance during charging mode. An 'initial' surface-mounted PM (SPM) machine is first designed based on the magnetic equivalent circuit (MEC) model. Afterwards, a multi-objective genetic algorithm is utilized to define the optimal machine parameters. Finally, the optimal machine is compared to the 'initial' design using finite element (FE) simulations in order to validate the proposed optimization approach and to highlight the performance superiority of the optimal machine over its initial counterpart. [ABSTRACT FROM AUTHOR]

Objective: Evaluate the value of high‐resolution ultrasonography (HRUS) in diagnosis of various laryngeal lesions. Method: A prospective study done from March 2010 to July 2011 on 66 patients suffering from voice changes, pre‐examined by rigid endoscopy and diagnosed to have a laryngeal lesion, and 32 volunteers composed the control group. All 98 persons (patients and control groups) were examined by HRUS. Results: HRUS was helpful in describing various laryngeal lesions as vocal cord nodules (13) 19.6%, vocal cord polyps (17) 25.7%, epiglottal enlargement (2) 3.03%, and vocal cord mass (6) 9.09%. It was highly significant in diagnosis of early subglottic lesions—(10) 15.2%—that were missed by rigid endoscopy. Also, vocal cords mobility can be demonstrated by HRUS. However, interarytenoid edema (18) 27.3% was difficult to detect. Conclusion: Rigid endoscopy is difficult to diagnose laryngeal lesions in patients with sensitive gag reflex, neck or jaw diseases, and stridor and in infants. HRUS is an alternative method in diagnosis of some laryngeal lesions in these patients, and it is superior in the diagnosis of small subglottic lesions. [ABSTRACT FROM AUTHOR]