Presents the table of contents for this issue of the publication.

Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.

The space vector pulsewidth modulation (SVPWM) techniques enhance the performance of multilevel multiphase inverters. With multilevel (three-phase) inverters and with (two-level) multiphase inverters, it is widely accepted that the typical SVPWM strategies have an equivalent carrier-based pulsewidth modulation (CBPWM) counterpart, which produces identical results. However, the conclusions reached in

In this article, an enhanced five-segment space vector modulation (SVM) approach is proposed for a five-phase current source converter (CSC) to simultaneously reduce its output current harmonics and common-mode voltage (CMV). To realize proper output current harmonics mitigation, the reference current vector is synthesized by adjacent four large vectors and one zero vector in the fundamental plane

This article investigates the influence of two nonideal factors on zero-crossing-point-detection-based sensorless control of high-speed brushless dc (BLDC) motor, i.e., asymmetric machine parameters and the resistance tolerance of back electromotive force (EMF) measurement circuit. Influenced by the machine parameter asymmetry, the back EMF envelopes will shift horizontally from its ideal position

This article proposes a novel hybrid-magnetic-circuit variable flux memory machine (HMC-VFMM) by combining series and parallel hybrid magnet structures. Thus, the synergies of wide flux regulation range in parallel type and excellent on-load demagnetization withstand capability in series type can be simultaneously obtained with the proposed HMC design. Meanwhile, two sets of the permanent magnets (PMs)

Gearless and small motors operating at speeds above 10 000 rpm are finding many applications nowadays. Axial flux permanent magnet (AFPM) motors are compact and lightweight compared to radial flux motors and hence, are considered for various high-speed applications. Eliminating the stator core minimizes the associated high-frequency losses, and hence, coreless AFPM motor can be an option for high-speed

In this article, the flux reversal permanent magnet (FRPM) machine with toroidal windings is presented and analyzed with reference to conventional concentrated windings. First, the influence of rotor pole numbers on FRPM machines with conventional concentrated windings is investigated. It is found that although the 12/13 stator slot/rotor pole FRPM machine has a high back electromotive force, the pitch

The relationship between the stator and rotor leakage reactance of the induction machine (IM) according to IEEE Std 112 is assumed to be constant under all operating conditions. However, this is not substantially accurate during severe transients such as the direct online startup and loading conditions of a three-phase induction motor. The leakage reactance of the machine can vary widely during severe

This article presents a new field-modulation double-stator electrical-excitation synchronous machine (FM-DSEESM) and analyzes its harmonic components of double-layer air gap magnetic field. The key is that both the types and sources of various harmonic-components of air gap magnetic field are derived by taking into account the permeance components of both inner and outer stator teeth and modulation-ring

This article proposes a new asymmetric neutral-point diode-clamped (NPC) multilevel converter for a four-phase switched reluctance motor drive. The inbuilt NPC clamping capacitors are used for both voltage level clamping and also as dc rail voltage-boosting capacitors to increase the output power of the motor, particularly for high-speed electric vehicle applications. The new converter allows regenerative

The requirement for electrical machines with high power/torque density has stimulated the development of high efficient cooling systems to dissipate the heat within the machines. This article presents a new water cooling topology for thermal management of a permanent-magnet synchronous machine (PMSM) with concentrated windings. The advanced cooling configuration consists of several water cold plates

In this article, an airgap-harmonic-orientated design method is proposed, where the airgap harmonics are newly acted as the effective bridge between the three key elements of permanent magnet sources, modulators, or armature windings and the motor performances. In the proposed design method, the airgap harmonics play couple roles of design objectives and variables, which are not only served as the

Eddy current analysis is a key issue for large turbine generators. The finite-element method (FEM) is a computational tool for obtaining the electromagnetic characteristics of electrical machines. In this article, we propose a computer model of the eddy current losses of metal fasteners in the rotor slots of a large turbine generator. The electromagnetic properties of the rotor fasteners and the outer

For the high-speed permanent magnet synchronous motors (HSPMSMs), their magnetic fields are more complicated with the rotating magnetization and harmonics considered. Furthermore, there are interaction effects on motor iron loss from high frequency, temperature, and compressive stress. In order to obtain the accurate HSPMSM iron loss calculation model, different iron loss models are proposed, in this

In this article, the permanent-magnet (PM) eddy current loss in a four-phase fault-tolerant flux-switching PM (FT-FSPM) machine is investigated from the perspective of air-gap magnetic field modulation. It can be found that the PM eddy current loss in FT-FSPM machines results from the relative motion between air-gap field space harmonics and PMs. Some effective working harmonics produce the major PM

Digital power management systems allow power converters to operate with multiple changes in voltage reference. This asks for a new paradigm that shifts from achieving faster response to achieving best efficiency during multiple transients, with transient being eventually time constrained. State-space-based design of the control system fits perfectly this goal, since it is a time-domain design tool

In this article, a new nonisolated high step-up quasi Z-source (QZS) dc–dc converter with coupled inductor techniques is presented, which is suitable for renewable applications. The main advantages of the proposed topology are continuous input current, common ground between load and input dc source, low normalized voltage stress on the semiconductors (switch/diodes), and low total voltage stress on

This article proposes a self-balanced cascaded H-bridge multilevel inverter with a binary asymmetric ratio. The inverter uses only one dc source per phase that will feed the H-bridge with the highest dc-link voltage (called main bridge). The dc links of all other H-bridges (called auxiliary bridges) are formed by floating capacitors. Floating capacitors converge to the corresponding steady-state voltages

This article proposes two magnetic integrated filters, called ${\mathsf \Gamma}$-source and Flipped-${\mathsf \Gamma}$-source with the advantage of better magnetic circuit utilization. Therefore, the number of required magnetic cores and the total size of inductive elements are reduced compared to the other high-order filters, such as the LCL and the LLCL . Also, the total windings copper weight as

This article addresses a single-stage bidirectional step-up inverter designed from the integration of a differential boost inverter and switched-capacitor (SC) cells. The conventional boost inverter, even being a step-up topology, presents a gain limitation due to losses, and therefore, does not fully attend the step-up specifications. The insertion of SC multiplier cells into it allows increasing

The LLC resonant converters commonly adopt frequency modulation (FM) or combination of FM with phase-shift modulation to regulate its output voltage. However, in these control schemes, a variable switching frequency range is required, which makes the magnetic components design complicated. Therefore, in this article, magnetic control (or variable inductor control) is adopted to make the converter operating

A three-winding coupled inductor, arranged as a Y -source network, has been used for voltage boosting with a standard inverter bridge and no other active switches. However, its maximum modulation and boost duty ratios are correlated with an increase of one maximum necessitating the reduction of the other. Its voltage quality and dc-bus utilization will hence deteriorate greatly at high gain. Moreover

A large-capacity harmonic current widely exists in low-voltage distribution networks, which seriously affects the operation reliability and the efficiency of power system and related equipment. Due to its excellent controllability and dynamic response performance, the full-controlled semiconductor-device-based multimodular shunt active power filter is considered as the optimal choice to compensate

In meshed high voltage direct current grids, the current of each line cannot be controlled independently, since it depends on the resistances between nodes. Additional devices, such as current flow controllers (CFCs), may be needed to avoid bottlenecks or line overloads. This work presents a multiport dc–dc-based CFC topology to be connected to $n$ lines with unidirectional current flows. The device

In this article, a hybrid interleaved connecting boost converter (HIBC) with a wide step-up regulation range is proposed, which is suitable for the low-voltage distributed generation applications. In the input of the HIBC, the primary windings of the double-coupled inductors are interleaved parallel connection, inheriting shared current and reduced current ripples. Then, the lossless passive clamped

For the virtual synchronous generator (VSG) connected to the distorted grid, it is difficult to address the distorted grid current issue by the conventional harmonic suppression methods. To address this issue, in this article, we propose an impedance-based harmonic current distortion suppression method without closed-loop control to improve the adaptability of VSG connected to the distorted grid, mainly

In this article, a modified hybrid dc breaker and a half-bridge modular multilevel converter (MMC) are employed to interrupt the dc fault current in a high-voltage direct current transmission system. In the hybrid dc breaker, parallel to the main branch, a series connection of an energy-absorbing capacitor and a Thyristor stack is employed. When a dc fault current is recognized, the Thyristor stack

The voltage–frequency coupled transient stability and risk assessment issues of weak grid-connected large-scale renewable energy plants (REPs) during low voltage ride through (LVRT) have received little attention to date. The shape and mechanism of voltage–frequency coupled transient instability during LVRT are investigated in detail by the voltage-vector-triangle graphic (VTG) method utilized in this

A low-voltage microgrid is naturally three-phase unbalance due to the connection of unbalanced loads. Voltage unbalance compensation (VUC) strategies of inverters have been proposed to compensate the voltage unbalance on the point of common coupling. However, the small-signal analysis of these VUC strategies has not been investigated in a microgrid with multiple inverters, which is due to the difficulty

A coupled inductor-based buck–boost type single phase transformerless grid connected photo voltaic inverter which has the ability to extract maximum power simultaneously from two serially connected subarrays is proposed in this article. The series connection of the two subarrays, and the buck–boost nature of the inverter result in reduction of the number of modules which are connected in series in

An active method for detection of islanded operation in a microgrid integrated with one or more inverters operating in parallel is proposed in this article. The method identifies the islanded mode by introducing a predefined pattern of small periodic step changes in the active power injected. Islanding is said to have occurred if the ratio of d -axis component of voltage at the point of common coupling

The helical microstructure has been widely applied to various industries, including the mechanical manufacture, electronics, and biomedical engineering. Due to the miniature size of the helical microstructure, the low manufacture precision will highly degrade its working performance. Although current manufacture methods can realize its fabrication with relatively high accuracy, the used material is

Tray indexing driven by timing belt actuator is widely used in the industry, where high-precision profile tracking is essential to guarantee good production quality. To avoid humming sound and chip dislodged, an autonomous S-curve trajectory is used as the reference profile and the jerk resulting from the control input chattering needs to be well controlled. To implement the optimal tracking control

This article presents a novel method to generate a trajectory for a two-wheeled mobile robot moving in an uncertain environment where only a few way-points are available to reach a nearby target state. The proposed method interpolates way-points by the combination of a straight line and a fifth-order Bézier curve along which the curvature varies continuously. In addition, a method to generate the associated

Hysteresis in piezoelectric actuators (PEAs) causes significant position errors and limits the application of PEAs. Compensating hysteresis via inverse models is one of the most popular approaches to reduce its effects. However, the construction of an accurate model is very challenging since hysteresis is coupled with creep and high-order dynamics, and hysteresis properties are also affected by operating

Modern robots are increasingly being designed to collaborate with human, and the safety of human-robot interaction has become more significant than ever. Series elastic actuator (SEA) is a potential actuator system in force control for various robotic applications with inherent safe property. However, achieving the good performances of SEA torque control especially with unknown load-side dynamics is

The insulation material applied on the stator windings of automotive electric machines are susceptible to the excessive temperature rise. Typically, several thermocouples are embedded in the end-winding and the active winding in the slot to detect the peak temperatures in real-time to avoid thermal damage and adjust cooling. However, in the slot windings, the uneven distribution of power loss will

This article proposes a general design method for dual-stator field modulation machines (DSFMMs) that can be separated into two field modulation machine (FMM) portions sharing the key components with each other. The existing permanent-magnet synchronous machines and FMMs can be categorized into R/S types, where R denotes the part that can generate the rotating magnetic field, and S represents the stationary

In this article, we investigate the tuning problem of digital proportional-integral-derivative (PID) parameters for a dc motor controlled via the controller area network (CAN). First, the model of the dc motor is presented with its parameters being identified with experimental data. By studying the CAN network characteristics, we obtain the CAN-induced delays related to the load rate and the priorities

In this article, a continuous terminal sliding mode control algorithm is proposed for servo motor systems. A novel full-order terminal sliding mode surface is proposed based on the bilimit homogeneous property, such that the sliding motion is finite-time stable independent of the system's initial condition. A new continuous terminal sliding mode control algorithm is proposed to guarantee that the system

This article introduces the analytic modeling optimal control method in details, aiming at solving special control problems of pulsed power supply for heavy-ion accelerator magnet. These problems include variable waveform, high speed, high precision, and wide dynamic range. To meet these requirements, this method has been proposed as a new choice. The mathematical model is analytic function, which

Acoustic behavior of electric drives is an important factor for their application in areas where humans expect certain comfort, such as in electric vehicles. The main problem addressed in this article is high tonality of noise emitted by conventional pulsewidth modulation (PWM) controlled drives. We propose to use an explicit model of the transfer function from the electric variables to the sound pressure

This article addresses the problem of state estimation of controlled affine nonlinear systems in the presence of disturbances and uncertainties in the state equation. The proposed algorithm synthesizes a full-order observer, which joins the concepts of sliding mode observer and the ultimate uniform bounded stability. For this, on the state equation of the system, a transformation is used to disjoin

Deep convolutional neural networks have recently made a considerable achievement in the single-image superresolution (SISR) problem. Most CNN architectures for SISR incorporate long or short connections to integrate features, and treat them equally. However, they neglect the discrimination of features, and consequently, achieving relatively poor performance. To address this problem, in this article

This article presents a novel method of dealing with disturbances and control saturation in the framework of discrete-time sliding mode control (DSMC). A DSMC with decoupled disturbance compensator (DDC) was developed for SMC to recover the loss of stability in the discrete-time domain. However, windup phenomena occur in both the switching function and the disturbance estimate when control saturation

Owing to the high-frequency and high-power requirements for communication integrated circuits (ICs) in today's rapid development of electronic technology, the intensity of electromagnetic field from the ICs can be significant. This article shows a failure due to this enhanced electromagnetic field in a gallium nitride based high electron mobility transistor high-frequency power amplifier. Inputs were

In hybrid dynamical systems, degradation evolution of components depends on the operating modes of the system, which are activated by discrete events. In a hybrid system's dynamics, some parameter degradations may not be observable from the measured variables in every state of the discrete components. Thus, the degradation model identifications (DMI) for hybrid components’ parameters are difficult

This article proposes an advanced technique for condition assessment of outdoor insulators based on its surface leakage current through employing detrended fluctuation analysis (DFA). Analysis of surface leakage current of in-service insulator can be useful for assessing its surface condition. In the proposed technique, a tracker signal has been developed based on the fundamental component of surface

In dynamic complex environments, the degradation of structure systems is generally caused not by a single factor but by multiple ones, and the process is subject to a high level of uncertainty. This article contributes a hybrid physics-model-based and data-driven remaining useful life (RUL) estimation methodology of structure systems considering the influence of multiple causes by using dynamic Bayesian

A common source of defects in manufacturing miniature printed circuits boards (PCBs) is the attachment of silicon die or other wire bondable components on a liquid-crystal polymer substrate. Typically, a conductive glue is dispensed prior to attachment with defects caused either by insufficient or excessive glue. The current practice in electronics industry is to examine the deposited glue by a human

Numerical and analytical methods are two methods to evaluate the performance of electrical machines. This article provides a comparison between numerical and analytical methods. Electrical machine software typically uses numerical methods to solve the electromagnetic equations. On the other hand, analytical methods are faster and more intuitive. A general analytical modeling technique to evaluate the

This article focuses on the design of a magnetic sensor (MS) in position detection of a permanent magnet linear motor (PMLM). The MS is composed of a hall-effect-integrated-circuit and magnetic materials, and it is well known as a contactless sensor with a simple structure, and low cost. As a result, it is preferred for precise linear positioning applications. The work presented in this article consists

Existing video summarization approaches mainly concentrate on the sequential or structural characteristic of video data. However, they do not pay enough attention to the video summarization task itself. In this article, we propose a meta learning method for performing task-driven video summarization, denoted by MetaL-TDVS, to explicitly explore the video summarization mechanism among summarizing processes

Building occupancy estimation holds great promise for building control systems to save energy and provide a comfortable indoor environment. Existing solutions turn out to be lacking in practice due to their specific hardware requirements and/or poor performances. Recently, an light-emitting diode (LED) light sensor based occupancy estimation system, which is nonintrusive and does not require any additional

The application mapping problem is an NP-hard combinatorial optimization problem in network-on-chip (NoC) design. Applications of size ( $n$ $ >$ 30) cannot be solved optimally by an exact algorithm in reasonable time, and the evolutionary algorithms have drawn the attention of NoC researchers. In this paper, we propose a new effective optimization method based on the discrete particle swarm optimization

The valve-side single-phase-to-ground (SPG) faults in the half-bridge modular multilevel converter (HB-MMC)-based bipolar high-voltage direct-current (HVdc) systems induce some special fault consequences: overvoltage on the submodule (SM) capacitors in converter upper arms and nonzero-crossing currents in the grid-side ac circuit breaker (ACCB). In this letter, a protection strategy based on converter-embedded

Time delay of the finite control set model predictive current control caused by a large amount of calculations will degrade the control performance of the permanent magnet synchronous machine system. This letter first demonstrates the delay issue at length. Then, a new direct compensation method, by predicting the current variation within the delay time, is proposed. In comparison with the traditional

This letter proposes a simple and effective hold-up time extension method for server power systems, in which the fan is only turned off during the hold-up time with ac input loss. Due to the elimination of the fan power in the proposed method, the efficiency of the dc–dc converter increases during the hold-up time; thus, the energy stored in the link capacitor decreases less sharply, compared with

The papers in this special section focus on position sensorless AC motor drives. Rotor position and speed information is crucial for highperformance ac machine drives. Since the merits, such as cost reduction, system downsizing, and reliability enhancement can be achieved through position sensorless (also noted as self-sensing) control, many techniques for a wide range of rotor speed from standstill