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Short-term household electricity load forecasting is important for utility companies to ensure reliable power supplies. Traditional methods for load forecasting relied on historical records from one single data source and have limitations with insufficient or missing data. Recently, an emerging family of machine learning algorithms, multitask learning (MTL), has been developed and has the potential for load forecasting. By MTL, the electricity consumption data from multiple communities can be fused to improve forecasting accuracy. However, appropriate modeling of the relatedness to enable the between-community knowledge transfer remains a challenge. This paper proposes an improved MTL algorithm for a Bayesian spatiotemporal Gaussian process model (BSGP) to characterize the relatedness among the different residential communities. It hypothesizes on the similar impacts of environmental and traffic conditions on electricity consumption in improving short-term load forecasting. Furthermore, this paper proposes a low-ranked dirty model along with an iterative algorithm to improve the learning of model parameters under an MTL framework. This paper uses a real-world case study from two residential communities in Tallahassee, Fl, USA, to demonstrate the method effectiveness. The proposed method significantly outperforms state-of-the-art forecasting methods and effectively captures the relatedness to provide between-community knowledge transfer compared with other MTL methods. [ABSTRACT FROM AUTHOR]

This paper calculates and compares the efficiency and loss distribution in the three most popular state-of-the-art types of large motor drive systems: 1) current-source drive with active front-end rectifier; 2) current-source drive with 18-pulse thyristor rectifier; and 3) three-level voltage-source drive with 12-pulse/24-pulse diode rectifier. For converter systems with efficiencies better than 90%, it is suggested to calculate or measure the losses of all the components separately and add them up to calculate the total efficiency. A simple and accurate method of calculating switching losses for a current-source and voltage-source converter is proposed. Through the calculation and simulation of each loss factor such as switching losses, conduction losses, and snubber and filter losses, the three-level voltage-source drive system has been found to have the highest efficiency of 98.77% under the rated load of 1.6 MW. [ABSTRACT FROM AUTHOR]

The demand for electricity for the fused magnesia smelting process is calculated by the moving average of the energy consumption of a given period, which gives the efficiency of the smelting and indicates if the power supply should be cut off. Therefore, demand forecasting is very important for the operation of the smelting process. However, it is difficult to forecast demand since the power changes depend on the smelting process and raw materials. To obtain an accurate model, the mechanism model of the smelting process is combined with the data-driven method using artificial intelligence technology in this paper. The mechanism model is described by a linear model with unknown parameters. The uncertainties and error of the mechanism model are modeled by neural networks with unknown order. The maximal information coefficient method and the rule reasoning are combined to identify the order. To effectively combine the mechanism model and the data-driven model, a new saturated alternating identification strategy is proposed. The results of simulations and industrial applications show that the effectiveness of the proposed intelligent method of demand forecasting has been validated. [ABSTRACT FROM AUTHOR]

Competitive strategic bidding optimization is now a key issue in electricity generator markets. Digital ecosystems provide a powerful technological foundation and support for the implementation of the optimization. This paper presents a new strategic bidding optimization technique which applies bilevel programming and swarm intelligence. In this paper, we first propose a general multileader-one-follower nonlinear bilevel (MLNB) optimization concept and related definitions based on the generalized Nash equilibrium. By analyzing the strategic bidding behavior of generating companies, we create a specific MLNB decision model for day-ahead electricity markets. The MLNB decision model allows each generating company to choose its biddings to maximize its individual profit, and a market operator can find its minimized purchase electricity fare, which is determined by the output power of each unit and the uniform marginal prices. We then develop a particle-swarm-optimization-based algorithm to solve the problem defined in the MLNB decision model. The experiment results on a strategic bidding problem for a day-ahead electricity market have demonstrated the validity of the proposed decision model and algorithm. [ABSTRACT FROM AUTHOR]

Physical-layer-assisted power management (PA-PM) has great potential for reducing packet delay and lowering power consumption significantly. In PA-PM, the access point transmits the signature of a station to notify it of receiving packets, while the station performs low-power physical-layer correlation operations to detect its signature from the received signal. The detection performance of the signature has a crucial impact on the performance of PA-PM. In this paper, focusing on a polling scheme with PA-PM, we are the first to propose a novel queueing model to study the impact of the detection performance on the packet delay and the power consumption. Our model is applicable to homogeneous and heterogeneous traffic. Based on this model, we can optimize the sleeping interval of a station that minimizes the power consumption while meeting the delay requirement. Extensive simulations verify that our model is very accurate. This study can help system developers choose optimal system parameters (such as the sleeping interval and the signature length) and promote the practicality of PA-PM. [ABSTRACT FROM AUTHOR]

This paper describes the design of a precision bipolar junction transistor based temperature sensor implemented in standard 0.7-μm CMOS technology. It employs substrate p-n-ps as sensing elements, which makes it insensitive to the effects of mechanical (packaging) stress and facilitates the use of low-cost packaging technologies. The sensor outputs a duty-cycle-modulated signal, which can easily be interfaced to the digital world and, after low-pass filtering, to the analog world. In order to eliminate the errors caused by the component mismatch, chopping and dynamic element matching (DEM) techniques have been applied. The required component shuffling was done concurrently rather than sequentially, resulting in a fast DEM scheme that saves energy without degrading accuracy. After a single-temperature trim, the sensor's inaccuracy is ±0.1 °C (−20 to 60 °C) and ±0.3 °C (−45 to 130 °C), respectively. Measurements of sensors in different packages show that the package-induced shift is less than 0.1 °C. Measurements of eight sensors over 367 days show that their output drift is less than 6 mK. While dissipating only 200 μW, the sensor achieves a resolution of 3 mK (rms) in a 1.8-ms measurement time, and a state-of-the-art resolution figure of merit of 3.2 pJK2. This combination of high accuracy, high resolution, high speed, and low-energy consumption makes this sensor suited for commercial and industrial applications. [ABSTRACT FROM AUTHOR]

Smart devices are becoming a convergent platform for multimedia sensing, computing, and communication. Digital oil painting (DOP) is a revolutionary technique where a digital artist uses a digital paintbrush to simulate the traditional bristle paintbrush of a painting to get an oil paint image. Artists explore the perceiving moods of people through colors and lights in the painting. In this paper, we attempt to exploit the convergence toward the problem of automatically transferring mood of a user in DOP in terms of ambient light and color perception. We propose a mood-based oil painting technique that can be implemented and used in current smart devices in real time without using any explicit hardware. The proposed technique is optimized significantly by reducing the processing time and power consumption. We also develop a prototype on Android operating system to create mood-based oil paint images. [ABSTRACT FROM AUTHOR]

Dynamic wireless charging of electric vehicles (EVs) aims at increasing EV range and reducing battery size and associated costs. Moreover, it minimizes the need for recharging stops, thus increasing travel comfort. As electrification of transport ultimately targets CO2 emissions reduction, increased utilization of renewable energy sources is likely to provide the means for reaching the decarbonization objectives. Demand-side management (DSM) enables the increased penetration of intermittent power sources by providing techniques that ensure grid stability. While complete frameworks for DSM deployment in static charging have been designed, these approaches must be re-evaluated with focus on the operational requirements for dynamic EV charging. In this paper, a review of DSM methods targeting static charging is made and one particular case of DSM is simulated in a dynamic charging environment in order to reveal critical aspects towards deployment. [ABSTRACT FROM PUBLISHER]

In this paper, a direct ac–dc power electronic converter topology is proposed for efficient and optimum energy harvesting from low-voltage microgenerators. The converter utilizes the bidirectional current-conduction capability of MOSFETs to avoid the use of a front-end bridge rectifier. It is operated in discontinuous conduction mode and offers a resistive load to the microgenerator. Detailed analysis and modeling of the converter is presented. In such low-power applications, the power consumption of gate drive and control circuits should be minimal. In this paper, they are specifically designed to consume very low power. A suitable startup circuit and auxiliary dc supply circuit is proposed for the implementation of the converter. A low-voltage microgenerator is used to verify the performance and operation of the converter and the gate drive circuits. [ABSTRACT FROM AUTHOR]

Address driver circuits are responsible for a significant portion of power consumption by a plasma display panel television. In the latest effort for the reduction of the power consumption by address driver circuits, the power-efficient operation mode is selected by controlling the voltage of the capacitor that affects the LG resonance. This paper presents an analysis of power consumption by the address circuits and observes that the operation mode change in a previous work is too slow to achieve an efficient power reduction when the number of data switchings of each scan line changes abruptly in the input image. This paper proposes a new power reduction method with a fast selection of the operation mode based on the analysis of the power consumption by each address operation mode. The fast mode selection enables rapid change of the address operation mode and consequently leads to a reduction of power consumption by 22.2% when compared with the previous method. [ABSTRACT FROM AUTHOR]

The main purpose of this paper is to develop reliable and affordable tools and methodologies for the design, simulation, and fault analysis of Controller Area Network (CAN) bus networks. In this paper, a behavioral model of a CAN bus transceiver is proposed and experimentally verified. Moreover, we developed a methodology to efficiently manage the trade-off concerning accuracy, simulation speed, and convergence issues which are usually involved in the simulation of large CAN bus networks. To this aim, three different architectures of the transceiver behavioral model have been implemented: They can be selected by the user to address specific requirements of intended analyses. The architectures are based on a set of behavioral models of the basic mixed-signal circuit building blocks of the transceiver. The models were implemented using the VHDL-AMS language. Signal integrity, fault analysis, power consumption analysis, corner analysis, etc., can be effectively and reliably implemented. Simulation and experimental results, which demonstrate our approach efficiency, are reported. [ABSTRACT FROM AUTHOR]

This paper proposes new practical optimal current control methods for a newly emerging class of synchronous motors with hybrid rotor fields by both permanent magnet and winding. In a practical situation with limited voltage, the extensively used permanent-magnet synchronous motor hardly achieves an ideal performance in an energy-efficient manner due to its constant magnet field, which simultaneously allows both low-speed high-torque and wide speed-range operations. The hybrid-field synchronous motors (HFSMs) are potential candidates that can achieve the ideal performance as practical motors with control- lable hybrid rotor field. HFSMs can dynamically control the rotor flux according to the operation requirements by the low-speed, high-torque, and wide speed-range operations, etc. For the HFSMs, the same torque can be produced by a variety of stator and rotor currents due to the nonlinearity between the torque and the currents. Produced losses and required voltages depend upon the associated currents. Consequently, in the situation that current control systems are well constructed, appropriate determination of a set of stator and rotor current commands plays a key role to achieve the ideal performance in an energy-efficient manner. The proposed methods determine the current commands corresponding to a given torque command such that the total winding copper losses due to the stator and rotor currents can be minimized if the exact currents associated with the torque command exist; the best approximate torque can be produced if no exact associated currents exist, which is, of course, under the circumstance of a voltage limitation. The determined current commands are optimal in the sense of energy efficiency or degree of approximation under voltage limitation. New recursive algorithms searching the optimal current solution in real-time are also given as parts of the methods. The proposed methods are analytical but practical, whose usefulness is verified through experiments. [ABSTRACT FROM AUTHOR]

There has been a considerable trend in the use of inverter supplies for induction motors over sinusoidal supplies due to the requirement of efficient control of these machines in many automated systems. However, the use of inverters introduces additional losses in the motor as a result of voltage and current harmonics which impact negatively on the motor efficiency. This paper provides some considerations for nonintrusive efficiency estimation of inverter-fed induction motors, focusing on the quantification of additional losses for different harmonic equivalent circuits and the effect of voltage and current harmonics on the performance of these motors. Based on the analysis of the existing efficiency estimation methods, recommended techniques are proposed for state-of-the-art methods. An application of such techniques is presented. The future trend of the efficiency estimation of inverter-fed induction motors is highlighted. The rotor speed estimation techniques are reviewed. [ABSTRACT FROM PUBLISHER]

In this paper, the electricity cost minimization problem is considered for a residential microgrid which consists of multiple households (users) equipped with renewable-based distributed energy resource (DER). Each user has a set of nonshiftable and shiftable loads. Bidirectional electricity transactions are allowed, and a dynamic pricing model for the purchasing/selling of electricity from/to the grid is proposed. In order to reduce the electricity cost, the following decisions needed to be made: 1) scheduling decisions for the shiftable loads; 2) purchasing/selling decisions for each user at each time slot; and 3) amount decisions of the electricity purchased/sold by the users. An optimization problem to minimize the total electricity cost is formulated to obtain the optimal amount of electricity consumed, sold, and purchased for each user, respectively. A centralized algorithm based on dynamic programming, $Q$-learning, and Lyapunov methods are proposed to solve the optimization problem with perfect information, with partial information, and without information of any time-varying parameters, respectively. For the latter two cases, distributed algorithms are designed for practical implementation. Simulation results show that the proposed schemes can provide effective management for household electricity usage and bidirectional transactions. [ABSTRACT FROM PUBLISHER]

In order to realize green ecosocieties, the total electric power consumption of computers and networks is required to be reduced. In applications on distributed systems, clients issue service requests to servers and then servers send replies to clients. Here, we discuss how much electric power a server consumes since the power consumption of a client is neglectable compared with a server. We classify applications into transaction- and communication-based ones. A server mainly consumes CPU resources to perform the transaction-based applications. On the other hand, a server consumes communication resources to transmit a large volume of data to a client in communication-based applications. In our previous studies, the power consumption laxity-based and extended power consumption-based algorithms are proposed to select one of servers so that the total power consumption of servers is reduced for transaction- and communication-based applications, respectively. However, most applications are mixed types, i.e., composed of both the transaction and communication processing modules. Hence, we consider the mixed types of applications in this paper. First, we integrate the power consumption models of transaction- and communication-based applications into a modified simple power consumption (MSPC) model of a server. Based on the MSPC model, we propose an algorithm to select one of servers for mixed types of applications so that the total power consumption of servers can be reduced. We show the power consumption of servers can be reduced in the algorithm through the simulation. [ABSTRACT FROM PUBLISHER]

The concept of microgrid is invented to harmonize local electricity production and consumption. The increasing interest on microgrids is caused by the considerable growth of renewable energy sources (RES) and distributed generation (DG). In a large geographical region, there can exist multiple microgrids. Many academic articles have reported the technicalities of microgrids operating in islanded mode, and few have analyzed their aggregated technical/economic impacts or benefits on the network in a larger region. Deregulation encourages RES to participate in energy markets to facilitate competition among different energy providers. Apart from participating in energy markets, an alternative way of making use of and making profit out of multiple microgrids is to take part in the ancillary-service market. This paper investigates the technical aspects of providing frequency control reserves (FCRs) and the potential economic profitability of participating in FCR markets based on a setup of multiple microgrids. In particular, it has a focus on the communication aspects under different market scenarios, i.e., decentralized or centralized coordination approach, for FCRs with the assumption of the possible aggregation of reserve provision from multiple microgrids (microsources and flexible loads). [ABSTRACT FROM AUTHOR]

The capacity to store energy in ultracapacitors or double-layer capacitors is about two orders of magnitude greater than that of ordinary capacitors. Also, their capability to receive and transfer power is greater than that of batteries in the same order of magnitude. These characteristics, together with their long life cycle ( > 500 000) and their lack of maintenance work, make them a suitable choice in replacing batteries in pulsed or discontinued power consumption systems. This paper tries to evaluate the possibility to replace batteries with ultracapacitors in Global System for Mobile Communications (GSM)-based remote supervision systems using photovoltaic panels as main power source. [ABSTRACT FROM PUBLISHER]

Reliability and precision are key requirements for electronic systems in aerospace applications. Transferring electrical energy from a stationary to a moving device involves wearable parts such as slip rings and brushes. This paper examines the possibility of using a rotating transformer for contactless transfer of energy from the base to the revolving platform of an airborne radar system. The first part of the series focuses on the magnetic interface, investigating its electrical properties and their association with the core and windings geometry. The reader will gain an understanding of the merits and limitations of this technology and will be able to assess its suitability for other applications. The effects of the increased leakage and reduced magnetizing inductances of the transformer are investigated, and two winding layouts are proposed and characterized by measurements and finite-element analysis. Some equations are presented along with practical guidelines on designing a rotating transformer with a 0.25-2-mm air gap. The transformer voltage gain and efficiency plots are introduced as performance-assessment tools. The impact of the air-gap stray flux on the winding conduction losses is shown, and some electromagnetic-compatibility considerations are presented. Finally, a mechanical layout for a 1-kW rotating transformer is proposed. [ABSTRACT FROM AUTHOR]

In contrast to hybrid electric cars (HECs), the issues concerning cost, volume, and reliability are even more rigorous when developing hybrid electric scooters (HESs). Therefore, the drive topology and control strategy used in HEC cannot be applied to HES directly. This paper presents a single-stage bidirectional dclac converter based on a general full-bridge inverter. The converter is designed for a low-voltage brushless dc motor/alternator (BLDCM/A) used in HESs, in which the additional bulky inductor and power switches are eliminated in the proposed design. In order to increase the reliability of the commutation process, a cost-effective sensorless control scheme for the motor and alternator commutation is developed. The commutation signals are extracted directly from the average terminal voltages, in which the motor neutral voltage, multistage analog filters, analog-to-digital converters, and the complex digital phase-shift (delay) circuits are eliminated. In addition, instead of using the complex flux-weakening control technique, the winding-changeover technique is exploited to extend the range of the operating speed. With attractive features, such as low cost and ease of implementation, the proposed approach is particularly suitable for electric bikes, electric scooters, HESs, etc. Theoretical analysis and several experiments are conducted to justify the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

A multisectional power driver design for the two-phase linear brushless motor will be proposed in this paper. The field-oriented modeling of the axial-flux linear brushless motor (AFLBM) will also be developed by using stationary and cosecant similarity transformation and singular value decomposition. Stationary and cosecant coordinate models will be derived based on the proposed approach. Decoupled relation and constant torque property will be obtained from the proposed models. Switching logic table for the linear motor operation is provided to drive the AFLBM properly. The switching-mode analysis for the power driver is also analyzed in detail. In order to increase the efficiency and the effectiveness of the electric motor applications, a multisectional driver circuit, which features the power driver with the so-called N + 2 structure, will be investigated and compared. Experimental results show that the proposed circuit design can achieve better performance with the higher efficiency. It is believed that the proposed driver circuit technique and system modeling can be very helpful to the control of railway transportations. [ABSTRACT FROM AUTHOR]

This paper presents a self-oscillating flyback converter with efficiency enhancement mechanisms using lossless snubber and the energy recovery winding. The conventional self-oscillating flyback converter with resistor–capacitor–diode snubber has the issues of low conversion efficiency and high no-load power loss. Furthermore, in order to fulfill the 95\ \mboxV\mathrm{p-p} voltage limitation of the IEC62684 Common-Mode (CM) Standard, the parasitic capacitor of a transformer between the primary and secondary windings has to be reduced, which leads to large leakage inductance for the transformer. However, the larger leakage inductance stores more energy to cause the high voltage spike on the main switch during the turnoff transition period. Therefore, the lossless snubber is employed to suppress the voltage spike and increase the conversion efficiency. In order to increase more conversion efficiency, the energy recovery winding is employed to recycle the energy discharged from the gate–source capacitor of the main switch. Furthermore, the burst-mode control mechanism is utilized to reduce the power consumption at the no-load and light-load conditions. Finally, a prototype circuit of the 7.5-W self-oscillating flyback converter with efficiency enhancement mechanisms is built to verify the performance feasibility, such as the CM voltage, the voltage stress on the switch, the conversion efficiency, and the no-load power loss. [ABSTRACT FROM PUBLISHER]

A new control technique for two-stage server power is proposed in this paper. The proposed technique will significantly reduce power consumption under the light-load condition. The basic idea of the proposed control technique is to control both the dc-link voltage of the power factor corrector (PFC) stage and the switching method of the full-bridge stage. Under the light-load condition, the output voltage of the PFC stage is no more fixed and is dynamically adjusted to significantly reduce the switching losses. Moreover, under the light-load condition, the full-bridge stage is with pulsewidth-modulation (PWM) and burst-mode control to reduce the circulating current losses. The former approach will reduce the switching losses due to the reduction of voltage across the power devices. The latter approach will dramatically reduce the circulating current losses caused by the phase-shift control method since phase-shift switching control is replaced by PWM switching control. Moreover, due to the reduction of the dc-link voltage, the switching losses for PWM and burst-mode control can be further reduced, as compared to those for fixed dc-link voltage. Experimental results of 480-W server power are presented. It is shown that the efficiency of the two-stage power converter can be improved up to 8% and 3.9% under light-load and 10% load conditions for \mboxinput voltage=110\ \mboxV, respectively. For the 220-V input voltage, the efficiency improvement using the proposed method is 6.4% and 4.2% under light-load and 10% load conditions, respectively. [ABSTRACT FROM PUBLISHER]

Researchers have shown that the Electronic Product Code (EPC) Class-1 Generation-2 (C1G2) specification has serious security problems. To overcome these weaknesses, some authors have proposed a specially designed pad generation (PadGen) function to improve security. The PadGen function is used to produce a cover-coding pad to mask the tag's access password before the data are transmitted. In this paper, we study the radio-frequency identification (RFID) tag–reader mutual authentication (TRMA) scheme. Two improved authentication protocols for generating the PadGen function are described. A hardware design of these RFID authentication protocols conforming to the International Standards Organization 18000-6 Type-C protocol, also known as EPC C1G2 RFID protocol, is proposed. Since tags have an extremely limited computing power and storage capacity, the PadGen function based on exclusive-or operation for low-cost hardware implementation is reported in this study. The proposed RFID TRMA protocol was simulated using Modelsim XE II and synthesized using Altera's Quartus II software. The functionality of these strengthening protocols was successfully verified in hardware using an Altera DE2 board that included an Altera Cyclone II field-programmable gate array. [ABSTRACT FROM PUBLISHER]

The recent worldwide measures for energy savings call for a larger awareness of the household energy consumption, given the relevant contribution of domestic load to the national energy balance. On the other hand, electricity smart meters together with gas, heat, and water meters can be interconnected in a large network offering a potential value to implement energy savings and other energy-related services, as long as an efficient interface with the final user is implemented. Unfortunately, so far, the interface of such devices is mostly designed and addressed at the utilities supervising the system, giving them relevant advantages, while the communication with the household is often underestimated. This paper addresses this topic by proposing the definition of a local interface for smart meters, by looking at the actual European Union and international regulations, at the technological solutions available on the market, and at those implemented in different countries, and, finally, by proposing specific architectures for a proper consumer-oriented implementation of a smart meter network. [ABSTRACT FROM AUTHOR]

Smart Grid technology is recognized as a key component of the solution to challenges such as the increasing electric demand, an aging utility infrastructure and workforce, and the environmental impact of greenhouse gases produced during electric generation. This paper presents the application of a hybrid optimization algorithm for distributed energy resource (DER) management in Smart Grid operation. The approach emphasizes the advantages of using multiagent systems for profitable operation of a Smart Grid in the energy market. The trading strategy adopted for the auction process is a profit-maximizing adaptive bidding strategy based on risk and competitive equilibrium price prediction. The auctioneer manages the usage of DERs by receiving bids from buyers and asks from sellers. A hybrid-immune-system-based particle swarm optimization is used to minimize the fuel cost for generation assuming realistic market prices for power, distributed generator bids reflecting realistic operational costs, and load bids customized according to the consumers' priorities. The simulation results clearly indicate that the agent-based management is effective in coordinating the various DERs economically and profitably. [ABSTRACT FROM AUTHOR]

This paper presents a zero-voltage (pulsewidth modulation) half-bridge inverter with active voltage clamping using only a single auxiliary switch. The structure is particularly simple and robust. It is very attractive for single-phase high-power applications. Switching losses are reduced due to implementation of the simple active snubber circuit that provides zero-voltage-switching conditions for all switches, which includes the auxiliary one. Its main features are simple modulation strategy, robustness, low weight and volume, low harmonic distortion of the output current, and high efficiency. The principle of operation for steady-state conditions, mathematical analysis, and experimental results from a laboratory prototype are presented. [ABSTRACT FROM AUTHOR]

Micro-power-consumption technique requires high-power-density dc/dc converters and power supply source. Voltage lift technique is a popular method to apply in electronic circuit design. Since a switched capacitor can be integrated into a power IC chip, its size is small. Combining switched-capacitor and voltage lift technique can construct dc/dc converters with small size, high power density, high-voltage transfer gain, high power efficiency, and low electromagnetic interference. This paper introduces a new series of dc/dc converters-positive output multiple-lift push-pull switched-capacitor dc/dc Luo-converters. [ABSTRACT FROM AUTHOR]

A magnetic link is established between the stationary and revolving frames of a radar system by means of a rotating transformer. Based on the magnetics analysis of Part I of the series, a design methodology is proposed for integrating a rotating transformer into a power electronic converter using the efficiency and voltage gain plots. It is shown that a phase-shifted full-bridge topology can effectively utilize the parasitic components of the transformer. The increased magnetizing current assists the resonant transition, and this, in turn, compensates for the increased conduction losses that a rotating transformer yields. The proposed design method secures the soft-switching operation of the converter over the entire load range and allows efficient operation and reduced electromagnetic emissions. The methodology is evaluated experimentally, and the resulting prototype demonstrates an average efficiency of 92.6% in the 0.2-1-kW output power range. The proposed topology extends the power capacity of the rotating transformer without compromising its size, cost, or performance. A comparison between the slip rings and rotating transformer solutions highlights the merits and weaknesses of each technology. [ABSTRACT FROM AUTHOR]

Describes a simple and effective control strategy for consumption power feedback of a power electronic burn-in test. System configuration of consumption power feedback unit(CPFU); Theoretical analysis of the proposed CPFU operates in the power control mode; Control system design of burn-in test systems; Experimental results of single-phase uninterruptible power system; Conclusions.

To improve the positioning accuracy of galvanometer scanners, we have developed a thermal demagnetization compensation (TDC) approach. In recent years, increase in power consumption of the galvanometer scanner results from high-speed motion; therefore, a magnet's temperature rise increases. Generated torque of the galvanometer scanner decreases with a rise in temperature because of demagnetization so that positioning ability of the galvanometer scanner declines. The proposed TDC approach estimates magnet temperature with a high degree of accuracy from the detected current using preidentified thermal characteristics. On the basis of estimated temperature, the TDC approach is able to compensate for generated torque fluctuation caused by the magnet's temperature rise without additional thermal sensors. Furthermore, the TDC performs efficiently even so the settling waveform has transient response error caused by continuous movement. In addition, the TDC approach performs for various operating frequencies. When we applied the TDC approach to galvanometer scanners installed on laser-drilling machine, the TDC approach reduced the maximum positioning error by 32$\%$, and all shots were less than an accuracy tolerance. [ABSTRACT FROM PUBLISHER]

The article informs that recent advancements in design, control and diagnostics in electromechanical-energy converters have motivated this special section on electric machinery and adjustable-speed motor drives-part I of the periodical "IEEE Transactions on Industrial Electronics." It is stated that efficiency in generation and consumption of electricity is a factor by which the future energy challenges will be affected. Due to this factor, as also stated, significance of research and development pertaining to conversion of electromechanical-energy continues to attract substantial attention from academia, industry and governments around the world.