Large Power Applications Research Articles

Analysis of Thermal Performance of Various Battery Packs and Materials Used in Electric Vehicles: A Review

Electric powered vehicle popularity gives us better option for reducing the hydrocarbon emissions for the clean environment and will help to minimizing the troposphere of ozone degradation. Evs that are powered by batteries are becoming more commonplace worldwide. A strong Battery Management System (BMS) is essential for the reliable and safe operation of batteries, which have been widely used in many large power applications, including EVs and hybrid EVs. Their optimal plan and the management are significant for safe and beneficial tasks. This review paper examined with about the oldest kind of battery-latest powered battery (Pb-acid battery) and the most recent innovation of battery, lithium-ion battery. The present paper deals about the recent improvement in three important areas like Battery pack shape, different battery material and thermal behaviour which covered main challenges for EVs operation.

Design, Fabrication and Performance Evaluation of Conductors in Tube Cables

With excellent mechanical properties and electromagnetic properties, compact superconducting cables are considered as potential candidates for large capacity power applications and fusion magnets. In this paper, the concept of a novel compact cable, conductors in tube (CIT) cable is introduced from the aspect of design, fabrication, and performance evaluation, respectively. The principal advantages of CIT cables are that the cable can release the residual stress created from the fabrication process, and the outer former of the cable can be used as both the supporter as well as the container of refrigerant liquid. Firstly, the topological structure and the detailed fabrication process of a CIT cable are presented. Then, a typical CIT cable is manufactured. The feasibility of this new structure is verified by its critical current test. Moreover, bending characteristics of CIT cables are evaluated and compared with Conductors on Round Core (CORC) cables from the aspect of both simulation and experiments. The superior bending performance enables it to be potential in the future compact magnet application.

Detection of Winding Asymmetries in Wound-Rotor Induction Motors via Transient Analysis of the External Magnetic Field

Over recent decades, the detection of faults in induction motors (IMs) has been mainly focused in cage motors due to their extensive use. However, in recent years, wound-rotor motors have received special attention because of their broad use as generators in wind turbine units, as well as in some large power applications in industrial plants. Some classical approaches perform the detection of certain faults based on the fast Fourier transform analysis of the steady state current (motor current signature analysis); they have been lately complemented with new transient time–frequency-based techniques to avoid false alarms. Nonetheless, there is still a need to improve the already existing methods to overcome some of their remaining drawbacks and increase the reliability of the diagnostic. In this regard, emergent technologies are being explored, such as the analysis of stray flux at the vicinity of the motor, which has been proven to be a promising option to diagnose the motor condition. Recently, this technique has been applied to detect broken rotor bar failures and misalignments in cage motors, offering the advantage of being a noninvasive tool with simple implementation and even avoiding some drawbacks of well-established tools. However, the application of these techniques to wound rotor IMs (WRIMs) has not been studied. This article explores the analysis of the external magnetic field under the starting to detect rotor winding asymmetry defects in WRIMs by using advanced signal processing techniques. Moreover, a new fault indicator based on this quantity is introduced, comparing different levels of fault and demonstrating the potential of this technique to quantify and monitor rotor winding asymmetries in WRIMs.

Four Level Flying Capacitor Multilevel Inverter with Phase Shifted Carrier-PWM Technique

Multilevel inverter is a type of inverter topology used for areas under large power applications. In this paper a four level Flying Capacitor MultiLevel Inverter with Phase Shifted-carrier PWM technique is discussed and simulated using Matlab/simulink. The positive and negative levels of the inverter at the output are equal . The inverter uses three carrier waves, and one trapezoidal wave as the reference signal for pulse generation. The comparison between the THD of pole voltage and line voltage of the inverter is also done in this paper.

Experimental Test and Analysis of AC Losses in Multifilamentary MgB2 Wire

AC losses in superconductors are essential for the design of cooling system for large scale power applications. Magnesium diboride (MgB2) superconducting wires have been investigated and manufactured over the last decade due to cheap raw materials and flexibility for coil design. In addition, multifilamentary MgB2 wires have been manufactured to reduce ac losses. In this paper, self-field ac losses of multifilamentary MgB2 wires with magnetic barrier are investigated using both experimental and numerical methods. A short straight wire sample and a coil sample are tested under various temperatures and frequencies between 16- and 128-Hz. The test results show that the transportation loss is independent of the operating temperature. On basis of both theoretical and numerical study, it is found that hysteresis loss in superconductor accounts only for a small fraction of the transportation losses, ferromagnetic hysteresis loss in the magnetic barrier dominates when the transport current is low, whereas eddy current loss dominates when the transport current is close to the critical current.

A Current Balance Control Strategy Applied in Inductively Coupled Power Transfer System With Multiple Parallel Pickup Modules

For large power application of inductively coupled power transfer (ICPT) system, such as traffic railway, multiple pickups have to be adopted. The condition exists that current unbalance of ICPT system with multiple parallel pickup modules, which will cause instability and low reliability. Aimed to solve the issue, the paper analyses the uncoupled module of ICPT system, assesses the impact of the mutual inductance, compensated state, and coil resistance on current unbalance, and put forward a novel current-balance strategy to balance the parallel currents by introducing the circuit of impedance transformation including semi-controlled rectifier, and BUCK, and BOOST circuits. Experiments have been done on the platform of ICPT prototype, and the experimental results are presented to show the correctness of the theoretical analysis and the effectiveness of the control strategy. When the output voltage is 220 V and load is 6 Ω, the output power is 8 kW. The amplitude ratio of the two parallel currents is 2.04 without control, and the amplitude of the two current is almost equal when adopting the strategy. System efficiency stays constant or increases slightly after adopting the proposed control strategy.

A 10 kW ZVS Integrated Boost Dual Three-Phase Bridge DC–DC Resonant Converter for a Linear Generator-Based Wave-Energy System: Design and Simulation

The design and performance analysis of a 10 kW three-phase DC–DC LCL-type resonant converter having a built-in boost function were carried out. This high-power converter is proposed for its application in grid-interfacing a linear generator (LG)-based wave-energy system. Fixed-frequency control is used, and the converter was designed to operate with a lagging power factor. It is shown that all switches turn on with zero-voltage switching (ZVS) for wide input voltage and load variations. This results in reduced switching losses and stresses, which is very important in large-power applications. The performance of the converter was studied through PSIM simulation software. Theoretical and simulation results are presented for comparison. Power-loss break-down analysis of the designed converter was carried out and the summary of results is presented.

A Three-Phase to Single-Phase AC-DC-AC Topology Based on Multi-Converter in AC Electric Railway Application

An AC-DC-AC topology based on multi-converter is proposed in this paper. It can match the capacity of the converter for high voltage and large power applications. This structure is not only suitable for solving the power quality problems of electrified railways, but also has its own superiorities. Its architecture and advantages in the traction application are analyzed in depth, and the design calculation of the main elements is presented. The control system of the proposed topology is designed, where dc current feedforward control is adopted to relieve the impact of the load mutation on the system. Its modular structure and simple current sharing control provide convenience for the capacity expansion. The software simulation and experiment based on a 45kVA prototype validate the proposed structure, and they are all compared with the traditional power supply systems. The simulation results indicate that this topology can not only satisfy the voltage and power requirements of traction load and solve the power quality problems, but also have its own superiorities in the application of electrified railways. The experimental results verify the correctness and validity of the scheme.

Analysis and experimental validation of longitudinally composite ultrasonic transducers.

The longitudinally cascaded piezoelectric ultrasonic transducer is studied which is composed of two longitudinally sandwiched piezoelectric transducers connected together mechanically in series and electrically in parallel. When the losses and load are taken into account, the electromechanical equivalent circuit of the transducer is obtained; the input electric impedance is analyzed and the resonance/anti-resonance frequency equations are obtained assuming one dimensional longitudinal vibrational theory. The relationship among the resonance/anti-resonance frequency, the effective electromechanical coupling coefficient, the mechanical quality factor and the electro-acoustic efficiency with the geometrical dimension, the losses, and the load is analyzed. Two longitudinally composite transducers are designed, made, and measured. It is shown that the theoretical resonance/anti-resonance frequencies, the effective electromechanical coupling coefficient, and the mechanical quality factor are in good agreement with the experimental results. It is expected that this kind of composite transducer can be used in large power and high intensity ultrasonic applications, such as ultrasonic liquid processing, ultrasonic metal machining, and ultrasonic welding and soldering.

Investigation of gear pitting defect using vibration characteristics in a single-stage gearbox

Gearboxes are the important components in process industries such as cement, food processing and rubber. Pitting is the removal of the material in certain part of gear by the application of repeated stresses. Tooth pitting and surface failure occur due to excessive stress conditions. When a number of pits join together, a larger pit is formed, referred as a spall, which may lead to tooth breakage. The early detection and diagnosis of excessive wear tooth pitting and spalling in gear transmission systems are becoming significant concerns in high-speed, large power applications. The early detection of pitting in gears is important from condition monitoring point of view, which is still to be addressed by an experimental approach. In this study, vibration characteristics of a single-stage spur gearbox with pitting as seeded faults are investigated.

Wireless Power and Bidirectional Data Transfer Scheme for Battery Charger

Wireless battery charging has been becoming a recent trend in mobile devices. However, there are relatively less research efforts focusing on the large power applications. It is a major drawback of the battery charging in traditional electric vehicles which relies on the use of a plug-in charging device. This paper proposes a wireless power and bidirectional data transmission scheme, data related to battery status, vehicle identification number, or emergency messages that can be mutually transmitted between two isolated units via the same LC tank. The primary unit employs an inverter to yield alternating current and power flow to the load via mutual inductance. The secondary unit transfers data by adjusting current of load, and the primary unit receives data based on the zero-voltage switching method. The primary unit transfers command by trimming the current's curve and the secondary unit receives command and make decoding using the period of carrier wave. It is worth to mention that the design scheme enables it to handle the situation of emergency by sending back the message to the primary unit to make an emergency halt.

A Fixed-Frequency ZVS Integrated Boost Dual Three-Phase Bridge DC–DC LCL-Type Series Resonant Converter

A new fixed-frequency controlled three-phase dc–dc LCL-type series resonant converter with integrated boost function is proposed for medium to large power applications with wide input voltage variation that is typical of alternate energy sources. The converter includes a dual three-phase LCL-type resonant bridge inverter modules connected in parallel, thus significantly reducing the component stresses when subjected to medium to large power applications. The fixed-frequency control of the output power is achieved by phase shifting the gating signals of one module with respect to the other, while the rectified voltage at the secondary windings of a three-phase high-frequency transformer connected between the two modules is added to the input voltage to boost the supply voltage to the modules. The zero-voltage-switching of all the switches is accomplished by designing the converter to operate in the lagging PF mode for wide variations in the input voltage and the load. Detailed modeling of the three-phase boost section is done and the steady-state analysis of the proposed converter for three-phase LCL-type dc–dc converter modules using complex ac circuit analysis method is presented. For illustration purpose, a dc–dc converter of 600 W is designed, and its performance is verified using PSIM simulations. An experimental model of the converter is built in the laboratory to verify its performance for wide variations in input voltage and load changes.

Real‐time implementation of three‐phase single‐stage SPV grid‐tied system using TL‐VSC

This work deals with real-time implementation of a three-phase single-stage solar photovoltaic (SPV) grid-tied system using a three-level voltage source converter (TL-VSC) working at lower switching frequency of 900 Hz under varying solar intensity levels for large power applications. The proposed system consists of SPV array, TL-VSC, interfacing inductors, and three-phase AC grid. The decoupled current controller with the capacitor voltage balancing control and an incremental conductance maximum power point tracking (IC-MPPT)-based algorithms are used to control the TL-VSC to track and transfer maximum active power to AC grid at unity power factor from SPV array. Owing to low switching frequency and single-stage topology, the efficacy of the system is increased. The performance of SPV grid integrated system using TL-VSC is validated under varying solar intensity levels in the laboratory at different switching frequencies and interfacing inductors in accordance to IEEE 519 standard.

Modeling and characteristic study of solar photovoltaic system under partial shading condition

The ever-increasing energy demand along with the rapid reduction of fossil fuels and to mitigate environmental issues, nowadays renewable energy becomes the main source of electrical energy across the globe. The recent upsurge in the demand of Photovoltaic(PV) systems is due to the fact that they produce electrical energy which requires less maintenance and is clean in nature .PV energy can be obtained directly by converting the solar energy into electrical energy. The main challenge in the PV system is that its characteristics depends upon environmental conditions and it is highly non-linear in nature. With change in temperature and irradiance conditions, the PV characteristic changes. For large power applications, photovoltaic arrays are required in the place of modules. To extract the maximum power from the PV array, maximum power point tracking algorithms (MPPT) with converters are essentially required. For large array, there is a possibility of shadow condition because of the nearby buildings, trees and the array itself causing partial shading of PV system. PV array experience partial shading under the condition where different modules of the array get different solar irradiance. This paper focuses on modelling and study of current-voltage and power-voltage characteristics of a PV array under the condition where different modules get different irradiance level. For ease the series-parallel and total-cross-tied configuration analysis is being done in the paper. The MATLAB simulation results show the occurrence of multiple peaks in current voltage and power voltage characteristic under partial shading condition.

Redox-Active Organic Molecule As High Performance Cathode Material for Non-Aqueous Rechargeable Magnesium-Ion Batteries

The rapid worldwide energy consumption is necessitating more energy generation from environmentally benign sources like solar, wind, or tide. However, the lack of efficient energy storage devices is the major limitation for the practical harvest of these clean energies. Rechargeable batteries are the promising solution for the efficient energy storage. We have witnessed the great success of secondary lithium-ion batteries (LIBs) in portable electronic devices in the last two decades. However, the cost and safety barriers make traditional LIBs not desirable to meet the requirements for large power applications, such as the electric or plug-in hybrid vehicles. In contrast, the multivalent ion rechargeable batteries such as Mg1-3 and Ca4 , 5 ion batteries are more promising as larger and safer energy storage devices due to their advantages in safety, cost and capacity. For instance, compared to lithium, magnesium metal is non-toxic, more air resistant and free from the dangerous dendrite formation. The higher natural abundance of magnesium makes it more than 20 times cheaper than lithium in cost. In addition, the divalent characteristic of magnesium ion (Mg2+) enables magnesium to have a nearly doubled volumetric capacity as an anode than the lithium (3832 mA cm-3 vs 2062 mA cm-3). All these merits have brought significant attention on magnesium-ion batteries as the new generation rechargeable energy storage device. Inspired by the pioneer work by Aurbach group for the development of the famous dichloro-complex magnesium electrolyte (2EtAlCl2-MgBu2),6 a lot of efforts have been devoted to the development of high voltage electrolytes for rechargeable magnesium-ion batteries. In contrast to the rapid development of effective magnesium electrolytes capable of reversibly plating/stripping magnesium with wide electrochemical windows, the design of high potential cathode material for magnesium ion batteries is far behind. To date, the Chevrel phase Mo6S8 is still the only cathode material with excellent cycling reversibility and reasonable rate capability in rechargeable magnesium-ion batteries. However, Mo6S8 could only operate at a relatively low voltage in magnesium-ion batteries (< 1.3 V) with a typical below 100 mAh g-1 capacity. Thus, development of high operating voltage cathode material deserves great attention in nowadays. Herein, we would like to present our recent progress on the development of high voltage and high performance rechargeable magnesium-ion batteries using redox active organic molecules as cathode material. As shown in Figure 1(a), when the 0.3M Mg(HMDS)2-4MgCl2 in THF solution was used as the electrolyte,7 excellent reversible redox processes have been observed in the cyclic voltammetry measurement when the redox active organic molecule was used as the cathode material. The redox potential was detected at around 1.7 V (vs Mg/Mg2+), which is much higher than the well-known Chevral phase Mo6S8. The compatibility and reversibility of the organic cathode material with the electrolyte and magnesium metal anode was further demonstrated in the batteries upon cycling. As shown in Figure 1(b), excellent cycling performance has been observed with around 120 mAh g-1 initial specific discharge capacity at the current rate of 0.5C, and still about 102 mAh g-1specific discharge capacity was obtained in 100 cycles (around 84% capacity retention). The results further suggest the great success of using redox active organic molecules as cathode material for secondary multivalent-ion batteries. (1) Muldoon, J.; Bucur, C. B.; Gregory, T. Chem Rev 2014, 114, 11683. (2) Saha, P.; Datta, M. K.; Velikokhatnyi, O. I.; Manivannan, A.; Alman, D.; Kumta, P. N. Prog Mater Sci 2014, 66, 1. (3) Yoo, H. D.; Shterenberg, I.; Gofer, Y.; Gershinsky, G.; Pour, N.; Aurbach, D. Energ Environ Sci 2013, 6, 2265. (4) Padigi, P.; Goncher, G.; Evans, D.; Solanki, R. J Power Sources 2015, 273, 460. (5) Lipson, A. L.; Pan, B.; Lapidus, S. H.; Liao, C.; Vaughey, J. T.; Ingram, B. J. Chem Mater 2015, ASAP. (6) Aurbach, D.; Lu, Z.; Schechter, A.; Gofer, Y.; Gizbar, H.; Turgeman, R.; Cohen, Y.; Moshkovich, M.; Levi, E. Nature 2000, 407, 724. (7) Liao, C.; Sa, N.; Key, B.; Burrell, A. K.; Cheng, L.; Curtiss, L. A.; Vaughey, J. T.; Woo, J. J.; Hu, L. B.; Pan, B. F.; Zhang, Z. C. Journal of Materials Chemistry A 2015, 3, 6082. Figure 1

Modeling the Non Linear Behavior of a Magnetic Fault Current Limiter

Fault Current Limiters are used in a wide array of applications from small circuit protection at low power levels to large scale high power applications which require superconductors and complex control circuitry. One advantage of passive fault current limiters (FCL) is the automatic behavior that is dependent on the intrinsic properties of the circuit elements rather than on a complex feedback control scheme making this approach attractive for low cost applications and also where reliability is critical. This paper describes the behavioral modeling of a passive Magnetic FCL and its potential application in practical circuits.

A Traction Three-Phase to Single-Phase Cascade Converter Substation in an Advanced Traction Power Supply System

The advanced traction power supply system (ATPSS) is a new directional development for traction power supply systems, which can totally remove the neutral sections and effectively promote power quality. However, the existing converters suffer from small substation capacity. In this paper, a new configuration based on a three-level neutral point clamped (3L-NPC) three-phase to single-phase cascade converter in a substation is proposed for ATPSS, which can be used to match the capacity of the converter for high voltage and large power applications. The control strategy of the proposed converter is analyzed in depth, and the phase disposition sinusoidal pulse width modulation (PD-SPWM) with phase shift carrier SPWM (PSC-SPWM) is employed in the inverters. Then, the inductance equalizing circuit is applied for the voltage balance on the DC-link. Besides, a LC filter circuit is designed to eliminate the double line-frequency ripple of DC voltage. Afterwards, a simulation model and an experimental prototype are developed, respectively. The simulation results show that the proposed converter in this paper can not only meet the requirements of voltage and capacity for the traction network, but also improve power quality. Finally, the experimental results verify the correctness and feasibility of the proposed control strategy.

Three-Phase AC Arc Plasma Systems: A Review

Most arc plasma systems are based on DC plasma technologies. However AC plasma systems can offer significant advantages versus DC plasma systems particularly in terms of efficiency, cost and reliability. They are also likely to overcome some of the limits of classical DC systems for some specific large scale high power applications. This paper presents a literature review of three-phase AC plasma systems which have been developed by the most active research groups on multi-phase AC plasma systems in the United States, Norway, Germany, Russia, France, and Japan for about 50 years.

Coreless, Contactless Power Supply System with DSP Controlled Active Compensation of Parameter Changes

Contactless power supply systems are of high interest in small power and large power applications. Many high efficiency contactless systems use the resonant operation mode. A parallel compensation system is presented enlarging overall system safety and allowing for resonant system parameter change while maintaining zero current switching (ZCS) operation. Basics of digital control unit construction and operation are presented. Simulation and experimental results are given for control system operation. Systems performance allows for large resonant circuit parameter drift. Modern DSP control unit minimizes the necessary external circuitry and time delays in case of most important operations. DOI: http://dx.doi.org/10.5755/j01.eee.20.10.4989

Characteristics of motorized spindle supported by active magnetic bearings

A motorized spindle supported by active magnetic bearings (AMBs) is generally used for ultra-high-speed machining. Iron loss of radial AMB is very great owing to high rotation speed, and it will cause severe thermal deformation. The problem is particularly serious on the occasion of large power application, such as all electric aero-engine. In this study, a prototype motorized spindle supported by five degree-of-freedom AMBs is developed. Homopolar and heteropolar AMBs are independently adopted as radial bearings. The influences of the two types of radial AMBs on the dynamic characteristics of the motorized spindle are comparatively investigated by theoretical analysis, test modal analysis and actual operation of the system. The iron loss of the two types of radial AMBs is analyzed by finite element software and verified through run-down experiments of the system. The results show that the structures of AMB have less influence on the dynamic characteristics of the motorized spindle. However, the homopolar structure can effectively reduce the iron loss of the radial AMB and it is useful for improving the overall performance of the motorized spindle.