Alternator

14,000,000 Leading Edge Experts on the ideXlab platform

Scan Science and Technology

Contact Leading Edge Experts & Companies

Scan Science and Technology

Contact Leading Edge Experts & Companies

The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform

David J. Perreault - One of the best experts on this subject based on the ideXlab platform.

  • Design and Evaluation of a 42-V Automotive Alternator With Integrated Switched-Mode Rectifier
    IEEE Transactions on Energy Conversion, 2010
    Co-Authors: Sai Chun Tang, Thomas A. Keim, David M. Otten, David J. Perreault
    Abstract:

    This paper presents techniques for the design of high-power Lundell Alternators with integrated switched-mode rectifiers. A multisection stator winding and interleaved rectifier arrangement is introduced that enables high power levels to be achieved using small semiconductor devices, and which greatly reduces the output filter capacitor requirements. We also demonstrate control methods suited for this interleaved system. In addition to accurate closed-loop output voltage control, we introduce methods to provide (partial) synchronous rectification for reduced loss, and to provide tight load-dump transient control. The proposed technology is validated in the design and experimental evaluation of a 42-V, 3.4-kW Alternator with fully integrated power electronics and controls. The prototype Alternator achieves approximately a factor of 2.1 increase in power and 1.6 increase in power density as compared to a conventional diode-rectified Alternator.

  • Thermal modeling of Lundell Alternators
    IEEE Transactions on Energy Conversion, 2005
    Co-Authors: Sai Chun Tang, Thomas A. Keim, David J. Perreault
    Abstract:

    Thermal analysis of Lundell Alternators used in automobiles is presented. An analytical thermal model for Lundell Alternators is proposed, and procedures for acquiring the model parameters are elucidated. Based on the thermal model, the temperature profile of an operating Lundell Alternator can be predicted analytically. The predicted Alternator temperatures are found to be consistent with the experimental measurement. The presented models and measurement methods are useful for embedding switched-mode power electronics into the Alternator with low manufacturing cost.

  • automotive power generation and control
    IEEE Transactions on Power Electronics, 2004
    Co-Authors: David J. Perreault, V. Caliskan
    Abstract:

    This paper describes some new developments in the application of power electronics to automotive power generation and control. A new load-matching technique is introduced that uses a simple switched-mode rectifier to achieve dramatic increases in peak and average power output from a conventional Lundell Alternator, along with substantial improvements in efficiency. Experimental results demonstrate these capability improvements. Additional performance and functionality improvements of particular value for high-voltage (e.g., 42 V) Alternators are also demonstrated. Tight load-dump transient suppression can be achieved using this new architecture. It is also shown that the Alternator system can be used to implement jump charging (the charging of the high-voltage system battery from a low-voltage source). Dual-output extensions of the technique (e.g., 42/14 V) are also introduced. The new technology preserves the simplicity and low cost of conventional Alternator designs, and can be implemented within the existing manufacturing infrastructure.

  • A New Design for Automotive Alternators
    2000
    Co-Authors: David J. Perreault, V. Caliskan
    Abstract:

    This paper introduces a new design for Alternator systems that provides dramatic increases in peak and average power output from a conventional Lundell Alternator, along with substantial improvements in efficiency. Experimental results demonstrate these capability improvements. Additional performance and functionality improvements of particular value for highvoltage (e.g., 42 V) Alternators are also demonstrated. Tight load-dump transient suppression can be achieved using this new design and the Alternator system can be used to implement jump charging (the charging of the high-voltage system battery from a low-voltage source). Dual-output extensions of the technique (e.g., 42/14 V) are also introduced. The new technology preserves the simplicity and low cost of conventional Alternator designs, and can be implemented within the existing manufacturing infrastructure.

Caiyong Ye - One of the best experts on this subject based on the ideXlab platform.

  • Study of a Novel High-Speed Compensated Pulsed Alternator With Multistage Stator Cores
    IEEE Transactions on Plasma Science, 2019
    Co-Authors: Jiangtao Yang, Caiyong Ye, Xin Liang, Fei Xiong
    Abstract:

    The compensated pulsed Alternators (CPAs) have good applications in high-energy lasers, electromagnetic rail guns, and other electromagnetic launch devices. Among various electrical machine topologies, homopolar inductor Alternators (HIAs) have attracted interest as CPAs due to their merits of simple and reliable structure, brushless excitation, and high-speed operation. However, the length of the conventional HIA is difficult to expand because it is limited by the rotor diameter, and the rotor diameter is restricted by the maximum speed of rotor tip, which results in low-energy storage capacity of a single machine. Besides, HIA suffers from the relatively low-power density due to its unipolar air-gap flux density (UAFD). To solve these problems, two novel HIAs with multistage stator cores (HIA-MSCs) are proposed in this paper. One is HIA with UAFD (HIA-UAFD) and the other is HIA with unipolar and bipolar air-gap flux density (HIA-UBAFD). First, the structure and operation principle of HIA-MSCs are illustrated. Then, the key parameters of HIA-MSCs are derived, and the corresponding models are built. Finally, the electromagnetic performances of HIA-MSCs are investigated by 3-D finite-element analysis method. Compared with HIA-UAFD, HIA-UBAFD has relatively higher discharge current and output power, which indicates that HIA-UBAFD is a better candidate for the pulsed Alternator.

  • Design and Research of a High-Speed and High-Frequency Pulsed Alternator
    IEEE Transactions on Plasma Science, 2017
    Co-Authors: Caiyong Ye, Jiangtao Yang, Xin Liang, Wei Xu
    Abstract:

    Pulsed Alternators have the merits of high energy and power densities, which are applied to a wide range of applications, such as the electromagnetic launch, the pulsed laser, and the pulsed high magnetic field. A new type of high-speed and high-frequency pulsed Alternator integrating an Alternator and a motor, is proposed in this paper. A solid rotor which is made of high-strength alloy steel with high yield strength is used in the pulsed Alternator, so it can work at a high tip speed. This machine consists of two Alternators and a motor which share one rotor and one field winding. According to different voltage levels and operation frequencies, the motor and the Alternators with different stack lengths and pole-pairs are designed, respectively. Therefore, it has the abilities of being driven by low-frequency current and discharging high-frequency pulses. In this paper, the basic structure and fundamental of the pulsed Alternator are introduced, the specific parameters of the prototype are given, and the performances are verified by the simulation. The results show that the machine proposed in this paper is suitable for the applications that require high-frequency pulsed discharge.

  • Optimized Design and Simulation of an Air-Core Pulsed Alternator
    IEEE Transactions on Plasma Science, 2015
    Co-Authors: Caiyong Ye, Kexun Yu, Hua Zhang, Lei Tang
    Abstract:

    The air-core pulsed Alternator has been studied for more than three decades. However, its optimized design theories are still rarely reported. The performance of the air-core pulsed Alternator-based pulsed-power system is often closely associated with the electrical machine parameters, the system structure, and the load requirements. The parametric optimization of this type of Alternator has a very important influence on the performance. This paper focuses on the optimization theory of the air-core pulsed Alternator design, including the optimization of the magnetic field distribution, the turn number of armature winding, and the turn number of field winding. The features of the magnetic field distribution in the air-core pulsed Alternators are analyzed based on the analytical expressions. By designing a ferromagnetic shield put on the outside of the stator, the radial magnetic field component increases and the circumferential one decreases. The optimization principles of the winding turn numbers are also deduced based on the system circuit and operation mode. The optimization theories are verified by system-level dynamic simulation. Finally, some rules are summarized, which are beneficial to the optimized design of the air-core pulsed Alternator.

  • Comparison Between Self-Excitation and Pulse-Excitation in Air-Core Pulsed Alternator Systems
    IEEE Transactions on Plasma Science, 2013
    Co-Authors: Caiyong Ye, Kexun Yu, Hua Zhang, Pei Yuan
    Abstract:

    Air-core pulsed Alternators greatly enhance the power density capabilities of pulsed power supply for electromagnetic launchers. Compared with iron-core electric machines, they require very high-excitation currents. Usually, the self-excitation mode is adopted in these systems. However, the self-excitation mode is a positive feedback process that should be precisely controlled to avoid the system being destroyed. The excitation losses are very large during the process of establishing the large field current. To solve these problems, a new excitation mode, the pulse-excitation mode, is presented in this paper. The main idea is that a pulsed current charges the field coil so that the field coil and the armature coil conduct only for a short time around the main discharge pulse. This will avoid the machine being overheated and the risk of positive feedback process. Compared with the self-excitation mode, the pulsed Alternator can be operated in a higher discharge frequency and the circuit schematic of the system is simpler. A larger field capacitor is used that charges the field coil to the desired current just by a pulse. As the energy density of pulse capacitor is enhanced rapidly, the volume and mass of the field capacitor are acceptable. The pulse-excitation mode is a combination of pulsed Alternator and pulsed capacitor. In this paper, the characteristics of self-excitation and pulse-excitation are analyzed, respectively. The performances of both systems are simulated, and the main waveforms are presented. Finally, there is a practical comparison between them.

  • Comparison between self-excitation and pulse-excitation in air-core pulsed Alternator system
    2012 16th International Symposium on Electromagnetic Launch Technology, 2012
    Co-Authors: Caiyong Ye, Kexun Yu, Pei Yuan
    Abstract:

    Air-core pulsed Alternators greatly enhance the power density capabilities of pulsed power supply for electromagnetic launchers. Compared with iron-core electric machines, they require very high excitation currents. Usually, the self-excitation mode is adopted in these systems. However, the self-excitation mode is a positive feedback process which should be precisely controlled to avoid the system being destroyed. The excitation losses are very large during the process of establishing the large field current. To solve these problems, a new excitation mode, pulse-excitation mode, is presented in this paper. The main idea is that a pulsed current charges the field coil so that the field coil and the armature coil conduct only for a short time around the main discharge pulse. This will avoid the machine being overheated and the risk of positive feedback process. Compared with self-excitation mode, the pulsed Alternator can be operated in a higher discharge frequency and the circuit schematic of the system is simpler. A larger field capacitor is used which charges the field coil to the desired current just by a pulse. As the energy density of pulse capacitor is enhanced rapidly, the volume and mass of the field capacitor are acceptable. Generally speaking, the pulse-excitation mode is a combination of pulsed Alternator and pulsed capacitor. In this paper, the characteristics of self-excitation and pulseexcitation are analyzed respectively. The performances of both systems are simulated, and the main waveforms are presented. Finally, there is a practical comparison between them.

V. Caliskan - One of the best experts on this subject based on the ideXlab platform.

  • automotive power generation and control
    IEEE Transactions on Power Electronics, 2004
    Co-Authors: David J. Perreault, V. Caliskan
    Abstract:

    This paper describes some new developments in the application of power electronics to automotive power generation and control. A new load-matching technique is introduced that uses a simple switched-mode rectifier to achieve dramatic increases in peak and average power output from a conventional Lundell Alternator, along with substantial improvements in efficiency. Experimental results demonstrate these capability improvements. Additional performance and functionality improvements of particular value for high-voltage (e.g., 42 V) Alternators are also demonstrated. Tight load-dump transient suppression can be achieved using this new architecture. It is also shown that the Alternator system can be used to implement jump charging (the charging of the high-voltage system battery from a low-voltage source). Dual-output extensions of the technique (e.g., 42/14 V) are also introduced. The new technology preserves the simplicity and low cost of conventional Alternator designs, and can be implemented within the existing manufacturing infrastructure.

  • A New Design for Automotive Alternators
    2000
    Co-Authors: David J. Perreault, V. Caliskan
    Abstract:

    This paper introduces a new design for Alternator systems that provides dramatic increases in peak and average power output from a conventional Lundell Alternator, along with substantial improvements in efficiency. Experimental results demonstrate these capability improvements. Additional performance and functionality improvements of particular value for highvoltage (e.g., 42 V) Alternators are also demonstrated. Tight load-dump transient suppression can be achieved using this new design and the Alternator system can be used to implement jump charging (the charging of the high-voltage system battery from a low-voltage source). Dual-output extensions of the technique (e.g., 42/14 V) are also introduced. The new technology preserves the simplicity and low cost of conventional Alternator designs, and can be implemented within the existing manufacturing infrastructure.

Li Wei Song - One of the best experts on this subject based on the ideXlab platform.

  • High-Efficiency Control Strategy of an Air-Core Pulsed Alternator Pair
    IEEE Transactions on Plasma Science, 2017
    Co-Authors: Xi Yuan Li, Li Wei Song
    Abstract:

    As an attractive power supply for high energy level pulsed power applications, such as long range electromagnetic railgun, electromagnetic aircraft launch system, and high-energy laser, multiple pulsed Alternators can not only meet the high energy level requirement of the load, but also lower the requirements of the power electronics in the system. Utilizing multiple pulsed Alternators work together also makes the control strategy of the system more flexible. In order to improve the efficiency of the whole system, a novel control strategy of an air-core pulsed Alternator pair is proposed in this paper. Like a single pulsed Alternator, the whole work process of the pulsed Alternator pair can also be divided into three subprocesses: the self-excitation process, the discharge process, and the energy reclamation process. In the self-excitation and energy reclamation processes, the armature windings of the pulsed Alternator pair are connected in series, and the filed windings are connected in parallel. In order to illustrate the advantages of this control strategy, a comprehensive discussion of different connection topologies of the Alternator pair has been made in this paper. A mathematical model based on the equivalent circuit of the air-core pulsed Alternator considering the harmonic components was also established in this paper, which could help calculating the system efficiency more accurately. The results and conclusions of the analyses and simulations can offer guidance for the air-core pulsed Alternator pair system design and optimization.

  • Impact Factors for Energy Reclamation Control of an Air-Core Pulsed Alternator
    IEEE Transactions on Applied Superconductivity, 2016
    Co-Authors: Xi Yuan Li, Li Wei Song
    Abstract:

    Thermal management of air-core pulsed Alternators is an important problem to be solved before the Alternators come to eventual deployment in mobile applications. The stator thermal problem is mainly caused by the armature winding heat generation and the rotor thermal problem is mainly caused by the field winding heat generation. Unlike the stator thermal management study, there is little literature about the rotor thermal management. So, the rotor thermal management remains a major challenge because of the poor conductivity of rotor material. Therefore, an energy reclamation control strategy was presented in this paper to reduce the heat generation of the field winding after discharge process. In the energy reclamation process, the self-excitation bridge starts to work again making the pulsed Alternator work as a motor and a portion of the electromagnetic energy stored in the field winding is converted to rotor kinetic energy. Because the heat loss is reduced, the efficiency of the whole system can be improved. The equivalent circuit topology that can realize the energy reclamation control was established. Based on the circuit topology, the factors impacted the energy reclamation efficiency were analyzed. The impact factors include not only control parameters but also design parameters of the Alternator. Under some assumptions, the optimal trigger angle was calculated. Conclusions that can offer guidance for the design and optimization of air-core pulsed-Alternator systems were also reached.

  • Study on the self-excitation condition of a two-phase air-core pulsed Alternator
    2015 IEEE International Conference on Applied Superconductivity and Electromagnetic Devices (ASEMD), 2015
    Co-Authors: Xi Yuan Li, Li Wei Song
    Abstract:

    As a new type of pulsed power supply, air-core pulsed Alternators concentrate all the functions of energy storage, energy conversion and power conditioning in one machine. It is also easy to condition the output voltage and current waveforms. These advantages make it a promising compact power supply system for a variety of fields including laser and electromagnetic launchers. The whole work process of a two-phase air-core pulsed Alternator can be divided into self-excitation process, discharge process and energy reclaim process. The aim of the self-excitation is to generate an adequate current in the exciting winding for the discharge process and there is a condition to realize a successful self-excitation for a two-phase air-core pulsed Alternator. In this paper, the relationship between the successful self-excitation condition and the design parameters of the air-core pulsed Alternator was established. A comparison of the successful self-excitation condition between a single-phase air-core pulsed Alternator and a two-phase Alternator was also made. To verify the conclusions of the paper, some simulations were performed on a single-phase air-core pulsed Alternator and a two-phase air-core pulsed Alternator. Each phase armature winding of the two-phase Alternator shares the same electrical parameters as the single-phase Alternator. The results and conclusions of the analyses and simulations in this paper can offer guidance for the flexible design and optimization of two-phase air-core pulsed Alternators.

  • Energy reclaim control of an air-core pulsed Alternator
    2015 IEEE International Conference on Applied Superconductivity and Electromagnetic Devices (ASEMD), 2015
    Co-Authors: Xi Yuan Li, Li Wei Song
    Abstract:

    Air-core pulsed Alternators have been under development for over 30 years, although a lot of progress has been made, there are still some problems to be solved before it comes to eventual deployment in mobile applications. One of the problems is the thermal management. The pulsed Alternator stator thermal management has been studied for more than 25 years. However, there is little literature about the energy reclaim control specifics, such as the control strategy of the reclaim process, and what are the factors affect the reclaim process. This paper presents an energy reclaim control strategy of the air-core pulsed Alternator. Under some assumptions, the optimal trigger angle was calculated, which can reclaim the electromagnetic energy stored in the field winding as quickly as possible. The energy reclaim control of the air-core pulsed Alternator can reduce the rotor heat generation. Therefore, it allows the use of the air-core pulsed Alternators beyond basic laboratory shot numbers. Because the heat loss is reduced, the reclaim control strategy can also improve the efficiency of the whole system. The analyses of the design parameters affecting reclaim efficiency were made and some conclusions which can offer guidance for the design and optimization of air-core pulsed-Alternator systems were reached.

Xi Yuan Li - One of the best experts on this subject based on the ideXlab platform.

  • High-Efficiency Control Strategy of an Air-Core Pulsed Alternator Pair
    IEEE Transactions on Plasma Science, 2017
    Co-Authors: Xi Yuan Li, Li Wei Song
    Abstract:

    As an attractive power supply for high energy level pulsed power applications, such as long range electromagnetic railgun, electromagnetic aircraft launch system, and high-energy laser, multiple pulsed Alternators can not only meet the high energy level requirement of the load, but also lower the requirements of the power electronics in the system. Utilizing multiple pulsed Alternators work together also makes the control strategy of the system more flexible. In order to improve the efficiency of the whole system, a novel control strategy of an air-core pulsed Alternator pair is proposed in this paper. Like a single pulsed Alternator, the whole work process of the pulsed Alternator pair can also be divided into three subprocesses: the self-excitation process, the discharge process, and the energy reclamation process. In the self-excitation and energy reclamation processes, the armature windings of the pulsed Alternator pair are connected in series, and the filed windings are connected in parallel. In order to illustrate the advantages of this control strategy, a comprehensive discussion of different connection topologies of the Alternator pair has been made in this paper. A mathematical model based on the equivalent circuit of the air-core pulsed Alternator considering the harmonic components was also established in this paper, which could help calculating the system efficiency more accurately. The results and conclusions of the analyses and simulations can offer guidance for the air-core pulsed Alternator pair system design and optimization.

  • Impact Factors for Energy Reclamation Control of an Air-Core Pulsed Alternator
    IEEE Transactions on Applied Superconductivity, 2016
    Co-Authors: Xi Yuan Li, Li Wei Song
    Abstract:

    Thermal management of air-core pulsed Alternators is an important problem to be solved before the Alternators come to eventual deployment in mobile applications. The stator thermal problem is mainly caused by the armature winding heat generation and the rotor thermal problem is mainly caused by the field winding heat generation. Unlike the stator thermal management study, there is little literature about the rotor thermal management. So, the rotor thermal management remains a major challenge because of the poor conductivity of rotor material. Therefore, an energy reclamation control strategy was presented in this paper to reduce the heat generation of the field winding after discharge process. In the energy reclamation process, the self-excitation bridge starts to work again making the pulsed Alternator work as a motor and a portion of the electromagnetic energy stored in the field winding is converted to rotor kinetic energy. Because the heat loss is reduced, the efficiency of the whole system can be improved. The equivalent circuit topology that can realize the energy reclamation control was established. Based on the circuit topology, the factors impacted the energy reclamation efficiency were analyzed. The impact factors include not only control parameters but also design parameters of the Alternator. Under some assumptions, the optimal trigger angle was calculated. Conclusions that can offer guidance for the design and optimization of air-core pulsed-Alternator systems were also reached.

  • a flexible waveform conditioning strategy of an air core pulsed Alternator
    IEEE Transactions on Plasma Science, 2015
    Co-Authors: Xi Yuan Li, Shaopeng Wu, Xin Zhao
    Abstract:

    As a new type of pulsed power supply, an air-core pulsed Alternator concentrates all the functions of energy storage, energy conversion, and power conditioning in one machine. It is also easy to condition the output voltage and current waveforms. These advantages make it a promising compact power supply system for the electrothermal-chemical gun (ETCG). However, the use of multiphase air-core pulsed Alternators as the power supply of ETCGs may give rise to problems such as generating high voltage trigger pulse and providing proper voltage and current waveforms. According to the special requirements of ETCGs, a novel circuit topology and a flexible waveform conditioning strategy of an air-core pulsed Alternator were proposed. In the initial stage of the discharge process, the two-phase armature windings are connected in series to generate a high voltage pulse to ignite the capillary. The series mode does not need a high-voltage capacitor and its charger to ignite the capillary, which makes the whole system more compact. After the capillary is ignited, the two-phase armature windings are connected in parallel. Adding conditioning inductors and controlling the trigger angles can make the voltage and current waveforms more flexible. The mathematical model of the two-phase air-core pulsed Alternator was established to obtain the basic relationship of the variables. Based on the mathematical model and the circuit topology, the performances of the ETCG powered by the Alternator using the flexible waveform conditioning strategy were analyzed. The results indicate that with the new strategy of the air-core pulsed Alternator it is feasible to provide more flexibility in pulse conditioning than with the conventional strategy.

  • Study on the self-excitation condition of a two-phase air-core pulsed Alternator
    2015 IEEE International Conference on Applied Superconductivity and Electromagnetic Devices (ASEMD), 2015
    Co-Authors: Xi Yuan Li, Li Wei Song
    Abstract:

    As a new type of pulsed power supply, air-core pulsed Alternators concentrate all the functions of energy storage, energy conversion and power conditioning in one machine. It is also easy to condition the output voltage and current waveforms. These advantages make it a promising compact power supply system for a variety of fields including laser and electromagnetic launchers. The whole work process of a two-phase air-core pulsed Alternator can be divided into self-excitation process, discharge process and energy reclaim process. The aim of the self-excitation is to generate an adequate current in the exciting winding for the discharge process and there is a condition to realize a successful self-excitation for a two-phase air-core pulsed Alternator. In this paper, the relationship between the successful self-excitation condition and the design parameters of the air-core pulsed Alternator was established. A comparison of the successful self-excitation condition between a single-phase air-core pulsed Alternator and a two-phase Alternator was also made. To verify the conclusions of the paper, some simulations were performed on a single-phase air-core pulsed Alternator and a two-phase air-core pulsed Alternator. Each phase armature winding of the two-phase Alternator shares the same electrical parameters as the single-phase Alternator. The results and conclusions of the analyses and simulations in this paper can offer guidance for the flexible design and optimization of two-phase air-core pulsed Alternators.

  • Energy reclaim control of an air-core pulsed Alternator
    2015 IEEE International Conference on Applied Superconductivity and Electromagnetic Devices (ASEMD), 2015
    Co-Authors: Xi Yuan Li, Li Wei Song
    Abstract:

    Air-core pulsed Alternators have been under development for over 30 years, although a lot of progress has been made, there are still some problems to be solved before it comes to eventual deployment in mobile applications. One of the problems is the thermal management. The pulsed Alternator stator thermal management has been studied for more than 25 years. However, there is little literature about the energy reclaim control specifics, such as the control strategy of the reclaim process, and what are the factors affect the reclaim process. This paper presents an energy reclaim control strategy of the air-core pulsed Alternator. Under some assumptions, the optimal trigger angle was calculated, which can reclaim the electromagnetic energy stored in the field winding as quickly as possible. The energy reclaim control of the air-core pulsed Alternator can reduce the rotor heat generation. Therefore, it allows the use of the air-core pulsed Alternators beyond basic laboratory shot numbers. Because the heat loss is reduced, the reclaim control strategy can also improve the efficiency of the whole system. The analyses of the design parameters affecting reclaim efficiency were made and some conclusions which can offer guidance for the design and optimization of air-core pulsed-Alternator systems were reached.