A novel stator doubly fed doubly salient permanent magnet brushless machine

In this paper, a novel stator doubly fed doubly salient-permanent magnet (SDFDS-PM) brushless machine topology is proposed, which not only reduces both PM material and field winding MMF significantly, but also offers the distinct advantage of wide constant-power operation range (namely, 4 times the base speed) which is essential for electric vehicle application.published_or_final_versio

A Novel Stator Doubly Fed Doubly Salient Permanent Magnet Brushless Machine

A novel stator doubly fed doubly salient permanent magnet (PM) brushless machine is proposed. The novelty of this machine is to purposely add an extra flux path in shunt with each PM pole, hence amplifying the effect of flux weakening for constant power operation. Magnetic circuit analysis is adopted to illustrate the novelty. Machine flux paths and performance curves determined by a finite-element analysis are presented for various excitations. The corresponding results show that the proposed machine is promising for application to electric vehicles.published_or_final_versio

Transient analysis of a new outer-rotor permanent-magnet brushless DC drive using circuit-field-torque coupled time-stepping finite-element method

In this paper, a new outer-rotor permanent magnet (PM) brushless dc drive is designed and analyzed. To enable this drive applicable to electric vehicles, its transient performances at both normal and flux-weakening operations are particularly focused. The distinct feature in design is due to the new motor configuration including the outer-rotor topology, the multipole magnetic circuit and the full slot-pitch coil span arrangement. The distinct feature in analysis is due to the development of the circuit-field-torque coupled time-stepping finite-element method. The proposed PM brushless dc drive is prototyped. The analysis results are verified by experimental measurement.published_or_final_versio

Design and analysis of a new multiphase polygonal-winding permanent-magnet brushless dc machine

In this paper, a new multiphase polygonal-winding permanent-magnet brushless dc (PMBDC) machine is proposed anal analyzed. The originality of the proposed machine lies on the multiphase polygonal-winding stator anal the surface-inset permanent-magnet rotor. Because of its unique structure and operating principle, a circuit-field-torque coupled time stepping finite-element method is also employed for analysis. The designed machine is prototyped and the analysis is verified by experimentation.published_or_final_versio

Design and analysis of magnet proportioning for dual-memory machines

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A novel polyphase multipole square-wave permanent magnet motor drive for electric vehicles

A novel high-power-density permanent magnet (PM) motor drive for electric vehicles (EVs) is proposed. The motor is a polyphase multipole square-wave PM motor, which can be classified as a kind of PM brushless DC motor. The distinct features of the proposed motor as compared to those of the conventional PM brushless DC motor are as follows. First, the multipole magnetic circuit arrangement enables the minimization of the magnetic yoke, resulting in the reduction of motor volume and weight. Second, the coil span is purposely designed to be equal to one slot pitch, thus saving the amount of copper used. Third, by using a fractional number of slots per pole per phase, the arrangement of the numbers of poles and slots is so unique that the magnetic force between the stator and the rotor at any rotating position is uniform, hence eliminating the cogging torque that usually occurs in PM motors. Finally, the motor can be controlled to operate at a constant torque region and a constant power region with field weakening, thus both high starting torque and high cruising speed can be achieved. Therefore, as the proposed motor drive possesses the distinct advantages of high power density, high efficiency, and superior dynamic performance, it is very suitable for EV applications. A prototype of a five-phase 22-pole 5 kW motor drive has been designed for an experimental EV.published_or_final_versio

Scalar control of a new phase-decoupling permanent magnet synchronous motor for servo application

This paper presents a new scalar-controlled phase-decoupling permanent magnet synchronous motor (PD-PMSM) which takes the advantages of smooth torque, fast response and good controllability for servo applications. Because of the PD nature, the proposed scalar control strategy can simply adjust the phase current amplitude and its angle with respect to the back EMF to achieve direct torque control. Experimental results are given to verify the advantages of the proposed scalar-controlled PD-PMSM. © 2005 IEEE.published_or_final_versio

QoSS Hierarchical NoC-Based Architecture for MPSoC Dynamic Protection

As electronic systems are pervading our lives, MPSoC (multiprocessor system-on-chip) security is becoming an important requirement. MPSoCs are able to support multiple applications on the same chip. The challenge is to provide MPSoC security that makes possible a trustworthy system that meets the performance and security requirements of all the applications. The network-on-chip (NoC) can be used to efficiently incorporate security. Our work proposes the implementation of QoSS (quality of security service) to overcome present MPSoC vulnerabilities. QoSS is a novel concept for data protection that introduces security as a dimension of QoS. QoSS takes advantage of the NoC wide system visibility and critical role in enabling system operation, exploiting the NoC components to detect and prevent a wide range of attacks. In this paper, we present the implementation of a layered dynamic security NoC architecture that integrates agile and dynamic security firewalls in order to detect attacks based on different security rules. We evaluate the effectiveness of our approach over several MPSoCs scenarios and estimate their impact on the overall performance. We show that our architecture can perform a fast detection of a wide range of attacks and a fast configuration of different security policies for several MPSoC applications

Measurements of Cabibbo Suppressed Hadronic Decay Fractions of Charmed D0 and D+ Mesons

Using data collected with the BESII detector at $e^{+}e^{-}$ storage ring Beijing Electron Positron Collider, the measurements of relative branching fractions for seven Cabibbo suppressed hadronic weak decays $D^0 \to K^- K^+$, $\pi^+ \pi^-$, $K^- K^+ \pi^+ \pi^-$ and $\pi^+ \pi^+ \pi^- \pi^-$, $D^+ \to \bar{K^0} K^+$, $K^- K^+ \pi^+$ and $\pi^- \pi^+ \pi^+$ are presented.Comment: 11 pages, 5 figure