Patent Damage Strategies and the Enterprise License: Constructive Notice, Actual Notice, No Notice

For the patent owner, early provision of patent notice can help maximize recoverable infringement damages during subsequent litigation. This iBrief recognizes a growing trend of infringement suits predicated on patented enterprise software technology, and analyzes application of patent notice principles against industry convention. This iBrief examines the licensing paradigm of enterprise software and questions whether mechanical compliance with the marking statute should qualify as constructive notice. Borrowing from analogous Federal Circuit principles, this iBrief concludes by proposing alternate notice theories that would empower patentees to seek increased remedies consistent with industry reality, case law, and fundamental statutory purpose

Field-weakening performance of interior permanent-magnet motors

Copyright © 2002 IEEEThis paper compares the field-weakening performance under rated and overload conditions of synchronous reluctance and interior permanent-magnet motors against that of a baseline 2.2-kW induction machine. Four prototype rotors based on axially laminated and multiple-barrier designs were built and tested in the same induction machine stator. Field-weakening performance was estimated based on 50-Hz load tests at reduced voltage. It was found that the performance of the axially laminated synchronous reluctance machine was comparable with the induction machine while the interior permanent-magnet motors offered significantly better output power above rated speed. The multiple-barrier interior permanent-magnet motor design gave the most promising field-weakening performance.Wen L. Soong and Nesimi Ertugru

Inverterless high-power interior permanent-magnet automotive alternator

This paper describes a high-power brushless interior permanent-magnet (PM) automotive alternator which does not use an inverter. The “inverterless” alternator is designed with a high back electromotive force voltage and high reactance, and acts as a constant current source over much of its wide constant power operating speed range. In this configuration, a switched-mode rectifier can be used to regulate the dc output voltage and current, which avoids the complexity and high cost of an inverter. An analysis of the modeling and performance of interior PM machines in this inverterless topology is described. Experimental results showing an outstanding constant power speed range are presented for a 6-kW concept demonstrator machine tested using a three-phase resistive load to simulate inverterless operation.Wen L. Soong and Nesimi Ertugru

Detection and remediation of switch faults on a fault tolerant permanent magnet motor drive with reduncancy

Copyright © 2007 IEEE. All Rights Reserved.Fault-tolerant motor drives are becoming more important in safety critical applications. Using a special motor design and an appropriate inverter topology, brushless permanent magnet AC motor drives can have a fault-tolerant capability. This paper considers a dual motor drive system on a common shaft to introduce redundancy. The paper provides a systematic classification for the potential electrical faults which may occur in a real motor drive. In the paper, the switch and winding short circuit fault detection and identification methods are studied and experimental results are presented. In addition, the effects of switch faults on the phase currents and output torque are discussed, and remedial strategies for these faults are proposed. Furthermore, it was also demonstrated using simulation results that the proposed remedial strategies can compensate for the loss of torque due to the switch faults and can keep the peak-to-peak torque ripple factor comparable to healthy operation of the drive.Jingwei Zhu; Ertugrul, N.; Wen Liang Soon

On Internal Fracture of Solids

Initiation and propagation of internal fracture in solid

Investigation of effective automatic recognition systems of power-quality events

Copyright © 2007 IEEE. All Rights Reserved.There is a need to analyze power-quality (PQ) signals and to extract their distinctive features to take preventative actions in power systems. This paper offers an effective solution to automatically classify PQ signals using Hilbert and Clarke Transforms as new feature extraction techniques. Both techniques accommodate Nearest Neighbor Technique for automatic recognition of PQ events. The Hilbert transform is introduced as single-phase monitoring technique, while with the Clarke Transformation all the three-phases can be monitored simultaneously. The performance of each technique is compared with the most recent techniques (S-Transform and Wavelet Transform) using an extensive number of simulated PQ events that are divided into nine classes. In addition, the paper investigates the optimum selection of number of neighbors to minimize the classification errors in Nearest Neighbor Technique.Gargoom, A.M.; Ertugrul, N.; Soong, W.L

Minimum torque ripple current control strategy in dual fault tolerant PM AC motor drive

Copyright © 2008 IEEEIn this paper a dual fault tolerant motor drive utilizing brushless permanent magnet AC motors is investigated for safety critical applications. The motor modules are designed to provide both magnetic and electrical isolation between the phases, and the use of two modules also offers redundancy. This paper addresses an important issue, torque ripple and torque compensation due to the loss of a phase or phases in a practical dual motor drive. The mathematical models for reference current calculation in both healthy and various faulty operation modes are established under the zero torque ripple factor and minimum copper loss constraint conditions. These models are suitable for both sinusoidal and trapezoidal fault tolerant motor drives. The experimental results under various fault conditions are provided to verify the proposed fault remedial strategy.Jingwei Zhu, Nesimi Ertugrul, and Wen Liang Soon

Fault analysis and remedial strategies on a fault-tolerant motor drive with redundancy

Copyright © 2007 IEEEFault-tolerant motor drives are required in a range of safety-critical applications. Using a special motor design and an appropriate inverter topology, brushless permanent magnet AC motor drives can have an effective fault-tolerant capability. Although a single motor fault-tolerant drive system may be sufficient in many critical applications, a higher degree of fault tolerance requires redundancy in the motor system as considered in this paper. This is achieved by using a dual motor module on a common shaft. The simulation model of the entire drive system and the analysis of the various faults are presented in this paper. The effects of fault(s) on the phase current and output torque are provided. Three remedial operating modes are proposed and their features are compared. In addition, an experimental setup was introduced, which is based on dual electrically and magnetically isolated brushless AC motor modules, H-bridge inverters for individual phases and dsPICDEM MCU motor controller. © 2007 IEEE

Automatic classification and characterization of power quality events

Copyright © 2008 IEEEThis paper presents a new technique for automatic monitoring of power quality events, which is based on the multiresolution S-transform and Parseval's theorem. In the proposed technique, the S-transform is used to produce instantaneous frequency vectors of the signals, and then the energies of these vectors, based on the Parseval's theorem, are utilized for automatically monitoring and classification of power quality events. The advantage of the proposed algorithm is its ability to distinguish different power quality classes easily. In addition, the magnitude, duration, and frequency content of the disturbances can be accurately identified in order to characterize the disturbances. The paper provides the theoretical background of the technique and presents a wide range of analyses to demonstrate its effectiveness.Ameen M. Gargoom, Nesimi Ertugrul and Wen. L. Soon