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Due to increasing demand on adequate dynamic load modeling, aggregation algorithms for induction and synchronous motors are proposed in the literature for cases that the same types of motors are connected to a common bus. However, one problem remains unsolved: how to perform load aggregation with upstream motors if both induction and synchronous motors are(More)
Medium-voltage drives (MVDs) are increasingly used in oil field facilities for high-power electrical submersible pump (ESP) wells. The load filter remains to be a critical component in such applications. In this paper, a load filter design method for MVD applications in ESP systems is proposed, which is suitable for various types of MVDs and with different(More)
The arc flash hazard is related to electrical safety in work place and has gained much attention as part of the safety program for many facilities. An effective approach to reducing the arc flash hazard in existing industrial and commercial facilities is proposed in this paper. To illustrate the proposed approach and provide quantified results, computer(More)
The greatest risk from live-attenuated vaccines is reversion to virulence. Particular concerns arise for RNA viruses, which exhibit high mutation frequencies. We examined the stability of 3 attenuation strategies for the alphavirus, Venezuelan equine encephalitis virus (VEEV): a traditional, point mutation-dependent attenuation approach exemplified by(More)
Venezuelan equine encephalitis virus (VEEV) has been responsible for hundreds of thousands of human and equine cases of severe disease in the Americas. A passive surveillance study was conducted in Peru, Bolivia and Ecuador to determine the arboviral etiology of febrile illness. Patients with suspected viral-associated, acute, undifferentiated febrile(More)
Two types of harmonics are investigated for induction motors: space harmonics and time harmonics. Space harmonics are generated due to the different phase windings interaction when the power supply is sinusoidal and they can be reduced by applying a proper machine design. As an example, the electromagnetic field and corresponding harmonics of an electrical(More)
Variable frequency drives (VFD) are widely used in industrial facilities, however, dynamic models for VFD-motor systems suitable for power system dynamic studies are not available. In this paper, a generic VFD-motor system modeling technique is proposed for the case that VFDs are able to ride through the fault. To illustrate the proposed technique, a(More)
Direct current (dc) motor drive systems are extensively used in paper, steel, mining, material handling, and other industrial applications due to the high starting torque and easy speed control over a wide range. They could account for 10%-20% load demand in some industrial facilities and thus have significant impact on the overall system dynamics. However,(More)