Pamela Newman

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Underground mining is characterized by space constraints forcing the use of long cables to feed large machines, where the application of variable speed drives can generate overvoltages at the machine terminals. This paper presents the analysis and mitigation of harmful overvoltages detected in inverter-fed 1400-hp 13.8-kV motors used for air ventilation in(More)
High-power pulsewidth-modulated inverters for medium-voltage applications operate at switching frequencies below 1 kHz to keep the dynamic losses of the power devices at a permitted level. Also, the sampling rate of the digital signal processing system is then low, which introduces considerable signal delays. These have adverse effects on the dynamics of(More)
Grinding mill drives play an important role in the mining industry. Almost 60% of the electrical energy consumed by modern concentrator plants goes to grinding mill drives. Different technologies are used in grinding systems presenting special characteristics from the electrical and process points of view. This paper presents a technical evaluation and(More)
The use of three-level neutral-point-clamped (3L-NPC) voltage source inverters for drive applications in the megawatt range is becoming a standard solution. In combination with the same converter circuit in rectifier operation as active front end (AFE), four-quadrant operation is also available. An existing plant, which has been in operation with eight(More)
High-power converters for regenerative drives and distributed generation need a network-friendly operation with low switching frequency for high reliability and performance. This paper presents a multipulse connection of two three-level NPC PWM rectifiers with the selective harmonics elimination technique (SHE) and a novel optimal method for minimal current(More)
Mining systems have complex power networks including high-power equipment, variable configuration and distributed harmonic injections. This paper presents the problem of resonance mitigation and dynamical behavior of a power system with harmonic filters (HF) for improving reliability in mining plants. It is known that the main objective of the harmonic(More)
Recent years have seen an increased recognition of the role of the human operator in both the development and use of military systems. Human Factors Integration (HFI), the structured management process for ensuring the capture and accommodation of human capabilities and limitations in design has, however, a mixed record of success within military system(More)
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