Expert in Electronic Drive/Power Quality
A significant portion of Expert's career in the design of drives has involved the optimization of single- and three-phase induction motor drives with respect to efficiency for given constraints (costs, performance characteristics). Comparison of several constrained optimization techniques involving nonlinear programming approaches lead to similar solutions. It can be expected that such optimal design techniques will be heavily used due to the recent passage of the Energy Policy Act of 1992.
Within the emerging field of power quality in power systems, Expert is an expert in the analysis of the generation, propagation, mitigation, and prevention of harmonics and fractional harmonics in distribution systems. He uses fundamental Newton-Raphson type load flow, harmonic load flow (HARMFLO), and the electromagnetic transients program (EMTP). He studied impacts of voltage and current harmonics on power system components and end-use devices as well as the effects of geomagnetically induced currents in power systems.
In his design and development work, Expert routinely uses nonlinear magnetic field analysis such as finite element and finite difference methods in two and three dimensions. Applications of such methods include induction, synchronous, permanent-magnet, and homopolar machines; linear and rotary motion electromechanical actuators, magnets, and inductors. These numerical methods solve the linear and nonlinear Laplace, Poisson, and the diffusion equations, that is, magnetostatic as well as electrodynamic field problems.
Expert's most recent work concerns improvement of the seasonal energy efficiency ratio (SEER) of heat pumps and the design of variable-speed wind power plants, hybrid electric cars with recovery of braking energy, and of high-efficiency electric motors and drives exploiting permanent magnets. New materials such as compressed powdered iron cores are employed. Energy conservation is possible through motor efficiency improvement, distribution system power factor correction, mechanical system and motor matching with adjustable-speed drives, and process optimization.
Expert has designed pulse-width-modulated inverters and rectifiers and their simulation with SPICE. He has dealt with reverse-recovery currents of diodes and transistors and their suppression. Gating circuits with either transformer or optical coupling has been applied to single- and three-phase systems where the gating pulses are synchronized with an external periodic signal via a voltage-controlled oscillator. Control of inverters is made such that these devices can continuously change the power factor and waveshape of the output current.
Expert has consulted with numerous businesses concerning application of electric machines, transformers, and actuators. He has resolved issues related to rewinding of electric machines, harmonic currents in the neutrals of transformers, and application of induction motors within bore holes. Electronically commutated DC, stepper, and switched reluctance motors, field-oriented control, and field weakening appear to be of recurring importance. He has advised on design of magnetic couplings and electromagnetic actuators consisting of permanent-magnet and voice coil, as well as torque motors.
Most electric quantities encountered are nonsinusoidal, Expert maintains, so conventional analog metering is not possible. With the emergence of flexible PCs, analog to digital (A/D) and digital to analog (D/A) converters as well as programmable arbitrary waveform generators, the measurement of nonsinusoidal/sinusoidal quantities can be preformed based on 12 to 16 bit sampled data acquisition networks. Expert has gained considerable laboratory experience through recent research and development work at the University of Colorado with respect to on-line monitoring of transformer losses and derating.
Expert may consult nationally and internationally, and is also local to the following cities: Denver, Colorado - Colorado Springs, Colorado - Aurora, Colorado - Fort Collins, Colorado - Arvada, Colorado - Westminster, Colorado - Boulder, Colorado - Greeley, Colorado - Longmont, Colorado - Cheyenne, Wyoming
|Year: 1970||Degree: PhD||Subject: Electrical Engineering||Institution: University of Colorado - Boulder|
|Year: 1967||Degree: MS||Subject: Electrical Engineering||Institution: University of Stuttgart, Germany|
|Year: 1965||Degree: BS||Subject: Electrical Enginnering||Institution: University of Stuttgart, Germany|
|Years: 1979 to Present||Employer: Undisclosed||Title: Professor of Electrical Engineering||Department:||Responsibilities:|
|Years: 1971 to 1977||Employer:||Title: Senior Research and Development Engineer in Industry||Department:||Responsibilities:|
|Expert is a Fellow of the Institute of Electrical and Electronics Engineers. He is a reviewer of major technical journals in the fields of power systems, energy conversion, industry applications, and power electronics.|
|Awards / Recognition|
|He was awarded a paper prize in 1972 by the German Association of Electrical Engineers, the IEEE 1989 Prize Paper Award of the Power Engineering Society, and the IEEE 1989 Power System Relaying Committee Award.
|Publications and Patents Summary|
|He has published and presented about 100 technical papers in his chosen areas of energy conversion and control theory.|