The harmonic problem in power systems is gaining more attention as incidences correlated with harmonics increase. Conventional passive filtering techniques for harmonic mitigation have inherent problems, and purely active filters have the disadvantages of higher costs and ratings. Hybrid active filters inherit the efficiency of passive filters and the improved...
With the increased attention on high efficiency and energy savings, power electronic energy conversion equipment is increasingly incorporated in all levels of the power system. The drawback of such equipment is the generation of nonsinusoidal currents in the power distribution network due to the nonlinear operation. Harmonic currents may distort...
Power quality has become an important concern to both electric utilities and
end users due to the increased use of non-linear loads in modem power systems
over the past decade. Nonlinear loads inject harmonics into the power system and
thus may lead to poor power quality and lower power factor....
With the increased attention on high efficiency and controllability of industrial processes, as well as reduced weight, volume and cost of consumer products, the applications of nonlinear power electronic converters such as adjustable speed drives (ASDs) are showing a rapid rise. Power Quality (PQ) is becoming an increasing concern with...
Synchronous machines provide a practical way to control reactive power consumption of a plant. One of the main advantages of using synchronous motors in a plant is their ability to generate reactive power for plant loads. A new control scheme for synchronous motor excitation systems is developed to automate reactive...
Advancements in power electronics to higher power levels and faster switching times allow new machine and systems designs, but also create higher stresses on electric machinery insulation. High performance, pulse-width modulated (PWM) inverters are now available for medium voltage drive systems, and are being considered by the U.S. Navy as...
With the development of high performance power electronic and semiconductor technologies, Adjustable Speed Drive (ASD) systems are increasingly applied in residential, commercial and industrial applications. Due to the advantages at higher power ratings, the three-level Neutral-Point-Clamped (NPC) Voltage Source Inverter (VSI) is being employed in industrial and traction applications, static...
Advanced low power devices promote the development of micro power generators (MPGs) to replace the batteries to power them. Due to the trend in decreasing integrated circuit (IC) supply voltages, power supply designers are facing more and more serious challenges. The objective of this research is to design a power...
Many new applications of energy system devices have been developed to save energy, improve the controllability and stability of industrial processes, and reduce the weight, volume and cost of consumer devices. Due to the novelty of these devices, traditional empirical methods and lumped-parameter circuit theory methods are not sufficient for...
Hybrid electric vehicles (HEV’s) are a very important part of today’s transportation system as they are bridging the gap between fully electric vehicles and conventional internal combustion vehicles (ICV’s). They have much higher efficiencies and lower emissions than ICV’s, while still having the ability to travel long range and refuel...