Engineering Commons^™

Enabling Wind Turbine Generators To Participate In Power Grid Frequency Regulation For Enhanced Stability, Hongtao Ma

Doctoral Dissertations

"This dissertation focuses on wind farm frequency regulation capability to maintain the grid frequency stability. Wind plant power controllers are designed and tested for participation in grid frequency restoration. The small signal stability on sub-optimal operating points is analyzed and a de-loaded operating point is proposed.

In the first paper, a new frequency regulation scheme is developed for the wind turbine/generator/converter trio that will provide the capability to participate in restoring frequency in a way similar to the droop response of conventional generators. Output active power adjustment can be realized by both converter and pitch angle control in addition to …

Energy Efficient Wireless Sensor Network Protocols For Monitoring And Prognostics Of Large Scale Systems, James W. Fonda

Doctoral Dissertations

"In this work, energy-efficient protocols for wireless sensor networks (WSN) with applications to prognostics are investigated. Both analytical methods and verification are shown for the proposed methods via either hardware experiments or simulation. This work is presented in five papers. Energy-efficiency methods for WSN include distributed algorithms for i) optimal routing, ii) adaptive scheduling, iii) adaptive transmission power and data-rate control"--Abstract, page iv.

System And Ic Level Analysis Of Electrostatic Discharge (Esd) And Electrical Fast Transient (Eft) Immunity And Associated Coupling Mechanisms, Jayong Koo

Doctoral Dissertations

"The exposure of electronic circuits to lightning, electrostatic discharge (ESD), electrical fast transients (EFT) or sine wave signals can reveal RF immunity problems. Typical problems include temporary malfunctions or permanent damage of integrated circuits (ICs). In an effort to reproduce those disturbances, a series of electromagnetic compatibility standards has been developed. However, a complete understanding of the root cause of the immunity problems has yet to be established. This dissertation discusses immunity problems in three papers, starting at the system level, via the coupling path into the IC"--Abstract, page iv.

Multiple-Input Multiple-Output Wireless Communications With Imperfect Channel Knowledge, Christopher Potter

Doctoral Dissertations

"In the first work a recurrent neural network (RNN) is employed for MIMO channel prediction. A novel PSO-EA-DEPSO off-line training algorithm is presented and is shown to outperform PSO, PSO-EA, and DEPSO. This predictor is shown to be robust to varying channel scenarios. New expressions for the received SNR, array gain, average probability of error, and diversity gain are derived. Next, a new expression for the outage capacity of a MIMO system with no CSI at the transmitter and an estimate at the receiver is presented. Since the outage capacity is a function of the first and second moments of …

Inter-Area Oscillation Damping In Large Scale Power Systems With Unified Power Flow Controllers, Mahyar Zarghami

Doctoral Dissertations

"Power system oscillations occur in power networks as a result of contingencies such as faults or sudden changes in load or generation. They are detrimental to the operation of the system since they affect system stability and the optimal power flow through it. These oscillations do not usually damp out in tie-lines unless certain controls are applied to the system. Local and inter-area oscillations have traditionally been controlled by Power System Stabilizers (PSS). However, Flexible Alternating Current Transmission Controllers (FACTS) have significant potential as alternatives to PSS. The main goal of this research is to damp inter-area oscillations by Unified …