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TL;DR: In this article, an unbalanced line-to-line current injection between two lines of the ac system was proposed to measure the impedance information in the traditional synchronous reference frame d-q model.
Abstract: Naval ships as well as aerospace power systems are incorporating a greater degree of power electronic switching sources and loads. Although these components provide exceptional performance, they are prone to instability due to their high efficiency and constant power characteristics that can exhibit negative impedance nature at certain frequencies. When designing these systems, integrators must consider the impedance versus frequency at an interface (which designates source and load). Stability criteria have been developed in terms of source and load impedances for both dc and ac systems, and it is often helpful to have techniques for impedance measurement. For dc systems, the measurement techniques have been well established. This paper introduces a new method of impedance measurement for three-phase ac systems. By injecting an unbalanced line-to-line current between two lines of the ac system, all impedance information in the traditional synchronous reference frame d-q model can be determined. For medium-voltage systems, the proposed technique is simpler and less costly than having an injection circuit for each phase. Since the current injection is between only two phase lines, the proposed measurement device can be used for both ac and dc interfaces. Simulation and laboratory measurements demonstrate the effectiveness of this new technique.
220 citations
TL;DR: In this paper, the authors suggest several methods for measuring ac impedance including utilization of power converters, wound-rotor induction machines, and chopper circuits, and demonstrate the effectiveness of the proposed methods on an example ac power system.
Abstract: Naval ships as well as aerospace power systems are incorporating an increasing amount of power electronic switching sources and loads. Although these power-electronics-based components provide exceptional performance, they are prone to instability due to their constant power characteristics that lead to negative impedance. When designing these systems, integrators must consider the impedance versus frequency at a power system interface (which designates source and load). Stability criteria have been developed in terms of source and load impedance for both dc and ac power systems, and it is often helpful to have techniques for impedance measurement. For dc power systems, the measurement techniques have been well established. This paper suggests several methods for measuring ac impedance including utilization of power converters, wound-rotor induction machines, and chopper circuits. Simulation and laboratory results on an example ac power system demonstrate the effectiveness of the proposed methods.
122 citations
TL;DR: In this paper, an energy finite element analysis (EFEA) formulation for computing the high frequency behavior of plate structures in contact with a dense fluid is presented, where heavy fluid loading effect is incorporated in the derivation of the EFEA governing differential equations and in the computation of the power transfer coefficients between plate members.
61 citations
TL;DR: In this paper, a hybrid method is developed for predicting the highfrequency vibration response of fluid-loaded cylindrical shells with periodic circumferential stiffeners, which includes added mass and radiation effects due to the surrounding exterior fluid medium.
46 citations
TL;DR: In this paper, an energy finite element analysis (EFEA) formulation for high frequency vibration analysis of stiffened plates under heavy fluid loading is presented, and the added mass effect and the radiation damping effect due to the fluid loading are incorporated in the derivation of the EFEA governing differential equations.
43 citations
Authors
Showing all 17 results
| Name | H-index | Papers | Citations |
|---|---|---|---|
| M. Belkhayat | 15 | 26 | 1229 |
| Kuangcheng Wu | 4 | 7 | 156 |
| Kelly B. Payne | 3 | 3 | 296 |
| Garrett S. Haltiwanger | 2 | 2 | 19 |
| R. McNeal | 2 | 2 | 18 |
| William F. Johnston | 1 | 1 | 3 |
| Dick Kitterman | 1 | 1 | 5 |
| Joshua Vicari | 1 | 1 | 2 |
| Paul Blessner | 1 | 1 | 3 |
| Mark Nelson | 1 | 1 | 3 |
| Steven L. Holcomb | 1 | 1 | 3 |
| Dave Tilman | 1 | 1 | 3 |
| Kuangcheng Wu | 1 | 1 | 18 |
| Jr. James C. Nelms | 1 | 1 | 4 |
| Charles Smith | 1 | 3 | 5 |