We propose load noise analysis components for small core-form transformers (1 MVA-20 MVA) using computational fluid-structure coupled calculations that consider the electromagnetic force, transformer structure and fluid (oil). The proposed technique has two beneficial aspects: coil modeling using shell elements of the finite element method (FEM), and acoustic noise analysis using a combination of boundary element method transmission path simulation and FEM structural simulation. The shell element model, which includes structural bending information, is less computationally intensive for simulations than solid models because it uses larger element sizes. Lighter simulations enable easier redesign for noise reduction. Additionally, division of the simulation process into individual structural vibrations, transmission paths, and radiation processes makes it easier to find a remodeling point without performing a complete simulation. We illustrate the importance of avoiding coincidence of the natural frequencies of the coils and the electromagnetic force and present a practical noise reduction study. This technique can be implemented using a light simulation that was proposed to confirm the remodeling effects. Using the proposed analysis method along with a ray tracing method, we can construct a frontloading design simulation tool to determine the transformer specifications and the substation's geographical features.

High-voltage equipment representing a tall and slender system is quite common. Capacitor racks and valve towers are common examples of such equipment. A representative example of such equipment is analyzed in this paper. Due to electrical isolation purposes, this type of equipment is usually comprised of brittle porcelain insulators or polymer insulators with low damping. The insulators are used as columns, main load carrying elements. The system is relatively tall and slender. Because of the large masses installed at various elevations of the system and the narrow footprint in one of the horizontal directions, the system has a relatively low resonant frequency. Seismic protection of such systems with a potentially large overturning moment and low resonant frequency is quite challenging. For example, a regular seismic isolation has limited use. To improve the seismic performance of the system, friction dampers are introduced into the system. The friction dampers are studied extensively in full-scale component tests, as it is required by the current draft of the IEEE693 document. The results of component tests are used in the development of a numerical finite element model, which is subjected to an IEEE693-spectrum compatible strong motion to evaluate the seismic performance of the seismically protected system.

The verification of the seismic performance of the power system equipment should be performed simulating the conditions experienced by the equipment when in service. Stresses on the porcelain of high voltage switchgear under seismic vibration are statically biased by internal pressure. However, restrictions from the seismic test facility pose some difficulties in practical procedure of test with pressure.This paper discusses the effect of pressure on the strain and proposes an equivalent test method to simulate a pressurized condition without actually filling the SF6 gas to the operating pressure.

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