* Prepared by Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Dept. of Energy under contract DE-AC05-00OR22725. The submitted manuscript has been authored by a contractor of the U.S. Government under contract DE-AC05-00OR22725. Accordingly, the U.S. Government retains a nonexclusive, royalty-free license to publish or reproduce the published form of this contribution, o...

This work have studied and developed lifetime estimation methods for the power transformer and how these could be used for asset management purposes. It is research performed in the intersection of the fields of reliability theory, statistical analysis, and stochastic process theory applied to lifetime estimations and management of transformers. The chosen approaches are the following. The thes...

The paper presents common mode voltage analysis of single phase grid connected photovoltaic inverter. Many researchers proposed different grid tie inverters for applications like domestic powering, street lighting, water pumping, cooling and heating applications. Traditional grid tie PV inverter uses either a line frequency or a high frequency transformer between the inverter and grid. The tran...

In applications for high-Tc superconducting DC-SQUIDs such as biomagnetism, nondestructive evaluation and the relaxation of magnetic nanoparticles, it is important to maintain reliable sensor performance over an extended time period. We designed and produced DC-SQUID gradiometers based on YBa2Cu3O7−x (YBCO) thin films which are inductively coupled to a flux transformer to achieve a higher sensi...

Legacy transformers are passive, bulky, becoming expensive, and take longer time to deliver. They cannot provide the power quality or control which today’s loads demand for proper functioning and the electric system needs for its survivability. Solid-state transformers have been promising technologies in recent years. EPRI is pursuing development of an innovative solution – the IUTTM (Intellige...

A new method to improve the dynamic response of power-factor correctors (PFC’s) is described in this paper. The method is based on the use of a new very highly efficient postregulator, called a series-switching postregulator. This new postregulator exhibits very high efficiency due to the fact that only a part of the total power undergoes a power conversion process. The proposed postregulator c...

The condition of the internal cellulosic paper and oil insulation are of concern for the performance of power transformers. Over the years, a number of methods have been developed to diagnose and monitor the degradation/aging of the transformer internal insulation system. Some of this degradation/aging can be assessed from electrical responses. Currently there are a variety of electrical-based ...

—Field experience indicates that ferroresonance events occur more readily with low-loss distribution transformers, compared to distribution transformers with conventional loss levels. Extensive testing of a large number of transformers has shown a very strong and direct correlation between transformer core loss and the amount of capacitance needed to sustain a ferroresonant condition. A heurist...

This paper considers the history of oscillating water column (OWC) systems from whistling buoys to grid-connected power generation systems. The power conversion from the wave resource through to electricity via pneumatic and shaft power is discussed in general terms and with specific reference to Voith Hydro Wavegen’s land installed marine energy transformer (LIMPET) plant on the Scottish islan...