Sharif Digital Repository

In this paper some advantage of online monitoring in power transformer and the sensors that can be used for partial discharge detection are described. Several detected PD in one power transformer and one distribution transformer are depicted. Matlabs wavelet package is employed to de-noise the recorded signals. As it appear from the captured and the denoised signals, PD signals in an aged power transformer are often enough large that can be easily detected through the noisy measured signals. By examination of the frequency spectrum of several PD signal in this paper it is obvious that this signal contain two major frequency band, one under 1 MHz and the other one between 7 to 9 MHz. © 2008... 

Deployment of renewable energies for the electricity generation is on the rise around the world, among which is the run-of-the-river (ROR) power plant whose output power is variable throughout the year depending on the water flow of the respective river. The inherent uncertainty associated with renewable energy resources calls for new stochastic modeling approaches to measure the impacts of using these energies on the power system performance. This paper develops an analytical reliability model for ROR power plants. The model is based on the state-space analysis and is devised with the intention of being used in adequacy studies of power systems. Failure of related components and the...