In recent years, renewable energy sources have been integrated on a large scale in power systems all around the world to address environmental sustainability concerns. With conventional thermal generators being phased out, offshore wind plants present viable alternative provide blackstart services for system restoration. By means of simulations, grid-forming turbines are shown successfully ener...

Transformer model; Load flow analysis; Symmetrical components; Distribution systems Abstract This paper presents an efficient approach for developing three-phase transformer admittance matrices in the radial power-flow analysis. The proposed transformer model overcomes the singularity problem of the nodal admittance submatrices of ungrounded transformer configurations. This has been achieved by...

The present paper deals with the analysis and development of noise-reduction transformer that has a filter function for conductive noise transmission. Two types of prototype noise-reduction transformers with two different output voltages are proposed. To determine an optimum design for the noise-reduction transformer, noise attenuation characteristics are discussed based on the experiments and ...

a wind turbine transformer (wtt) is designed using a 3d wound core while the transformer’s total owning cost (toc) and its inrush current performance realized as the two objective functions in a multi-objective optimization process. multi-objective genetic algorithm is utilized to derive pareto optimal solutions. the effects of inrush current improvement on other operating and design parameters...

this work studies the effect of neutral earth resistance on the controlling ferroresonance oscillation in the power transformer including MOV surge arrester. A simple case of ferroresonance circuit in a three phase transformer is used to show this phenomenon and the three-phase transformer core structures including nonlinear core losses are discussed. The effect of MOV surge arrester and neutra...

Power system overvoltages due to switching, lightning and other disturbances are the main problem for designers of the power transformers. Once some frequencies of the incoming surges match with some of the natural frequencies of transformer winding, the resonance phenomenon is expected in transformer winding. The resonant overvoltages may destroy the insulation between turns and cause to insul...

It is important to monitor the moisture content of transformer oil in a transformer. One parameter of particular interest is the moisture solubility of transformer oil. It has been reported that transformer oils under different conditions have different solubility. Measurements of solubility for four different types of conditioned oil are presented in this paper: fresh Shell Diala AX oil, lab-a...

The metabolic changes in rat hepatoma cell line, AH70 cells, after coculturing with Kupffer cells were visualized using a silicon-intensified target camera and subsequent processing with a computer-assisted digital imaging processor. In cocultured tumor cells, nonactivated Kupffer cells reduced mitochondrial energization as indicated by the decrease in the fluorescence intensity of rhodamine 12...