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...

Major changes to the Next Linear Collider (NLC) design were facilitated by the experimental testing of the 75 MW X-band klystron at a 3.0 μsec pulse width 1 and new component development allowing the delay line distribution system (DLDS) to operate with eight bins instead of four. This change has a direct effect on the design of the klystron modulator. The general approaches, which are being st...

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...

The paper investigates the behavior of four transformer models in electromagnetic transients programs (EMTP) when calculating inrush currents due to shell-type transformers energization. These models are single-phase Saturable Transformer (STC), BCTRAN, Hybrid Transformer (XFMR) and UMEC. The measurements of a real transformer energization performed by EDF in France are used to evaluate the acc...

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 Drosophila transformer-2 gene uses alternative promoters and splicing patterns to generate four different mRNAs that together encode three putative RNA-binding polypeptides. The transformer-2 products expressed in somatic tissues function to regulate the RNA splicing of the sex determination gene doublesex, whereas products expressed in the male germ line play an unknown, but essential, rol...

The behavior of three phase five leg transformer under voltage sag is studied in this paper. This paper proposes a simple, practical model of a three phase-five leg, saturated transformer with accurate performance. Transformer saturation is produced when the voltage sag is recovered and it causes inrush current in transformer. Effects of voltage sag depth, duration and initial point on wave hav...

Transformer inrush currents are highmagnitude, harmonic-rich currents generated when transformer cores are driven into saturation during energization. These currents have undesirable effects, including potential damage or loss-of-life to the transformer, protective relay misoperation, and reduced power quality on the system. Controlled transformer switching can potentially eliminate these trans...

Polarization and Depolarization Current (PDC) testing is a non-destructive dielectric testing method to determine the conductivity of insulations. It is one of the dielectric d iagnostic techniques based on time domain measurement. PDC measurement technique has gained immense popularity due to its ability to assess the condition of HV insulation. PDC measurement can provide information about th...