In this paper, a model-based predictive framework is proposed to optimize the operation and maintenance actions for power system equipment which operates in a changing environment of the future grid. In this framework, a predictive health model is proposed that predicts the health state of this equipment based on its operation and maintenance actions. In particular, this framework is used to pr...

In this paper, a new model based on the thevenin equivalent circuit for investigating the ultra-saturation phenomenon during the energization of a loaded power transformer is presented and its effect on the differential protection of the transformer is considered. The ultra-saturation phenomenon causes the mal-operation of the power transformer differential protection. So, the description a...

Effect of an addition of a cooled step-up transformer to a flux locked loop (FLL) circuit was studied to reduce indirect rf interference to HTS-dc-SQUID. First, we demonstrated that a noise level of an HTS-dcSQUID system using the FLL circuit with single room-temperature transformer could be easily degraded by radiation of rf electromagnetic wave to cables in the FLL circuit. It is thought that...

This paper presents some techniques for reduction of transformer inrush current. The equation of inrush current is obtained and then by using these methods, transformer inrush current is reduced, then after comparing the result of each method, the best choice is determined. Results which have been obtained from EMTP simulation confirm these subjects.

This paper discusses design and simulation of dynamic voltage restorer for improve power quality & reduce the harmonics distortion of sensitive load. Electronics devices are very sensitive load against harmonics. DVR proposed not only to improve PQ but also to reduce HD due to the presence of non-linear load. The DVR consists of injection transformer, filter, ESS, VSI and control system. The ba...

Transformers are normally designed and built for use at rated frequency and sinusoidal load current. A non-linear load on a transformer leads to harmonic power losses which cause increased operational costs and additional heating in transformer parts. It leads to higher losses, early fatigue of insulation, premature failure and reduction of the useful life of the transformer. To prevent these p...

Protection systems have vital role in network reliability in short circuit mode and proper operating for relays. Current transformer often in transient and saturation under short circuit mode causes mal-operation of relays which will have undesirable effects. Therefore, proper and quick identification of Current transformer saturation is so important. In this paper, an Artificial Neural Network...