The development of power electrical systems causes attention to accuracy of protection elements and measurement values. So we need some new measuring devices with high accuracy for power transmission lines. One of these devices is Optical Current Transformer (OCT). Optical current transformers are suitable for power system protection and can replace the magnetic current transformers. In this pa...

Low-power dichroic halogen lamps, usually used for display lighting, have low-voltage filament. The lightweight electronic transformer (ET), based on self-oscillating half-bridge high frequency inverter, are used to replace bulky and heavy conventional 50160 Hz step-down transformer. But their lamp current are rectangular like shape, leading to generate high electromagnetic noise and increase t...

The DC/AC inverters are used in grid-coupled Photovoltaic (PV) energy fabrication systems as the power meting out interface between the PV power source and the electric grid. Compared to the grid-coupled PV inverters that have galvanic separation (either on the DC, or on the AC side),the transformer-less PV inverters have the advantages of lower cost, higher efficiency, smaller size and lower w...

A new synchronous rectifier (SR) driving method is proposed using primary current sensing in this paper. Because the magnetizing current of transformer is included in primary winding of transformer, it can’t be used to generate the driving signals of SRs directly. A current compensating winding in current transformer is used to cancel out the magnetizing current and generate suitable driving si...

Toroidal transformers are used to measure the beam current in beam lines and accelerators. Placing such a transformer hi the feedback loop of an operational amplifier will increase the useful frequency range (active current transformer). A magnetic modulator can be added to extend the response to DC current, maintaining with a control loop the transformer core at a zero flux state. The magnetic...

This thesis describes how to provide standardized, current based, differential protection for any three-phase power transformer, including phase-shifting transformers with variable phase angle shift and transformers of all construction types and internal on-load tap-changer configurations. The use of standard transformer differential protection for such applications is considered impossible in ...

This study presents a novel technique based on Support Vector Machine (SVM) for the classification of transient phenomena in power transformer. The SVM is a powerful method for statistical classification of data. The input data to this SVM for training comprises fault current and magnetizing inrush current. SVM classifier produces significant accuracy for classification of transient phenomena i...