The traction transformer of the traction drive system of a high-speed train is one of the main equipments for energy conversion. The transformer loss will be increased by load harmonics and pantograph arcs at high speed. It is very important to predict losses for the improvement of traction transformer design. In this paper, a dynamic model of the pantograph-catenary system is established using...

In dual active bridge (DAB) converters, there can be transformer current ringing, especially when the turns ratio is high. It induced by high dv/dt generated fast switching as well low impedance of magnetic tank at high-frequency range. To quantify influence tank, its model thoroughly modeled considering all parasitic components. found that capacitors magnetics do not equally affect and thereby...

A current comparator technique, applied to several auxiliary instruments, enables accurate power measurements to be made for measuring losses in medium and large transformers. The instruments include high voltage active dividers with nominal outputs of 120 volts, a current transformer with nominal output of 1A and precision wattmeters. Two stage compensated current transformer technology is use...

When a transformer is energized the phenomenon of magnetizing inrush current occurs and causes a pseudo tripping signal to the differential relay which leads to the problem of mal operation or false tripping of the relay. In order to avoid this false tripping of the differential relay and for safe operation of the transformer the distinction of inrush current with internal fault current is very...

OF THESIS MATHEMATICAL MODEL FOR CURRENT TRANSFORMER BASED ON JILESATHERTON THEORY AND SATURATION DETECTION METHOD Current transformer saturation will cause the secondary current distortion. When saturation occurs, the secondary current will not be linearly proportional to the primary current, which may lead to maloperation of protection devices. This thesis researches and tests two detecting m...

one of the major problems that may occur in the differential protection systems of power transformers is mal-operation of the protection relays in sake of internal fault detection, because of similarity between this current and inrush current. this paper presents a novel approach for discriminating inrush current from internal fault in power transformers based on improved gravitational search a...