A novel annular parallel-strip transmission line was devised to construct high-voltage high-speed pulse isolation transformers. The transmission lines can easily realize stable high-voltage operation and good impedance matching between primary and secondary circuits. The time constant for the step response of the transformer was calculated by introducing a simple low-frequency equivalent circui...

The traditional grid-connected PV inverter includes either a line frequency or a high frequency transformer between the inverter and grid. The transformer provides galvanic isolation between the grid and the PV panels. In order to increase the efficiency, to reduce the size and cost, the effective solution is to remove the isolation transformer. It leads to appearance of common mode (CM) ground...

Detecting and removing minor faults in power transformer winding is essential because minor faults may develop and lead to major faults and finally irretrievable damages occur. In this paper in order to detect the position of short-circuit in the winding, frequency response of the input impedance of a power transformer is analyzed. Common short-circuits are categorized and the results are compa...

The MV/LV transformer without a tank in the underground substation can produce remarkable interference with the computer Cathode-Ray Tube (CRT) displayers above the ground, because of the generated power frequency magnetic field. To resolve such problem, a tank with high conductivity or/and high permeability is needed to enclose the transformer. To evaluate the shielding effectiveness, the fini...

This paper describes the technical challenges tied to modeling and design optimization of the medium frequency transformer (MFT) for power electronic applications, namely emerging solid state transformers (SSTs). A detailed analysis and modeling of the phenomena governing the MFT electrical behavior as well as limiting the operation and design range is performed. A synthesis of all these models...

Power transformers prove to be a vital element or tool in electrical power supply and transmission system. They are capital intensive units and need to be monitored for faults. Faults in transformers leading to their failure are repugnant. Thus, there is a need to detect such faults at an initial level. This paper aims to detect, diagnose the nature and cause of mechanical faults, their identit...

This paper presents implementations of a nonisolated, high voltage gain DC-DC converter. High voltage gain is achieved due to inclusion of resonance and transformer in the circuit. The performance of this converter is compared with two similar topologies namely coupled inductor-switched capacitor step-up converter and coupled inductor step-up converter. The proposed prototype is designed using ...

Magnetic core saturation of transformers and rotating machines generate harmonics. Harmonics are integer multiples of the fundamental frequency. Harmonics is caused by nonlinear devices in the power system. Due to the non-linear loads, power frequency harmonics exist mainly in distribution systems. The current harmonics cause voltage harmonics, hence resulting in nonsinusoidal supply voltage in...

In this paper, a new method for estimation of transient parameters of transformer high voltage winding using the artificial neural networks (ANN) is proposed. An ANN with different structures is trained for parameters estimation of transformer winding Detailed Model that data is generated by analysis of frequency response. It is shown that feed-forward back propagation network with Levenberg-Ma...

(Received: October 30, 2011; Accepted: December 8, 2011) Abstract: This paper presents a novel technique for transformer differential protection to prevent incorrect operation due to inrush current. The proposed method in this paper is based on time-frequency transform known as the Wavelet transform. The discrete Wavelet transform is used for analysis the differential current signals in time an...