Computation of very fast transient overvoltages in transformer windings

Estimation of Very Fast Transient Voltage Distribution in air-cored Pulsed Transformer Windings Based on FDTD Method

To study the voltage distribution in transformer windings under VFTO, a model for transformer windings has been developed based on Multi-conductor Transmission-Lines (MTLs) theory and the computing equations of the model based on FiniteDifference Time-Domain method (FDTD) is deduced. The Vector Fitting method is adopted to treat the frequency-dependent parameter by expanding the time-domain for...

Transient Overvoltages in Power System

There are many reasons for over voltages in power system. The overvoltage causes number of effect in the power system. It may cause insulation failure of the equipments, malfunction of the equipments. Overvoltage can cause damage to components connected to the power supply and lead to insulation failure, damage to electronic components, heating, flashovers, etc. Over voltages occur in a system ...

Eddy Current Losses in Transformer Windings and Circuit Wiring

Skin Effect Figure 1 shows the magnetic field (flux lines) in and around a conductor carrying dc or low frequency current I. The field is radially symmetrical, as shown, only if the return current with its associated field is at a great distance. At low frequency, the energy in the magnetic field is trivial compared to the energy loss in the resistance of the wire. Hence the current Introductio...

On the Response of Interleaved Transformer Windings to Surge Voltages

New mitigation methods for transient overvoltages in gas insulated substations

During switching of disconnectors (DS) in GIS a varying number of pre-strikes and re-strikes occur. Due to the very short duration of the voltage collapse, traveling surges are generated in the busbar duct. These very fast transient overvoltages (VFTO) can become the limiting dielectric stress which defines the dimensions at UHV voltage levels. The decision shall be based on the maximum VFTO pe...