< p>The restricted earth fault (REF) protection is provided for electrical power transformer in order to sense internal faults, mainly because it more sensitive than the main differential protection. However, The REF relay may maloperate when current (CT) saturation happens following a severe external fault. In this paper, new simple algorithm proposed scheme which realized by considering four ...

Abstract In power systems, busbars connect important components such as generators, transmission lines, and loads. A typical fault occurrence on the busbar may result in isolation of faulty sections from other normally operating parts system resulting differential protection operation. Although main busbars' scheme is protection, its operation significantly affected by magnetic saturation curre...

A new approach for protection of power transformer is presented using a time-frequency transform known as Wavelet transform. Different operating conditions such as inrush, Normal, load, External fault and internal fault current are sampled and processed to obtain wavelet coefficients. Different Operating conditions provide variation in wavelet coefficients. Features like energy and Standard dev...

A platform implemented with Digital Signal Controllers (DSCs) developed for real time studies of the dynamic behavior of the air-gapped current transformers (CTs) used in power grid protection and measurement systems is presented. The implemented algorithms simulate the fault current in an electric power system as well as the transient response of the current transformer. It is also presented a...

rotection schemes employing the differential relaying principle exhibit certain limitations in applications with power transformers. This is because the detection of a differential current does not clearly distinquish between internal faults and other possible conditions. Among the phenomena most likely to upset the current balance and cause the relay to malfunction are inrush magnetizing curre...

Second harmonic restraint is still commonly used to discriminate fault current and transformer inrush conditions. Such approach, however, has some disadvantages and limitations. Therefore various other criteria signals for power transformer inrush discrimination have been analysed. The paper presents a new multi-criteria stabilization algorithm that employs fuzzy reasoning technique for better ...

1.0 Abstract In recent times, there is a big explosion of embedded devices like PDAs and digital cameras in the consumer market arena. In order to incorporate these new devices into the computer systems a large number of device drivers have been written by different vendors. One way to define device drivers is to view them as an extension to the operating system kernel. Today the preferred way ...

In many text books and papers such as [1]-[5], it is possible to find descriptions about shunt fault calculations and about the influence of the three-phase transformer connection Dyn on the fault currents distribution through distribution transformers. In [6] is described a method for digitally simulating a three-phase power system which is subjected to a fault at one location with blown fuse ...