Power transformers are key components for electrical energy transfer in a Power system. In order to protect the transformers from these faults different protective methods are adopted. Some of them are differential protection, over excitation Protection, etc. In this Paper Over Voltage protection is established for the protection of the transformer. Microcontroller is used for the Power Transfo...

This paper analyses the method to limit fault currents and pre fault bus voltage by the use of Thyristor Controlled phase Shifting transformer (TCPST). The mathematical model of power system equipped with TCPST was systematically derived. The magnitude of the series reactance plays a very important role to limit the short circuit current, as well as TCPST inject a series voltage which reduces t...

Measuring the current in the neutral-grounding resistor is needed for monitoring resistance-grounded three phase transformers. This current is limited to hundreds of amperes in case of a fault, and are almost negligible otherwise. The current transformer that senses the current must be rated for the fault conditions, thus it is difficult to obtain a precise measurement of the current when there...

This paper proposes an algorithm for CT saturation by behavior of distorted secondary current. The purpose of current transformer is to convert the primary current in the secondary circuit in a most accurate way. However, during fault conditions CT gets saturated. Some reasons due to current transformer (CT) can saturate like: attempting to mal operation of CT, heavy burden apply on the seconda...

Solid-state transformer (SST); Medium frequency transformer; AC/AC converter; Matrix converter Abstract This paper presents a novel topology of solid-state transformer (SST). In the design process, the AC/DC, DC/AC and AC/AC converters have been integrated to achieve higher efficiency. To obtain higher efficiency from other SST with DC-link topologies, the AC/DC and DC/AC converters have been i...

This paper presents the use of Artificial Neural Networks (ANN) as a pattern classifier for the combined differential protection of generator-transformer unit with an aim to build a backup protection system to improve the overall reliability of the system. The proposed neural network model is trained and tested with an efficient Resilient Back propagation (RPROP) algorithm and Genetic Algorithm...

In this paper, a new model has been presented to determine the number of spare transformers and their locations for distribution stations. The number of spare transformers must be so that they need minimum investment. Furthermore, they must be sufficient for replacing with transformers that have been damaged. For this reason, in this paper a new purpose function has been presented to maximize p...

This paper presents the development of a wavelet based algorithm, for distinguishing between magnetizing inrush currents and power system fault currents, which is quite adequate, reliable, fast and computationally efficient tool. The proposed technique consists of a preprocessing unit based on discrete wavelet transform (DWT) in combination with an artificial neural network (ANN) for detecting ...

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...

In this paper, various methods of providing restricted earth fault protection are discussed. The proper operation of high and low impedance Restricted Earth Fault (REF) protection for various applications has been discussed. The maloperation of a relay due to improper placement of CTs has been identified and a simple/unique solution has been proposed in this work with a case study. Moreover, it...