An improved transformer coupled gate driver scheme for high speed switching applications in power supply or motor drive is proposed in this paper. It improves the deficiencies caused by the conventional transformer coupled gate driver scheme, such as oscillation of the output PWM signal that will make MOSFET improper turn-on, when the duty cycle of input PWM signal reduces from large value to s...

Detection and removal of incipient faults in power transformer winding is essential because minor faults may develop and lead to major faults and finally irretrievable damages occur. This research article presenta a new, simple and incipient fault detection technique, which is based on symmetrical component approach. Using this protection technique, it is possible to detect minor turn-to-turn f...

Power transformer is one of the most important equipment in a power transmission and distribution system. This paper presents a technology to simulate differential relay in Matlab Simulink based environment for determining its behavior during various operating conditions. The results show that this simulation method can work properly and this will allow rapid modeling and testing of new algorit...

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...

In this work, a new approach applied to digital differential protection relay for a large power transformer is presented. First, the Fourier sine and cosine coefficients required for fundamental, second, third and fifth harmonic extraction have been determined using rectangular transfer technique. Then, these harmonics have been used in harmonics restrain and blocking techniques applied to diff...

This paper will propose a cascade of minimum description length criterion with entropy approach along with artificial neural network (ANN) as an optimal feature extraction and selection tool for a wavelet packet transform based transformer differential protection. The proposed protection method provides a reliable and computationally efficient tool for distinguishing between internal faults and...

Among the most noticeable root causes of improper performance in power transformers, internal short circuit faults can be noted and if not quickly be identified and addressed in the accepted time interval, irrecoverable damages such as interruption or even collapse of the network connected to the power transformer would happen. In this contribution, three-phase transformer behaviors under magne...

This paper presents an alternative approach using the differential logic associated to Artificial Neural Networks (ANNs) in order to distinguish between inrush currents and internal faults in the protection of power transformers. The Alternative Transients Program (ATP) has been chosen as the computational tool to simulate a power transformer under fault and energization situations. The Radius ...

The scope of this paper is to describe a real electrical installation of renewable energy using photovoltaic cells. The displayed power grid connected network was established in 2007 at area of Northern Greece. The photovoltaic park is composed of 6120 photovoltaic cells able to deliver a total power of 1.101.600 Wp. For the transformation of DC voltage to AC voltage have been used 25 stand alo...