This study presents a novel technique based on Support Vector Machine (SVM) for the classification of transient phenomena in power transformer. The SVM is a powerful method for statistical classification of data. The input data to this SVM for training comprises fault current and magnetizing inrush current. SVM classifier produces significant accuracy for classification of transient phenomena i...

In this paper, a new algorithm based on processing differential current harmonics is proposed for digital differential protection of power transformers. This algorithm has been developed by considering different behaviors of second harmonic components of the differential currents under fault and inrush current conditions. In the new method, a criterion function is defined in terms of the time v...

Power transformer is a core equipment of power system, which undertakes the important functions of power transmission and transformation, and its safe and stable operation has great significance to the normal operation of the whole power system. Due to the complex structure of the transformer, the use of single information for condition-based maintenance (CBM) has certain limitations, with the ...

This paper proposed a new wavelet based method to identify inrush currents and to distinguish it from power system faults. The proposed algorithm extracts fault and inrush generated transient signals using DWT. Transient current signals at both sides of a transformer are firstly captured. The wavelet transform is a relatively new and powerful tool in the analysis of power transformer transient ...

The transformer plays so important equipment in power system that engineers take more measures on the insulating oil of transformer by diagnosis. The dissolved gas analysis (DGA) is an effective technique for detecting incipient faults in oil-immersed power transformers. So the paper investigates the DGA methods, while employ the ANSI/IEEE C57.104 standards and the Key Gas diagnosis rules as ba...

The knowledge of DC time constants in fault currents at system nodes is important to design the protection system and validate the calculation models for power system simulations. In this paper, we present methods to estimate Thévenin’s impedance and DC time constants in fault currents with application to disturbance records. Additionally, a comparison between both parameters is shown. We demon...

High power and high voltage gain DC-DC converters are key to high-voltage DC (HVDC) power transmission for offshore wind power. This paper presents an isolated ultra-high step-up DC-DC converter in matrix transformer configuration. A flyback-forward converter is adopted as the power cell and the secondary side matrix connection is introduced to increase the power level and to improve fault tole...

Transformer faults have many types and fault information is uncertain, in response to these problems, this paper presents evidence theory and neural network integrated fault diagnosis. In order to realize the reasonable assignment of reliability by Dempster combination rule after the information fusion between strong conflict evidence, the concept of a trust coefficient is introduced to correct...

Transformers are considered as significant equipments in electrical power systems, once failure ,the economic operation will be lost. To overcome this difficulty and to maintain economic operation of facilities, diverse diagnosis methods are developed to implement fault forecasting. According to intelligent complementary ideas, a fault diagnosis is proposed when there is a missing failure sympt...