frequency response analysis (fra) is popular technique which has been used since the last decade as a diagnostic method for transformers. however, accurate interpretation of fra measurements is still challenging. recent studies reveal that apart from winding deformation, fra data can also be influenced by moisture variation in transformer paper insulation. hence, a specific transformer’s model ...

Bell Laboratories (Retired) and Consultant T his paper presents an easily understood analysis of the transmission line transformer (TLT). It also includes some history and the author's suggestion for the future of these devices. It is hoped that future device development and application will be encouraged. The TLT transmits the energy from input to output by a transmission line mode and not by ...

Partial discharges (PD) are recognized as the main cause of the inner insulation deterioration process in power transformers. Therefore, the optimum inner insulation design is one of the challenges a transformer designer is faced with. Transformer strength, especially during transient conditions, is a criterion for transformer insulation designers. This challenge has made designers initiate and...

Reliability of a power system is considerably influenced by its equipments. Power transformers are one of the most critical and expensive equipments of a power system and their proper functions are vital for the substations and utilities. Therefore, reliability model of power transformer is very important in the risk assessment of the engineering systems. This model shows the characteristics an...

Recently, the classical Hilbert transformer is generalized into the fractional Hilbert transformer which could be implemented optically. This modi"cation of the Hilbert transform adds an additional degree of freedom on the Hilbert transformer and improves the performance of the transform. In this paper, the design of FIR "lters fractional Hilbert transformer is proposed. The FIR "lters are desi...

An electronic current transformer with a B-dot sensor is proposed in this study. The B-dot sensor can realize the current measurement of the transmission line in a non-contact way in accordance with the principle of magnetic field coupling. The multiple electrodes series-opposing structure is applied together with differential input structures and active integrating circuits, which can allow th...

In order to study how acoustical factors influence annoyance responses to low frequency noise with tonal components, this research has selected 220 kV and 500 kV transformer noises as examples and an 11point numerical scale as an evaluation tool, in which the percentage of highly annoyed (%HA) and mean annoyance (MA) are chosen to represent annoyance caused by noises. Results show that a logist...

Transformer is one of the important electrical equipment that is used in power system. Monitoring transformer for the problem before they occur can prevent faults that are costly to repair and result in a loss of electricity. The main aim of the paper is to acquire real-time data of transformer remotely over the internet falling under the category of Internet of Things (IOT). For this real-time...

Practical aspects of design and application radio frequency (RF) transformers in an ultrasonic system excitation channel are analysed. Design steps are discussed for those willing to design their own transformer an for excitation channel. Investigation has been carried out on what generator parameters can be obtained if instead of a purely active output stage the impedance matching RF transform...

—Transformer terminal equivalents obtained via admittance measurements are suitable for simulating high-frequency transient interaction between the transformer and the network. This paper augments the terminal equivalent approach with a measurement-based voltage transfer function model which permits calculation of voltages at internal points in the regulating winding. The approach is demonstrat...