Modeling and Simulation of Three-Phase Power Transformer (original) (raw)
Related papers
Energies, 2014
This paper proposes an algorithm for fault detection, faulted phase and winding identification of a three-winding power transformer based on the induced voltages in the electrical power system. The ratio of the induced voltages of the primary-secondary, primary-tertiary and secondary-tertiary windings is the same as the corresponding turns ratio during normal operating conditions, magnetic inrush, and over-excitation. It differs from the turns ratio during an internal fault. For a single phase and a three-phase power transformer with wye-connected windings, the induced voltages of each pair of windings are estimated. For a three-phase power transformer with delta-connected windings, the induced voltage differences are estimated to use the line currents, because the delta winding currents are practically unavailable. Six detectors are suggested for fault detection. An additional three detectors and a rule for faulted phase and winding identification are presented as well. The proposed algorithm can not only detect an internal fault, but also identify the faulted phase and winding of a three-winding power transformer. The various test results with Electromagnetic Transients Program (EMTP)-generated data show that the proposed algorithm successfully discriminates internal faults from normal operating
A Sensitive Method for Identifying winding turn to turn faults in Power Transformer
2011
This paper presents the development of a new approach for diagnosing the occurrence of turn to turn short-circuits in the windings of three-phase power transformers. The main problems of the current differential relay are short circuits of one or more turns of a transformer winding. Hence a new approach using' power differential' is developed to discriminate turn to turn faults by the sum of active power flowing into transformers from each terminal. The proposed scheme is tested using EMTP/ATP as well as an internal fault simulation program and gave reliable and accurate results.
Power transformers prove to be a vital element or tool in electrical power supply and transmission system. They are capital intensive units and need to be monitored for faults. Faults in transformers leading to their failure are unacceptable. Thus, there is a need to detect such faults at an initial level. This project is to detect the short circuit faults in any turn by theoretical and experimental methods, using frequency response analysis. Theoretical calculations are done by using the EMTP (electromagnetic transient program) software. With the help of EMTP voltage, current and frequency at each node can be seen. And further, by comparing these graphs with the faulty transformer, the fault can be identified at each node. Experimentally an electromagnetic model of the transformer is made by using enamel copper wire winding on a cylindrical hollow pipe. And by applying impulse voltage the respective current and voltage graph can be obtained, which can be further compared with the f...
2019
Turn to turn fault is one of the major internal failures in the power transformers that if it is not quickly detected, can be extended and led to a complete transformer breakdown. So, the diagnosis and location of the turn to turn fault of the power transformer, as one of the most important equipment in the power system, is the main objective of this paper. For this purpose, a detailed model of a three-phase transformer is presented by the finite element method (FEM) to investigate this fault in the different situations. Accordingly, the number of short-circuit turns as well as fault location, cause to generate the high forces between the short-circuit turns and the other healthy winding turns. Consequently, in this paper an appropriate method based on force analysis of winding turns for detecting, locating and determining fault severity is introduced. Keyword: Turn to turn fault, Recognition, location, imposed forces, FEM.
Transformers form a very important part of the power transmissions and distribution network; as they are responsible for the transfer of electrical energy from the power generation sites onto the transmission lines and finally to the distribution stage. Dry-type and oil-filled single-phase transformers, either alone or as a part of three-phase banks, are used extensively in the power distribution network, ultimately providing power to the domestic consumers. Any faults in the single-phase transformers leading to power outages or catastrophic power systems failures cause huge loss of capital, property and in some cases even human casualties. Gradual deterioration of the electrical winding insulation ultimately leads to inter-turn winding short circuit faults; which account for a significant proportion of all transformer failures. Incipient stages of inter-turn winding faults have negligible impact on the terminal voltages and currents of transformers; thus these faults often go undetected by the traditional differential relay based protection mechanisms.
Detecting the position of winding short circuit faults in transformer using high frequency analysis
In order to study the position of internal short-circuit in power transformers, the high frequency model for winding should be set up. In this paper a special methodology is used for establishing the high frequency model of transformer winding. This model topology is involved to reflect the internal electromagnetic behavior of such transformer. The proposed method is used in all part of transformer winding to completely represent the behavior of winding in different situation. The result predicts the position of short-circuit in each side of winding on different external condition. For better explanation several kind of curves are indicated which are drawn by MATLAB software.
2012
In this work, a new model of transformer winding is developed. The components in the model are determined by the geometric and electric data of the winding (detailed model) and using experimental data based on genetic algorithm. Under different degrees of axial displacement and radial deformation in the winding, the circuit parameters of the model will change and thus the equivalent circuit characteristics will be influenced. After acquiring the model parameters in the intact and faulted cases, transfer function coefficients are derived in model using nodal analysis. Subsequently, introducing a new index based on these coefficients, the type and extent of penetration of the fault in the winding can be specified. Results presented in this work demonstrate the potential of the proposed method.
Detection of arc faults in transformer windings by transient signal analysis
Research Square (Research Square), 2024
In power and distribution transformers, lightning strikes, switching operations, short-circuits and other reasons can cause deterioration of the winding insulation, resulting in arcing between the windings. The arcing event is very important in transformers and if it is detected late, it can cause a rigid short circuit and burn the transformer and even cause the transformer to explode due to heating and pressure. In this study, the effects of arcing between transformer windings on transformer end current and voltage waves are analysed and arcing is determined. In the study, a 15 MVA power transformer was modelled in three dimensions in the Ansys@Maxwell environment and the arc model created in Matlab@Simulink was adapted to the Ansys magnetic model and the arc in the transformer windings as a result of synchronous operation was analysed. The transient regime effects of arcing at 5 different points in the same high voltage winding of the transformer on the current and voltage waves at the input terminals of the transformer are analysed to obtain data that allow the fault to be detected in a short time without the use of sensors. The data obtained from the transformer input was transformed into the frequency domain using Fast Fourier Transform (FFT), and the high-frequency transient regime signals occurring in the transformer under arcing fault conditions were detected from these signals. Using the method proposed in the study, it is possible to detect the occurrence of arcing in the transformer.
Condition Monitoring and Diagnostics of Power Transformers
This paper addresses the subject of condition monitoring and diagnostics of power transformers. The main results of two reliability surveys, carried out under the auspices of CIGRE and IEEE in order to assemble objective data on the performance of transformers in service, are presented, providing useful information on the main causes of transformer failures, the most likely affected components and the related outages times. A survey of the most important methods, actually in use, for condition monitoring and diagnostics of power transformers is also given, which stresses the need for the development of new diagnostic methods, that can be applied without taking the transformers out of service, and that can also provide a fault severity criteria, in particular for determining transformers windings integrity. Preliminary results, concerning the on-going research activity on the development of a new approach for inter-turn winding fault diagnosis in three-phase transformers, are also reported in the paper.
International Journal of Power and Energy Research, 2017
A procedure and a corresponding computer program for determining the transient response of a transformer winding under faulty conditions are presented. The model is based on distributed-parameter analysis and is capable of taking the non-uniform distributions of the winding's inductances and capacitances into account. It will be demonstrated that snapshots of the instantaneous voltage and current distributions along the winding at any point in time, as well as the energization response to standard input stimuli can be efficiently utilized for monitoring the winding's conditions. An auxiliary function is suggested for simulating the different kinds, severities and locations of the internal faults. Results for both solidly-earthed and isolated transformer neutral points are given. It will be indicated that the source current includes useful information for assessing the winding's integrity and recognizing the type and location of eventually existing faults. It is believed that the presented approach can assist in providing helpful database for the condition monitoring of power transformers.