Transformer magnetizing inrush currents

Specht, T. R.

doi:10.1109/ee.1951.6437380

Cited by 9 publications

(4 citation statements)

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“…Boşta çalışma akımı cer transformatörü enerjilendirildikten sonra geçici durumun bitmesi halinde çekilen akım formudur. Bu akım formu nüve özelliklerine, uyarma gerilimine ve modelin geometrik yapısına bağlıdır [36]. Uygun analiz ayarları ile birlikte Şekil-6 üzerinde gösterilen boşta çalışma akımı bulunabilmektedir.…”

Section: Boşta çAlışma Akımıunclassified

Cer Transformatörlerinde Elektriksel Parametrelerin Sonlu Elemanlar Yöntemi ile Analizi

Çürükova¹,

Demirol²,

Sönmez³

et al. 2022

Demiryolu Mühendisliği

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Traction transformers feed the motor drivers used in electric locomotives in railway systems. Traction transformers are placed in a limited area above or below the locomotives. Due to the power needs of the equipment used in train systems, there are many winding structures at different voltage levels in traction transformers. Therefore, the design parameters of traction transformers should be specifically evaluated for providing a high level of sustainability, efficiency, and operational safety in railway systems. It is crucial to carry out detailed analyses during the design phase and evaluate them according to standards. Accurate calculation of critical electrical parameters such as short circuit impedance, inrush currents, tank losses and core losses in traction transformers is not always possible or very laborious with theoretical methods. In this case, the finite element analysis method has many advantages. With finite element analysis, calculations can be made with high accuracy and in a short time. This study calculated the electrical parameters of a sample traction transformer with Ansys Electronics Suite finite element analysis software. Summary information about the calculated parameters is given, and the analysis steps are explained. In this context, the necessity of the finite element method for the electrical analysis of traction transformers, which is one of the most critical components in railway systems, has been expressed.

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Section: Boşta çAlışma Akımıunclassified

Cer Transformatörlerinde Elektriksel Parametrelerin Sonlu Elemanlar Yöntemi ile Analizi

Çürükova¹,

Demirol²,

Sönmez³

et al. 2022

Demiryolu Mühendisliği

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“…This is a common practice when performing sensitivity analysis specially if the transformer has not been built or purchased. Such "reference inrush current" may be due to field data from similar transformers, worst-case scenario calculations such as [31], [32], or even empirical values 2 . In such cases, it is possible to run multiple EMT simulations and experimentally adjust L air until matching inrush current is simulated.…”

Section: E Parameter Determinationmentioning

confidence: 99%

“…Results are summarized in Table 4 in terms of the peak values. For comparison, the table also includes simulation results from the unified magnetic equivalent circuit (UMEC) model [12], [13] as well as the values provided by the manufacturer based on analytical calculations [31]. However, it should be noted that there are differences in the modeling and calculation techniques presented in Table 4.…”

Section: ) Worst-case Remanencementioning

confidence: 99%

Application of Duality-Based Equivalent Circuits for Modeling Multilimb Transformers Using Alternative Input Parameters

Shafieipour

Ziomek²,

Jayasinghe

et al. 2020

IEEE Access

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The principle of duality is applied for electromagnetic transient (EMT) modeling of industry scale (i.e. 50, 390 MVA) multilimb transformers. While saturation, hysteresis, deep-saturation, and remanent flux are accounted for, the need for transformer internal design information such as core dimension or material is eliminated. This is achieved by formulating the equivalent circuits with an alternative set of parameters that are either provided by the manufacturer or can be determined using conventional techniques. Open-circuit tests confirm that the models produce accurate excitation currents at different saturation levels when compared with measurement results. Furthermore, the models facilitate correct short-circuit condition with support for arbitrary number of windings. Upon validating the models, inrush current is simulated and the worst-case scenario is determined due to potential remanent flux values. The findings agree with an established EMT simulation model as well as manufacturer analytical approximations. Simulated hysteresis loops are also investigated.INDEX TERMS Principle of duality, 3-limb and 5-limb transformer models, miltilimb multiwinding transformers, inrush current, remanent flux, hysteresis loop, electromagnetic transient.

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“…A large difference between the actual grid and sub-inverter output voltages owing to the time delay can result in an offset in the transformer flux and generate an inrush current owing to the saturation phenomenon. The inrush current could be several times higher than the rated current of the inverter [34,35], and overcurrent protection may get activated when the sub-inverter is operated. Figure 4 shows the experimental waveforms of the inrush current as a function of the load voltage generated during inverter start-up, when fast system recovery control is used under a 10 kW load condition.…”

Section: System Analysismentioning

confidence: 99%

LCpL Filter Design and Control for Stability Improvement in a Stand-Alone Microgrid with Sub Inverter Structure

2019

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The inverter of an energy storage system, which plays an important role in maintaining the voltage of a stand-alone microgrid, can shut down in response to external or internal abnormal conditions. Such a protective measure can cause the microgrid to blackout. A redundant inverter can be configured to respond upon failure of the main inverter to ensure higher stability of the stand-alone microgrid. However, the microgrid may experience several to tens of blackout cycles when the main inverter fails owing to a time delay in the operation of the sub inverter. To overcome this limitation, we propose an LCpL filter for suppressing any sudden changes in the microgrid during the transition period between the main and sub inverters. In addition, this study also describes a control method for the sub inverter to prevent system blackouts. A 100 kW microgrid system consisting of two 100 kW inverters with LCpL filters and loads was used to demonstrate the efficacy/utility of the proposed method.

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Transformer magnetizing inrush currents

Cited by 9 publications

References 0 publications

Cer Transformatörlerinde Elektriksel Parametrelerin Sonlu Elemanlar Yöntemi ile Analizi

Cer Transformatörlerinde Elektriksel Parametrelerin Sonlu Elemanlar Yöntemi ile Analizi

Application of Duality-Based Equivalent Circuits for Modeling Multilimb Transformers Using Alternative Input Parameters

LCpL Filter Design and Control for Stability Improvement in a Stand-Alone Microgrid with Sub Inverter Structure

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