Results 11 to 20 of about 6,032 (308)

DC magnetisation of transformers [PDF]

IEE Proceedings - Electric Power Applications, 2006
A sufficiently high DC component in the current on the secondary side of a transformer causes distortion of the primary side current. Prediction of such distortion relies on the availability of magnetisation curves that extend deep enough into saturation.
Ahfock, A., Hewitt, A. J.
openaire   +2 more sources

Diagnosis of DC Bias in Power Transformers Using Vibration Feature Extraction and a Pattern Recognition Method

Energies, 2018
DC bias is a great threat to the safe operation of power transformers. This paper deals with a new vibration-based technique to diagnose DC bias in power transformers.
Xiaowen Wu, Ling Li, Nianguang Zhou, Ling Lu, Sheng Hu, Hao Cao, Zhiqiang He   +6 more
doaj   +2 more sources

Transformation of conventional transformers for enhanced DC mitigation in AC power networks with advanced grid support

e-Prime: Advances in Electrical Engineering, Electronics and Energy, 2023
The flow of quasi-DC or DC in AC networks may trigger half-cycle saturation of electrical grid transformers that could lead to their internal heating or grid collapse.
Moazzam Nazir, Klaehn Burkes, Johan H. Enslin   +2 more
doaj   +2 more sources

An asymmetrical quadruple active bridge series resonant DC–DC converter for modular solid‐state transformers

IET Power Electronics
The DC–DC conversion stage of a three‐stage solid‐state transformer is the most challenging due to the combination of high power, medium voltage, and medium frequency. This combination also causes most of the losses in the DC–DC stage.
Saeid Khani, Seyed Hossein Hosseini, Mehran Sabahi   +2 more
doaj   +2 more sources

Combination Optimization Configuration Method of Capacitance and Resistance Devices for Suppressing DC Bias in Transformers

Energies, 2019
The ground current of a high-voltage direct current (HVDC) transmission system can cause DC bias in transformers near the grounding electrode during monopole operations, which affects the alternating current (AC) power system operation. Owing to multiple
Donghui Wang, Chunming Liu
doaj   +2 more sources

A Novel DC Bias Suppression Method Considering the Cooperation of Multiple Devices

IEEE Access, 2021
The dc bias phenomenon caused by the excessive current of the neutral point will pose significant threats to the transformers. The conventional suppression method based on capacitive dc blocking device (BD) can prevent dc bias current from penetrating ...
Shumin Ma, Xiangning Lin, Zhengtian Li, Neng Jin, Zirui Rong, Peifu Zhang, Haibo Xu   +6 more
doaj   +1 more source

DC transformer for DC/DC connection in HVDC network [PDF]

2013 15th European Conference on Power Electronics and Applications (EPE), 2013
This paper presents the modeling and control of a multilevel DC/DC bidirectional converter suitable for medium voltage and power applications, with a special interest in wind-power applications. The proposed multilevel topology has a modular structure constituted by base DC/DC converter cells.
Carrizosa, Jimenez, Benchaib, Abdelkrim, Alou, Pedro, Damm, Gilney   +3 more
openaire   +2 more sources

A Power Flow Calculation Method for Multi-Voltage Level DC Power Grid Considering the Control Modes and DC/DC Converter

IEEE Access, 2023
Compared with traditional DC power flow analysis; multi-voltage level DC grid power flow analysis is more complex due to its diverse operation methods. This article proposes the power flow calculation method in multi-voltage level DC grid considering the
Shifeng Ye, Ruhai Huang, Jianxiang Xie, Jia Jun Ou   +3 more
doaj   +1 more source

A System-Level Suppression Method for DC Bias Based on Reverse Unbalanced Currents in the Same Transmission Section

IEEE Access, 2021
Conventional dc bias suppression strategies mainly rely on a single type of device, such as blocking capacitor or blocking resistance. However, these methods are passive palliatives and cannot restrain dc bias currents from the sources.
Shumin Ma, Xiangning Lin, Zhengtian Li, Neng Jin, Zirui Rong, Peifu Zhang, Haibo Xu   +6 more
doaj   +1 more source

Effect of external DC field on current transformers with amorphous and nanocrystalline cores [PDF]

, 2022
Nanocrystalline and amorphous stress-annealed and field annealed tapes are used for cores of DC-tolerant current transformers. We analyze the influence of external DC field of arbitrary direction on the performance of these transformers.
Ripka P., Mlejnek P., Mirzaei M.
core   +1 more source