A Calculation Method to Adjust the Short-Circuit Impedance of a Transformer

Ye, Zhijun; Wang, Yu; Gou, Julong; Tan, Kaijia; Zeng, Wenhui; An, Bonan; Li, Yong

doi:10.1109/access.2020.3042983

Cited by 14 publications

(7 citation statements)

References 8 publications

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“…During the operation stage, the coordination of protection relays R1-R2-R3 (corresponding to CB1-CB2-CB3) is analyzed at a low voltage or 380V section. The coordination is arranged with a minimum grading margin of 0.3 seconds [6], [29]. Each overcurrent protection relay implements a combination of IDMT standard inverse and definite time.…”

Section: Overcurrent Protection and The Coordinationmentioning

confidence: 99%

Protection coordination analysis applied at biogas power generation plant

Siregar

Tjumar

Mubarakah

et al. 2023

IJEECS

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Biogas from liquid waste from palm oil processing, palm oil mill effluent (POME), can be utilized in biogas power plants as a source of renewable energy (PLTBg). The PLTBg electrical system is equipped with a coordinated protection system. Then, the protection system must also maintain the continuity of electrical service in parts that are not affected by disturbances. Coordination of the protection system is essential. In this research, the electrical transient analysis program (ETAP) carries out the short circuit current analysis, and the coordination of overcurrent protection is constructed from its inverse-definite minimum time characteristics. The analyzed data contributed to selecting the right protection devices. A combination of overcurrent protection, directional protection, and frequency protection change rate supported a reliable electrical power system for a biogas power generation plant as distributed generation. The result shows that modern microprocessor-based protection relays support several protection features in one device and can be integrated into a supervisory control and data acquisition (SCADA)-controlled protection system to enhance their capabilities.

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Section: Overcurrent Protection and The Coordinationmentioning

confidence: 99%

Protection coordination analysis applied at biogas power generation plant

Siregar

Tjumar

Mubarakah

et al. 2023

IJEECS

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“…For instance, frequency response analysis (FRA) can determine the condition of the winding by measuring the impedance or admittance of the winding [ 4 , 5 , 6 ]. Short-circuit impedance (SCI) is available to evaluate the transformer operating condition [ 7 ]. Similarly, the winding resistance measurement is used to evaluate the contact condition of the winding conductors and the tap changer, and the winding ratio test can determine if there are shorted turns or open winding circuits.…”

Section: Introductionmentioning

confidence: 99%

Convolutional Neural Network-Based Transformer Fault Diagnosis Using Vibration Signals

Chen

Yang³

et al. 2023

Sensors

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Fast and accurate fault diagnosis is crucial to transformer safety and cost-effectiveness. Recently, vibration analysis for transformer fault diagnosis is attracting increasing attention due to its ease of implementation and low cost, while the complex operating environment and loads of transformers also pose challenges. This study proposed a novel deep-learning-enabled method for fault diagnosis of dry-type transformers using vibration signals. An experimental setup is designed to simulate different faults and collect the corresponding vibration signals. To find out the fault information hidden in the vibration signals, the continuous wavelet transform (CWT) is applied for feature extraction, which can convert vibration signals to red-green-blue (RGB) images with the time–frequency relationship. Then, an improved convolutional neural network (CNN) model is proposed to complete the image recognition task of transformer fault diagnosis. Finally, the proposed CNN model is trained and tested with the collected data, and its optimal structure and hyperparameters are determined. The results show that the proposed intelligent diagnosis method achieves an overall accuracy of 99.95%, which is superior to other compared machine learning methods.

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“…Fifth, we have completed the production of a non-metallic cryostat, which reduces the weight, improves the superconducting transformer's insulation performance, and eliminates the impact of eddy current loss. Finally, according to conventional traction transformer (CTT) design and test methods, we have completed the short-circuit impedance analysis and testing of the 6.6 MVA HTSTT [28].…”

Section: Introductionmentioning

confidence: 99%

Design, development, and testing of a 6.6 MVA HTS traction transformer for high-speed train applications

Zhao

Fang

Jiang

et al. 2023

Supercond. Sci. Technol.

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High-temperature superconducting traction transformers (HTSTT) have the merits of small size and lightweight in comparison with their conventional counterparts. This article reports the development progress of a 6.6 MVA HTSTT operating at 65 K, including the design, testing, and system cooling. The introduction of flux diverters and an optimized winding design realized a short-circuit impedance higher than 43% and AC loss less than 3 kW. The insulation structure was designed to pass insulation tests specified in standard in China GB/T 25120-2010. An open cooling system with reduced pressure was developed, which realized the efficiency of the 6.6 MVA HTSTT above 99%. Before assembling the prototype transformer, we conducted tests for critical current and dielectric performance of the HTS double pancake coils (DPC) used in high-voltage (HV) and low- voltage (LV) windings to verify the current-carrying and insulation performances of each DPC. Finally, we measured the critical current and no-load loss of the HTSTT prototype at 77 K. Test results showed that the mass of the transformer is 33% less than conventional transformers. At 77 K, the critical current of the LV winding and HV winding is higher than 700 A and 50 A, respectively. Moreover, the HTSTT on a no-load test reached the test voltage of 25,000 V and loss of 6 kW. In the next step, we will continue to conduct experimental research, and verify the feasibility of the HTSTT on the train, and develop a circulating cooling system, all meeting the commercial requirements of the HTSTT. 

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A Calculation Method to Adjust the Short-Circuit Impedance of a Transformer

Cited by 14 publications

References 8 publications

Protection coordination analysis applied at biogas power generation plant

Protection coordination analysis applied at biogas power generation plant

Convolutional Neural Network-Based Transformer Fault Diagnosis Using Vibration Signals

Design, development, and testing of a 6.6 MVA HTS traction transformer for high-speed train applications

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