• 전기학회논문지P
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• 제63권4호
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• pp.277-282
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• 2014

Hybrid transformer means the distribution transformer, one of multi-function transformer equipped with the enhancement function of harmonics and unbalance. In other words, since existing transformer are equipped simply with transformation function only, a separated electric facility should be additionally installed in order to reduce the mutual harmonics and unbalance. Meanwhile, since hybrid transformer can perform the reduction of harmonics and unbalance as well as transformation function simultaneously through zigzag winding, it doesn't need any additional electric facility. This study addressed the issue of developing and testing the performance of a generator that would reduce the harmonics supplied to the grid when grid-connected with the output of a photovoltaic inverter for photovoltaic generation system.

• 전기학회논문지P
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• 제63권4호
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• pp.333-338
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• 2014

This paper concerns the development of the transformer that can reduce harmonics supplied to the system if the output of photovoltaic inverter in the photovoltaic system is grid-connected, and suggests that problems of harmonics and power factor degradation in the grid-connected photovoltaic system can be improved. In this study, the burden of increasing the investment in new facilities and securing their installation space due to harmonics has been substantially eased through the development of a hybrid transformer possessing unbalanced function and harmonics reduction function using zig-zag coils, and most of all, it is expected that the development of such high efficiency hybrid transformer possessing functions of transformation and reducing harmonics can improve the power quality as well as prevent damages caused by harmonics, leading to suppress unnecessary loss of electric power and thereby contribute to energy savings.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.115-118
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• 2002

This paper presents the design method and performance characteristics of a chip-type quadrature hybrid using LTCC-MLC technology. The design method for a chip-type quadrature hybrid is based on lumped element equivalent circuit of quarter-wave transformer. The chip-type quadrature hybrid was miniaturized to a greater extent using multilayer structure and lumped element. The proposed design method can also reduce the undesirable parasitic effects of the chip-type quadrature hybrid. The proposed chip-type quadrature hybrid was designed and fabricated using the proposed design method and the equivalent circuit model of a quarter-wave transformer. Fabrication and measurement of designed chip-type quadrature hybrid show much smaller size than a conventional distributed quadrature hybrid and a good agreement with simulated results.

• 전기전자학회논문지
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• 제24권3호
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• pp.828-837
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• 2020

본 논문에서는 10W급 Tablet용 AC to DC Adapter의 소형화 및 슬림형에 적합한 평면 Flyback 변압기 최적화 설계에 대해서 나타낸다. 또한 본 논문에서는 수동권선의 기존 양산 Flyback 변압기에 비해 자동권선, Trans 크기 저감 및 누설 인덕턴스(L_k) 저감이 가능한 Hybrid형 사출 권선 변압기와 Drum형 사출 권선 변압기를 제안한다. 특히 본 논문에서 제안한 Drum형 사출 권선 변압기는 Hybrid형 사출 권선 변압기 2차측의 동판 사출 권선 접속 문제를 해결하기 위하여 변압기를 수평으로 눕힌 형태로 구성하였다. 본 논문에서 제안한 Hybrid형 사출 권선 변압기와 Drum형 사출 권선 변압기의 1차측과 2차측 권선은 각각 기존 권선과 동판 사출 권선을 사용하였다. 본 논문에서 제안한 Hybrid형 사출 권선 변압기와 Drum형 사출권선 변압기에 대해 Maxwell 2D 및 3D Tool을 이용하여 소형화 및 슬림형에 적합한 평면 Flyback 변압기 최적화 설계를 수행하였다.

• International Journal of Advanced Culture Technology
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• 제11권3호
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• pp.297-301
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• 2023

The study identified the various causes of odor problems, the discomfort they cause, and the importance of the public health and environmental issues associated with them. To solve the odor problem, you must identify the cause and perform an accurate analysis. Therefore, we proposed a CNN-Transformer hybrid model (CTHM) that combines CNN and Transformer and evaluated its performance. It was evaluated using a dataset consisting of 120,000 odor samples, and experimental results showed that CTHM achieved an accuracy of 93.000%, a precision of 92.553%, a recall of 94.167%, an F1 score of 92.880%, and an RMSE of 0.276. Our results showed that CTHM was suitable for odor analysis and had excellent prediction performance. Utilization of this model is expected to help address odor problems and alleviate public health and environmental concerns.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.607-612
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• 2002

This paper presents the first domestic model product of hybrid Insulation low-loss type pole transformer, with increased overload ability, increased life, reduced loss, focusing improved short-circuit characteristics. The capacity of this transformer is 100 KVZ, rates first voltage 13200 V and secondary voltage 230/115 type. The volume of model transformer that was produced in high temperature using hybrid insulation can be reduced to 10-20% in comparison with that of present transformer with the same capacity. In this paper, we did short-circuit test and tested general characteristics of model transformer. In addition, we suggested design application new concept and methods thorough this experiment.

• 조명전기설비학회논문지
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• 제21권7호
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• pp.84-93
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• 2007

주상변압기는 고객에게 직접 전력을 공급하는 설비로서 전력공급의 안정성확보를 위한 중요한 기자재 중 하나이다. 하지만 제조결함에 의한 3년 이내의 초기고장 또는 13년이 초과 사용한 후의 열화고장이 빈번히 발생하고 있어 변압기 품질분석을 통한 신뢰성이 개선된 주상변압기 개발이 필요하다. 본 논문에서는 열적, 기계적, 전기적으로 성능이 향상된 새로운 모델의 혼합절연 주상변압기를 개발하였다. 변압기의 기계적, 열적특성을 향상시키기 위한 혼합절연 방식에 대한 설계 및 제작방법을 제시하고 과부하시험을 시행하여 순간최대부하에 대응할 수 있도록 과부하내량 160[%] 까지 증가시킬 수 있음을 확인하였다. 또한 본 논문에서는 100[kVA] 1대를 시제품으로 제작하여 단락강도시험과 변압기 관련 절연시험을 시행하여 전자기계력의 분석과 단락강도설계 향상 방안에 대하여 설명하고 이와 관련하여 연구한 결과에 대해 논하였다.

• 전기학회논문지
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• 제62권7호
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• pp.931-936
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• 2013

In this paper, the temperature distribution of 400kVA hybrid transformer is predicted by using CFD analysis. The copper loss and iron loss which are heat source are calculated by using Joule heat and Bertotti's equation respectively. To improve the convergence of the numerical calculation and to reduce the computation time, the 1/4 model is used and the incompressible air model is used for external air. To verify analysis result, the temperature rise test and no-load test of the transformer are performed. The experiment result obtained by using thermo-graphic camera is similar to the numerical result of the CFD analysis.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.993-995
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• 2005

Recently, the efficiency of power transformer is improved as well as the size is becoming smaller. So, it is very important that temperature characteristics of the transformer should be estimated and predicted precisely. This paper deals with the temperature distribution of power transformer by simplified 2-D hybrid mesh model. The temperature distribution of model transformer was obtained by CFD algorithm considering natural convection. Heat sources are calculated first by magnetic field analysis based on F.E.M. and are usedas the input data for thermal field problem based on computational fluid dynamics(CFD) algorithm. The calculated temperature distribution of the simplified 2-D power transformer model shows good results in accuracy as well as in computing time.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.894-897
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• 1998

A conventional parallel hybrid active filter has an inherent problem of large current ratings of devices used in inverter. In general, this problem has been solved by adjusting turn ratio of a matching transformer. However, making the transformer with high turn ratio may be not available for high power system due to its requirement for high voltage insulation. In this paper, a new configuration is proposed for parallel hybrid active filter. In the proposed hybrid active filter, the active filter is connected to the passive filter inductor in parallel through a matching transformer for the aim of reducing the size of inverter. Through computer simulations, we have shown the outstanding performances of the proposed topology.