• 전력전자학회논문지
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• 제19권2호
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• pp.164-172
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• 2014

This paper presents an analysis of a leakage inductance for a toroidal type flyback transformer. The equation to calculate the leakage inductance is derived using the MMF diagram of the transformer. The analysis for the different types of the cores and winding structures is also provided using the FEM simulation. The winding structures minimizing the leakage inductance are finally discussed from the simulation and experimental results.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 전력전자학술대회 논문집
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• pp.180-181
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• 2013

This paper represents an analysis of a leakage inductance for a toroidal type flyback transformer. The equation to calculate the leakage inductance is derived using its MMF diagram. The analysis for the different types of the cores and winding structures is also provided using the Maxwell 3D simulation. The winding structures minimizing the leakage inductance are finally discussed, from the simulation results.

• 한국산학기술학회논문지
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• 제11권2호
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• pp.497-507
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• 2010

본 논문은 상이한 누설인덕턴스를 가진 두 개의 변압기를 이용하여 전류불균형을 개선한 하프브리지 LLC 공진형 컨버터를 제안한다. 제안된 컨버터는 변압기의 누설인덕턴스와 자화인덕턴스 및 공진커패시턴스를 이용하여 공진하고, 넓은 부하영역을 가지며, 경부하에서도 영전압스위칭 조건을 만족한다. 직/병렬로 연결된 두 개의 변압기는 동작모드에 따라 변압기 또는 공진인덕턴스로써 교대로 동작하고, 변압기 2차측에는 누설인덕턴스를 이용하므로 별도의 출력 필터인덕턴스가 필요하지 않다. 또한 제안된 컨버터는 두 변압기의 상이한 누설인덕턴스와 하프브리지 스위치의 비대칭 펄스폭변조를 이용하여 2차측 정류다이오드의 전류불균형 문제를 개선한다. 본 논문에서는 제안된 컨버터의 동작원리를 모드별로 설명하고 프로토타입 컨버터의 설계 예를 제시한다. 제안된 컨버터의 우수한 성능을 입증하기 위하여 설계된 프로토타입의 회로파라미터로써 프로토타입 컨버터를 제작하고 실험하였다. 제안된 컨버터의 우수한 성능을 실험결과를 통하여 보인다.

• 전력전자학회논문지
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• 제20권3호
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• pp.255-261
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• 2015

An analysis of the interleaving effect for the secondary winding distribution of a toroidal transformer is presented in this paper. The equations to calculate the leakage inductance of the toroidal transformer are derived using MMF diagrams for the different secondary winding distributions. The simulation and experimental results are provided to show the validity of the theoretical calculation.

• Journal of Electrical Engineering and Technology
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• 제11권1호
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• pp.135-142
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• 2016

Generally, closed slots are adopted to reduce the water friction loss in both the stator and the rotor of water filling submersible motor due to the special environment of operation. One of the obvious differences between the traditional induction motors and water filling submersible motors is that the submersible motors only need relatively smaller starting torque. This paper aims to analyze the slot leakage reactance of water filling submersible motor during starting transient operation. An improved analytical method which considered the magnetic saturation of the slot bridge and the skin effect of rotor bars is proposed. The slot permeance factor which has a direct impact on the slot leakage reactance is calculated. Then finite element models with different stator slot types are constructed and search coils are introduced to measure the slot flux linkage. Moreover, the starting performances of the models with two typical stator slots are compared and the flux leakage characteristics are obtained. Finally, the results obtained by finite element method are very close to the results obtained by analytical method.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 전력전자학술대회 논문집
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• pp.231-232
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• 2016

This paper investigates the design of multi-winding coupled inductor for minimum inductor current ripple. Based on the general circuit model of coupled inductor together with the operating principles of dc-dc converter, the relationship between the ripple size of inductor current and the coupling factor is derived under the different duty ratio. The optimal coupling factor of n-phase multi-winding coupled inductor which corresponds to a minimum inductor ripple current becomes -(1/n-1), i.e. a complete inverse coupling without leakage inductance, as the duty ratio of steady-state operating point approaches 1/n, 2/n, ${\cdots}$ or (n-1)/n. In an opposite manner, the optimal coupling factor value of zero, i.e. zero mutual inductance, is required when the duty ratio of steady-state operating point approaches either zero or one. Therefore, coupled inductors having optimal coupling factor can minimize the ripple current of inductor and inductor size.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2017년도 전력전자학술대회
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• pp.88-89
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• 2017

This paper investigates the design of multi-winding coupled inductor for minimum inductor current ripple in rapid traction battery charger systems. Based on the general circuit model of multi-winding coupled inductor together with the operating principles of dc-dc converter, the relationship between the ripple size of inductor current and the coupling factor is derived under the different duty ratio. The optimal coupling factor which corresponds to a minimum inductor ripple current becomes -(1/n-1), i.e. a complete inverse coupling without leakage inductance, as the steady-state duty ratio operating point approaches 1/n, 2/n, … or (n1)/n. In an opposite manner, the optimal coupling factor value of zero, i.e. zero mutual inductance, is required when the steady-state duty ratio operating point approaches either zero or one.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2015년도 전력전자학술대회 논문집
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• pp.195-196
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• 2015

This paper investigates the design of coupled inductor for minimum inductor current ripple in rapid traction battery charger systems. Based on the general circuit model of coupled inductor together with the operating principles of dc-dc converter, the relationship between the ripple size of inductor current and the coupling factor is derived under the different duty ratio. The optimal coupling factor which corresponds to a minimum inductor ripple current becomes -0.5, i.e. a complete inverse coupling without leakage inductance, as the steady-state duty ratio operating point approaches 1/3 or 2/3. In an opposite manner, the optimal coupling factor value of zero, i.e. zero mutual inductance, is required when the steady-state duty ratio operating point approaches either zero or one. Coupled inductors having optimal coupling factor can minimize the ripple current of inductor and battery current resulting in a reliable and efficient operation of battery chargers.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.21-23
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• 2007

It is well known that the characteristics of the induction machine depend on a great degree on the leakage reactance. And the leakage reactance is different according to a level of slant. So in this paper, we calculated the inductance per coil side. And the torque and speed characteristics are analyzed using a method base on the two-dimensional (2-D) finite element method (FEM) and on the circuits theory to model the rotor bar in a induction machine. The variable values of bar angle of slant are considered.

• 전력전자학회논문지
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• 제25권1호
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• pp.13-20
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• 2020

Accurate parameters based on equivalent circuit are required for high-performance field-oriented control in a three-phase induction motor. In a normal case, stator resistance can be accurately measured using a measuring equipment. Except for stator resistance, all machine parameters on the equivalent circuit should be estimated with particular algorithms. In the viewpoint of traditional regions, the parameters of an induction motor can be identified through the no-load and standstill test. This study proposes an identification method that uses the d-axis model of the induction motor in a stationary frame with the predefined information on stator resistance. Mutual inductance is estimated on the rotational dq coordination similar to that in the traditional no-load experiment test. The leakage inductance and rotor resistance can be estimated simply by applying different voltages and frequencies in the d-axis model of the induction motor. The proposed method is verified through simulation and experimental results.