• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.311-313
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• 1996

In case of field weakening region, the dynamic behavior of the speed controller depends on the rotor flux level. In this region, the flux is decreased inversely proportional to the rotor speed. As the rotor flux is decreased, as the magnetizing inductance is increased. In this paper, the effect of this increased magnetizing inductance to the performance of vector control is illustrated. The stationary reference frame torque not including the magnetizing inductance is calculated by stationary stator flux, and the rotating reference frame torque including the magnetizing inductance is calculated by rotating rotor flux. If the magnetizing inductance value is constant, two torque values are same regardless of the flux-component current. However, if the magnetizing inductance is varied, those two values are different. The paper presents the new tuning scheme of the magnetizing inductance using the difference between the stationary and rotating torque. Computer simulation demonstrates the efficacy of the proposed scheme.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.2
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• pp.39-45
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• 1999

In case of field weakening region, torque is directly affected by flux. In this region, the flux reference is cIecreased inversely proportional to the rotor speed. As the flux is decreased, the magnetizing inductance is nonnally increased The increased magnetizing inductance limited voltage for controlling current In this paper, rreasuring q axis voltage in field weakening region, magnetizing inductance in flux calculating can be readjusted. Computer simulation and experiment results demostrate the efficacy of the prqx>sed rrethod. Proposed algorithm is expected to the application of the adjustable drive system in the spinning and weaving field. field.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.2136-2138
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• 1998

In this study, the speed sensorless vector control system with the magnetizing inductance compensation structure is presented. The estimations of the rotor speed and the magnetizing inductance using the terminal voltages and currents are performed with the reduced order Gopinath flux observer. The rotor speed is estimated by the torque producing current which is derived from the estimated value of the rotor flux and the measured stator currents. In order to compensate the variation of the magnetizing inductance under the saturated conditions, we also established the compensation scheme which is made with the instantaneous reactive power. The validity of the proposed method is verified by simulation results.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.2
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• pp.171-171
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• 1999

In case of field weakening region torque is directly affected by flux. In this region the flux reference is decreased inversely proportional to the rotor speed. As the flux is decreased the magnetizing inductance is normally increased. The increased magnetizing inductance limited voltage for controlling current. In this paper, measuring q axis voltage in field weakening region magnetizing inductance in flux calculating can be readjusted. Computer simulation and experiment results demonstrate the efficacy of the proposed method. Proposed algorithm is expected to the application of the adjustable drive system in the spinning and weaving field.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.5
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• pp.884-891
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• 2007

Comparing with the conventional transformer without the air gap, a contact-less transformer with the large air-gap (4.8cm) between the long primary winding and the secondary winding has the increased leakage inductance and the reduced magnetizing inductance. By the increased leakage inductance and the reduced magnetizing inductance on the primary of the contact-less transformer, a good deal of the primary current circulates through magnetizing inductance, which results in a massive loss and the high voltage gain characteristics for load variations in contact-less power supply (CPS). To consider these characteristics, in this paper, the efficiency characteristics of the contact-less power supply using a series resonant converter is presented, described and verified through theoretical analysis, computer simulation and experimental test of 2.5kW prototype.

• Journal of Electrical Engineering and Technology
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• v.1 no.4
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• pp.482-489
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• 2006

This paper presents the generalized dynamic modeling of self-excited induction generator (SEIG) using state-space approach. The proposed dynamic model consists of induction generator; self-excitation capacitance and load model are expressed in stationary d-q reference frame with the actual saturation curve of the machine. An artificial neural network model is implemented to estimate the machine magnetizing inductance based on the knowledge of magnetizing current. The dynamic performance of SEIG is investigated under no load, with the load, perturbation of load, short circuit at stator terminals, and variation of prime mover speed, variation of capacitance value by considering the effect of main and cross-flux saturation. During voltage buildup the variation in magnetizing inductance is taken into consideration. The performance of SEIG system under various conditions as mentioned above is simulated using MATLAB/SIMULINK and the simulation results demonstrates the feasibility of the proposed system.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.3
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• pp.207-214
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• 2016

Magnetic circuit is a physical modeling method that is useful in designing and analyzing power transformers, especially for a priori evaluation of leakage and magnetizing inductance before actual production. In this study, a novel modeling approach that uses PSIM magnetic elements adopting gyrator and permeance-capacitances is investigated. A formula to determine the permeance-capacitors in the core and leakage path are established, and a simulation jig is devised to link the physical model and the electrical terminal characteristics with an automated parameter determination process. The derived formula is verified by measurement results of the prototype transformer samples. Given its accuracy and simplicity, this approach is suitable for analyzing and designing LLC resonant transformers whose leakage and magnetizing inductance are very critical to circuit operation.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.919-922
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• 2006

Comparing with the conventional transformer without the air gap, a contact-less transformer with the large air-gap (4.8cm) between the long primary winding and the secondary winding has the increased leakage inductance and the reduced magnetizing inductance. By the increased leakage inductance and the reduced magnetizing inductance on the primary of the contact-less transformer, a good deal of the primary current circulates through magnetizing inductance, which results in a massive loss in contact-less power supply (CPS). In this paper, the efficiency characteristics of the contact-less power supply using a series resonant converter is analyzed and simulated. The results are verified on the simulation based on the theoretical analysis and the 1.8kW experimental prototype.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.50-52
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• 2006

This paper presents design consideration for LLC resonant converter utilizing the leakage inductance and magnetizing inductance of transformer as resonant components. The leakage inductance in the transformer secondary side is also considered in the gain equation. The design procedure is verified through experimental results.

• Journal of Electrical Engineering and Technology
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• v.1 no.3
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• pp.351-358
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• 2006

In this paper, the electrical characteristics of the contactless transformer is presented using the conventional coupled inductor theory. Compared with the conventional transformer, the contactless transformer has a large airgap, long primary wire and multi-secondary wire. As such, the contactless transformer has a large leakage inductance, small magnetizing inductance and poor coupling coefficient. Therefore, large magnetizing currents flow through the entire primary system due to small magnetizing inductance, resulting in low overall system efficiency. In high power applications, the contactless transformer is so bulky and heavy that it needs to be split by some light and small transformers. So, the contactless transformer needs several small transformer modules that are connected in series or parallel to transfer the primary power to the secondary one. This paper shows the analysis and measurement results of each contactless transformer module and comparison results between the series- and parallel-connection of the contactless transformer. The results are verified on the simulation based on the theoretical analysis and the 30kW experimental prototype.