• Journal of Industrial Technology
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• v.25 no.B
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• pp.195-202
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• 2005

The rectifier characteristics and the quality of the input current worsens with the increase of unbalances or harmonics of the supply voltages. Rectifier input current harmonics interfere with proper power system operation, reduce rectifier power factor, and limit the power available from a given source. It is of importance to select appropriately the rectifier's output filter inductance to determine the rectifier input current waveform, the input current harmonics, and the power factor. This paper presents a quantitative analysis of single and three phase rectifier input current harmonics, total harmonic distortion, and power factor as a function of the output filter inductance under balanced and unbalanced conditions. Also, its performance under the supply voltage including harmonics be investigated. These results provide a reference for selecting reasonable rectifier's output filter inductance for given harmonics or power factor criterion.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.6
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• pp.484-489
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• 2020

This study proposes a new soft-switching three-level flying capacitor converter with low filter inductance. The proposed converter can achieve zero voltage switching (ZVS) turn-on of all switches by using auxiliary components La and Ca. It can also reduce filter inductance because the applied voltage of the filter inductor is decreased by using the flying capacitor. Furthermore, filter inductance can be reduced because the operating frequency of the filter inductor is doubled by the phase shifting between switches S3 and S4. The operation principle, design of passive components for ZVS turn-on, interleaving effects, and comparison of different topologies are presented. The experimental waveforms of a 1 kW two-phase interleaved converter prototype are provided to verify the validity of the proposed converter.

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.3
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• pp.282-290
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• 2001

The accurate identification of the motor parameters is crucially important to achieve high dynamic performance of induction motors. In this paper, th motor parameters such as stator(rotor) resistance, stator(rotor) leakage inductance, mutual inductance, and rotor inertia are measured in off-line. Stator(rotor) resistance and stator(rotor) leakage inductance are measured based on the stationary coordinate equations of induction motors. On the other hand, mutual inductance are measured under the scalar control. Finally, the inverse rotor time constant is identified in on-line using an extended kalman filter algorithm. To demonstrate the practical significance of the results, Some experimental results are presented.

• Journal of the Korean Institute of Telematics and Electronics
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• v.11 no.4
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• pp.19-24
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• 1974

An ungrounded inductance, necessary for construction of general type networks, is synthesized using two operational amplifiers and several passive elements. Through indefinite admittance matrix procedure. it is proved that the synthesized network is equivalent to an ungrounded pure inductance with a positive and a negative resistance in the parallel arms. A practical low-pass filter is made according to this synthesis method, and the resultant characteristic has been verified by means of IBM's simulation program ECAP (Electronic Circuit Analysis Program).

• Journal of Power Electronics
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• v.11 no.6
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• pp.793-800
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• 2011

This paper investigates the operational modes of buck dc-dc converters and their energy transmission methods. The operational modes of such converters are classified in two types, discontinuous conduction mode (DCM) and continuous conduction mode (CCM). In this paper, the critical inductance relation of DCM and CCM is determined. The equations of the output voltage ripple (OVR) for each mode are obtained for a specific input voltage and load resistance range. The maximum output voltage ripple (MOVR) is also obtained for each mode. The filter size is decreased and the minimum required inductance value is calculated to guarantee the minimization of the MOVR. The experimental and simulation results in PSCAD/EMTDC prove the correctness of the presented theoretical concepts.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.4
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• pp.625-640
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• 2023

This paper propose a circuit that can measure the inductance of an inductive sensor used in IOT applications. The circuit was constructed using the characteristics of an RL low-pass filter circuit, comparator, current control switch, and capacitor, and the inductance value within the range 1[nH] < L ≤ 1[H] can be derived through the duration time during the output voltage of the RL low-pass filter circuit is greater than the reference voltage.

• Journal of Power Electronics
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• v.9 no.4
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• pp.623-630
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• 2009

This paper proposes a filter design guideline for grid-connected single-phase inverters. By analyzing the instantaneous voltage applied to the filter inductor, the switching ripple current through the filter inductor can be precisely calculated. Therefore, filter inductance can be designed accurately, which guaranties that the switching ripple current will be under the target value. The proposed filter design method is verified by experiment.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.102-105
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• 2003

The leakage inductance of the High frequency Transformer(HFT) in the flyback topology can be used an inductor of the Low Pass Filter(LPF) to reduce ripple and ripple noise in the output voltage. But, the values of leakage inductance and magnetizing inductance in the HFT are within $\pm20[{\%}]$). And the operating temperature of the HFT increased by the leakage inductance. Therefore, the leakage inductance of the HFT in the flyback topology has minimum and the LPF has non-polarity ceramic capacitor in the output stage. In this paper, the LPF in the flyback topoBogy takes PCB capacitor using double layer of PCB without non-polarity ceramic capacitor. Its experimental results show the reduced ripple noise and the reduced ripple in the output stage.

• Journal of Electrical Engineering and Technology
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• v.11 no.1
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• pp.100-108
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• 2016

This paper presents a simple high efficiency full-bridge DC-DC converter using a series resonant capacitor. The proposed converter achieves the zero voltage switching of the primary switches under a wide range of load conditions and reduces the high circulating current in the freewheeling mode using the leakage resonant inductance and the series resonant capacitor. Thus, the proposed converter overcomes the drawbacks of the conventional full-bridge DC-DC converter and improves its overall system efficiency. Its structure is simplified by using the leakage inductance of the transformer as the resonant inductance and omitting the DC output filter inductance. Also it can operate over a wide range of input voltages. In this paper, the operational principle, analysis and design example are described in detail. Finally, the experimental results from a 650W (24V/27A) prototype are demonstrated to confirm the operation, validity and features of the proposed converter.

• Journal of Electrical Engineering and Technology
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• v.9 no.2
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• pp.600-608
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• 2014

This paper presents estimation of d-axis and q-axis inductance of an interior permanent magnet synchronous motor (IPMSM) by using an extended Kalman filter (EKF). The EKF is widely used for control applications including the motor sensorless control and parameter estimation. The motor parameters can be changed by temperature and air-gap flux. In particular, the variation of the inductance affects torque characteristics like the maximum torque per ampere (MTPA) control. Therefore, by estimating the parameters, it is possible to improve the torque characteristics of the motor. The performance of the proposed estimator is verified by simulations and experimental results based on an 11kW PMSM drive system.