• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.2
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• pp.118-126
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• 2020

A solar array simulator is a special power supply that regulates the output voltage and current to simulate the characteristics of a photovoltaic panel. The operating point of the panel is difficult to control with a single controller because of the non-linearity of the output curve, which is determined by the amount of irradiation, temperature, and panel material. In the conventional method, the output curve is divided into sections through the current and the voltage mode controls. It reduces the overall performance of the system due to the interchanging control mode. By using the single mode controller, the noise interference of the measured value and the stability of the control around the maximum power point were demonstrated. To solve these issues, this study proposes a new unified controller. The stability of the controller was analyzed along with operating principles, and performance improvement was experimentally verified.

• Journal of the Korean Society for Railway
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• v.2 no.2
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• pp.39-45
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• 1999

This paper presents the current-fed inverter of a TGV-K traction system with thyristor switches using phase control and commutation techniques. The current-fed inverters have two modes of operation which consist of forced commutation and natural commutation. In forced commutation mode, at speed of less than 120km/h, commutation is forced by means of the commutation capacitors and the thyristors. Above 120km/h, the thyristors operate in natural commutation mode. according to the voltages between phases of the motors. In this paper. the power conversion theory of the TGV-K traction system and the control principle of the converter and current-fed inverter are discussed.

• Proceedings of the KSR Conference
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• 1999.05a
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• pp.275-282
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• 1999

This paper presents the current-fed inverter of a TGV-K traction system with thyristor switches using phase control and commutation techniques. The current-fed inverters have two modes of operation which consist of forced commutation and natural commutation. In forced commutation mode, at speed of less than 120km/h, commutation is forced by means of the commutation capacitors and the thyristors. Above 120km/h, the thyristors operate in natural commutation mode, according to the voltages between phases of the motors. In this paper, the power conversion theory of the TGV-K traction system and the control principle of the converter and current-fed inverter are discussed.

• Journal of Electrical Engineering and Technology
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• v.5 no.1
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• pp.171-178
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• 2010

Resonant parametric perturbation (RPP) method is an effective non-feedback method for controlling chaos. In this paper, the above method is applied for the current programmed buck-boost dc-dc converter which exhibits chaotic for wide parameter variations. The different possible operating regimes leading to chaotic operation of the current mode controlled buck-boost converter is discussed and the control of chaos by RPP method is demonstrated through computer simulations and experimental studies. The converter is stabilized to period 1 operation practically.

• Journal of Power Electronics
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• v.17 no.2
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• pp.464-475
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• 2017

This study examines a P+multi resonant-based voltage control for voltage harmonics compensation under the islanded mode of a microgrid. In islanded mode, the inverter is defined as a voltage source to supply the full local load demand without the connection to the grid. On the other hand, the output voltage waveform is distorted by the negative and zero sequence components and current harmonics due to the unbalanced and nonlinear loads. In this paper, the P+multi resonant controller is used to compensate for the voltage harmonics. The gain tuning method is assessed by the tendency analysis of the controller as the variation of gain. In addition, this study analyzes the slight voltage magnitude drop due to the practical form of the P+multi resonant and proposes a counter method to solve this problem by adding the PI-based voltage restoration method. The proposed P+multi resonant controller to compensate for the voltage harmonics is verified through the PSIM simulation and experimental results.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1154-1156
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• 2001

This paper presents the implementation of a positon sensorless vector control system of a PM linear synchronous motor by sliding mode observer based on TMS320F240 DSP controller. Sliding mode observer estimates the secondary velocity and position based on the measurement of current, and it shows very robust characteristic to parameter variation. Therefore, it improves the system performance deterioration caused by system parameter variations. Simulation and experimental considerations are presented to confirm the applicability of sliding mode observer to the sensorless position control of PMLSM.

• Journal of Power Electronics
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• v.19 no.6
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• pp.1403-1412
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• 2019

A coupled inductor-dual boost-inverter (CIDBI) with a differential structure has been presented for application to a micro-inverter photovoltaic module system due to its turn ratio of a high-voltage level. However, it is difficult to design a CIDBI converter with a conventional PI regulator to be stable and achieve good dynamic performance, given the fact that it is a high order system. In view of this situation, a sliding mode control (SMC) strategy is introduced in this paper, and two different sliding mode controllers (SMCs) are proposed and adopted in the left and right side of two Boost sub-circuits to implement the corresponding regulation of the voltage and current. The schemes of the SMCs have been elaborated in this paper including the establishment of a system variable structure model, selection of the sliding surface, determination of the control law, and presentation of the reaching conditions and sliding domain. Finally, the mathematic analysis and the proposed SMC are verified by experimental results.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.57-58
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• 2010

This paper proposes maximum torque control of IPMSM drive using optimal current. This control method is applicable over the entire speed range which considered the limits of the inverter's current and voltage rated value. For each control mode, a condition that determines the optimal d-axis current $i_d$ for maximum torque operation is derived. This paper considers the design and implementation of novel technique of high performance speed control for IPMSM using multi-MFC and ANN controller. Also, this paper proposes maximum control of IPMSM drive using approximation method. This method is decreased the burden of digital signal process(DSP) in calculation of optimal current. This paper proposes the analysis results to verify the effectiveness of the MFC and ANN controller. Also it verifies the validity of maximum torque control of IPMSM drive with optimal current.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.528-533
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• 2004

The purpose of this thesis is to construct the autonomous decentralized train traffic management structure using techniques of Autonomous Decentralized System. Currently, a method of train traffic control is making use of CTC(Centralized Traffic Control). Its operation method is divided into the remote mode and the local mode. The classified basis is according to the control authority of install signals in track side. In most cases, a large scale station is operated by the local mode. Because of dispatchers in center can not control the shunting works influence on the main route. In order to solve these problem s, we analyzed a current operation condition and system requirements. Moreover, this thesis is constructing autonomous decentralized train traffic management structure. Finally, this research proposed that interface with CTC and step-by-step construction.

• Journal of Electrical Engineering and Technology
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• v.10 no.6
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• pp.2307-2314
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• 2015

In this paper, a discontinuous conduction mode (DCM) frequency control algorithm is proposed to reduce the input current ripple of a multi-phase interleaved boost converter. Unlike conventional variable duty and constant frequency control, the proposed algorithm controls the switching frequency to regulate the output voltage. By fixing the duty ratio at 1/N in the N-phase interleaved boost converter, the input current ripple can be minimized by ripple cancellation. Furthermore, the negative effects of the diode reverse recovery current are eliminated because of the DCM characteristic. A frequency controller is designed to employ the proposed algorithm considering the magnetic permeability change. The proposed algorithm is analyzed in the frequency domain and verified by a 600 W three-phase boost converter prototype that achieved 57% ripple current reduction.