• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.5
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• pp.427-434
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• 2000

The paper proposes a zero speed start-up scheme of direct rector controlled induction motor drive without any torque jerk. At standstill condition, a method is derived to calculate a stator flux with only stator current. The programmable 3-stage low pass filters with programmable time constants is used in order to solute the problem of integration for stator flux estimation in the direct vector control mode. Due to the time delay of 3-stage low pass filter, the status flux decreases rapidly and also the torque jerk occurs during the transition from standstill mode to the direct rector control mode. A feedforward control strategy of the stator flux is suggested to prevent the torque jerk at start-up. Through results of simulation and experiment with 32 bit DSP, the performance of the start-up scheme is verified.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.4
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• pp.411-419
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• 2005

In this paper, a sliding mode observer for solar array current estimation in the photovoltaic power generation system is presented. The solar array current estimation Information is obtained from the sliding mode observer and fed into the maximum power point tracker to update the reference voltage. The parameter values such as inverter dc link capacitances cm be changed up to 50$\%$ from their nominal values and the linear observer can't estimate the correct state values under the parameter variations and noisy environments. The configuration of sliding mode observer is simple, but it shows the robust tracking performance against parameter variations and modeling uncertainties. In this paper, the method for constructing the sliding mode observer using equivalent control input is presented and the convergence of the proposed observer is verified by the Lyapunov method. The mathematical modeling and the experimental results verify the validity of the proposed method.

• Journal of the Korean Solar Energy Society
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• v.33 no.5
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• pp.69-75
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• 2013

To increase the efficiency of the photovoltaic, almost photovoltaic appliances are controlled by Maximum Power Point Tracking(MPPT). Existing most of the PV MPPT techniques have used power which multiplies sensed output current and voltage of the solar cell. However, these algorithms are unnecessarily complicated and too expensive for small and compact system. The other hand, the proposed MPPT technique is only one sensing of the MPPT converter's output current, so there is no need to insert another sensors of battery side. Therefore, this algorithm is simpler compared to the traditional approach and is suitable for low power solar system. Further, the novel proper charge/discharge algorithm for the battery with PV MPPT is developed. In this algorithm, there is CC battery charge mode and load discharge mode of the PV cell & battery dual. Also we design current control to regulate allowable current during the battery charging. The proposed algorithm will be applicable to battery included solar cell applications like solar lantern and solar remote control car. Finally, the proposed method has been verified with computer simulation.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.948-950
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• 2003

In this literature, the CMOS current mode fout quadrant differentiator circuit is proposed. The implementation is base on an appropriate input stage that converts the input current into a compressed voltage at the input capacitor ($C_{gs}$) of the CMOS driver circuit. This input voltage use as the control output current which flow to the output node by passing through a MOS active load and use it as the feedback voltage to the input node. Simulation results with level 49 CMOS model of MOSIS are given to demonstrate the correct operation of the proposed configuration. But the gain of the circuit is too low so the output differentiate current also low. The proposed differentiator is expected to find several applications in analog signal processing system.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.147-148
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• 2011

In this paper, implementation of digital control for critical conduction mode power factor correction (PFC) rectifier is presented. Critical conduction mode is widely used in medium and low power conversion application due to its minimized MOSFET turn-on loss and diode reverse-recovery problem. However, it needs additional zero current detection circuit and maximum frequency limit to properly turn the MOSFET on and avoid the excessive switching loss in light load operation. This paper explains the digital IC implementation and verifies its operation with 200-W prototype PFC rectifier.

• Journal of Power Electronics
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• v.18 no.1
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• pp.23-33
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• 2018

Silicon Carbide (SiC) MOSFET belongs to the family of wide-band gap devices with inherit property of low switching and conduction losses. The stable operation of SiC MOSFET at higher operating temperatures has invoked the interest of researchers in terms of its application to high power density (HPD) power converters. This paper presents a performance study of SiC MOSFET based two-phase interleaved boost converter (IBC) for regulation of avionics bus voltage in more electric aircraft (MEA). A 450W HPD, IBC has been developed for study, which delivers 28V output voltage when supplied by 24V battery. A gate driver design for SiC MOSFET is presented which ensures the operation of converter at 250kHz switching frequency, reduces the miller current and gate signal ringing. The peak current mode control (PCMC) has been employed for load voltage regulation. The efficiency of SiC MOSFET based IBC converter is compared against Si counterpart. Experimentally obtained efficiency results are presented to show that SiC MOSFET is the device of choice under a heavy load and high switching frequency operation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.521-524
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• 2009

Response to nerve stimulation platform for implementing measures to detect finger movement has been functioning as an important factor. This stimulated finger on the nerve and muscle responses would vary. In other words, the finger movement of the muscle response to nerve stimulation and sensing Actuator for the H/W development is needed. In addition, a low power embedded CPU based on the top was used. H/W configuration portion of the isolation power, constant current control, High impedance INA, amplifier parts, and the stimulus mode and the Micro-control the status of current, AD converter Low Data obtained through the processing system is implemented.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.310-315
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• 2008

Authors design a rotary-type small-scaled linear induction motor(LIM) and a performance test machine before manufacturing a real-scaled LIM for a railway transit. The designed LIM is a single-sided, short primary type and its primary has 4 poles. The rated power is 10(kW). In order to analyze characteristics of the LIM, authors use a mixed 2D-3D FEM analysis. 3-D FEM analysis is used for calculating a distribution of eddy-current on the semi-caped AL-sheet of the secondary reaction. Authors calculate a correction factor of conductivity and an equivalent conductivity on the secondary AL-sheet using a normalized eddy-current. The equivalent conductivity which is calculated in this way includes a transverse edge-effect of the LIM. Authors apply the equivalent conductivity on the secondary AL-sheet of 2D-FEM model and get performance characteristics of the LIM. Basic characteristics such as thrust and normal force, input current, efficiency and power factor of the LIM have been analyzed with the variation of frequency and speed. In order to apply an air-gap control system, the variation of the basic characteristics have been analyzed with the air-gap length variation of the LIM. Finally, authors introduce an operation mode using the air-gap control system and conduct a research on feasibility of the system.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.389-392
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• 2003

A use of micro processor having H-com functions is gradually increased, and this paper describes the digital servo controller applied to linear pulse motor The TMS320LF2407, made by TI(Texas Instruments Co.), is used as a arithmetic unit in control circuit, designed f3r motor drive and available for the implement of high performance and miniaturization. Also, it can allow the sufficient debugging and downloading into control board for independent operation. A current control in order to carry out a position control is of a digital current control mode, and its implement confirmed the servo control performance of position control.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.257-259
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• 2006

The paper is proposed maximum torque control of SynRM drive using adaptive learning mechanism-fuzzy neural network(ALM-FNN) controller and artificial neural network(ANN). The control method is applicable over the entire speed range and 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. The proposed control algorithm is applied to SynRM drive system controlled ALM-FNN and ANN controller, the operating characteristics controlled by maximum torque control are examined in detail. Also, this paper is proposed the analysis results to verify the effectiveness of the ALM-FNN and ANN controller.