• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.107-108
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• 2012

This paper presents design and implementation of the LDC(1.8 kW DC-DC Converter for Electric Vehicles). For Implementation of the LDC, the adapted topology is ZVS(Zero Voltage Switching) PSFB(Phase Shift Full Bridge) with Digital Control is adopted. Also, for the purpose of stable operation of the LDC in vehicle with variable electrical load condition, Continuous Voltage and Current Limit Control scheme based on PI controller are developed. According to real-car test mode, the prototype of proposed the LDC is verified with performance and stability. Thus, optimizing design and implement of the LDC are discussed, and experimental results are presented.

• Proceedings of the KIEE Conference
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• 2001.07e
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• pp.116-119
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• 2001

In this research, we detect the charge state within $0.1{\sim}0.3[A]$ and develop the intelligent digital charge device by applying a fine pulse signal using PWM inverter and Proportional-Integral(PI) controller which uses micro -processor and intelligent technique. The ripple rate is within ${\pm}1%$, and the indicator error rate of full charge state is within ${\pm}1%$, and the voltage stability is within ${\pm}0.1[V]$, and the accuracy of voltage detect is 48[V] and ${\pm}0.5[V]$ in the reference of 100[A].

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.2
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• pp.183-190
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• 2007

In this paper, a robust controller for PWM converter is proposed. The proposde converter controller consists of a PI controller for DC output voltage and a current controller using error-space approach for maintaining the sinusoidal current waveform and unity power factor. Conventionally, the try and error method has been used to design the current controller considering the switching frequency of the devices and sampling frequency of the digital controller. But this proposed method is based on characteristic ratio assignment(CRA) method which has the advantage to design the optimal gain to meet the referenced response and overshoot within the limit range. First, the CRA based current controller algorithm is explained. Then the validity of proposed controller is verified through the PSiM simulation and experience results.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.846-848
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• 1995

Recently, direct drive AC servo motor and DSP is widely used in the factory automation and related field due to the enhanced control and digital technology. In this paper, position control of direct drive AC servo motor and numerical interpolation algorithms are studied using DSP for the future applications. In the direct drived motor control, encoder pulse is divided into the quadruple pulse for the higher resolution and high speed pulse(10MHz) is used as reference for the slower speed motor control (M/T method). As for the general position control, PI controller is adapted for position control. In the trajectory tracking numerical algorithm, interpolation of straight line and curve algorithms are studied for the realization of path following capabilities of XY table. As for the DSP, ADSP 2105 is selected for the economy and performance points of view.

• Journal of Practical Engineering Education
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• v.10 no.1
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• pp.9-15
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• 2018

A digital signage is constructed using a speech recognition based API, and VRSM (Voice Recognition Smart Mirror) that obtains information such as weather, map, exercise information, schedule, and image by user's voice command so as to be different from other commercialized products is proposed. This course provides an effective method of engineering education through the process of being evaluated as the result of independent graduation certification system, and also it had been the opportunity to design and produce works for 3 semesters by 2 students one group in the majors. Through the comprehensive capstone design, it has experienced engineering approach and creative thinking opportunity. We have won the best academic prize by participating in the academic conferences of the institute about the interim result, and obtained the results of the prize contest in other academic conferences. The improvement in practical skills obtained through this process proved to be beneficial for self-confidence and job-seeking opportunities through actual employment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.959-962
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• 2005

Servomotors are used as key components of automated system by performing accurate positioning, accurate speed regulation, and precise motion control in response to commands from computers and sensors. Especially linear brushless servomotors have numerous advantages over ball screws, timing belts, rack/pinion drives and friction drives compared with rotary servomotors. This paper proposes the estimation of unknown parameters from the linear brushless DC motor which is operated by sinusoidal commutation. The estimated parameters are used to tune the controller gain and disturbance observer. In order to agree with this purpose, Digital Signal Processor(TMS320F240), developed for implementation of a speed Field Oriented Control(FOC), adopted in this study. The processor playing an important role in controller has A/D converters, PWM generators, riched I/O port internally.

• Journal of Broadcast Engineering
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• v.26 no.4
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• pp.377-389
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• 2021

This paper presents a framework design of a digital twin system for a vertical smart farm. In this paper, a framework of digital twin systems establishes three factors: 1) Client 2) IoT gateway, and 3) Server. Especially, IoT gateway was developed using the Eclipse Ditto, which has been commonly used as the standard open hardware platform for digital twin. In particular, each factor is communicating with the client, IoT gateway, and server by defining the message sequence such as initialization and data transmission. In this paper, we describe the digital twin technology trend and major platform. The proposed design has been tested in a testbed of the lab-scale vertical smart-farm. The sensor data is received from 1 Jan to 31 Dec 2020. In this paper, a prototype digital twin system that collects environment and control data through a raspberry pi in a plant factory and visualizes it in a virtual environment was developed.

• Journal of the Semiconductor & Display Technology
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• v.3 no.1
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• pp.21-26
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• 2004

Recently with the development of power switching device and DSP which has peripheral devices to control AC servo system, the servo technology has met a new development opportunity. Those things make it possible to reduce the time of developing a AC servo system. Fixed point DSP such as TMS320F240x, and TMS320F28x series have a disadvantage in calculating floating number where TMS320C32 or TMS320C31 are floating point DSP. However they usually become a complex hardware system to implement the AC servo system and it increases the cost. In this study, a DSP based AC servo system with a 3-phase PMSM is proposed. The newly produced DSP TMX320F28l2-version C which has the performance of fast speed, 150MIPS, and a rich peripheral interface such as a 12bit high speed AD converter, QEP(Quadrature Encoder Pulse) circuit, PDPINT(Power Drive Protect Interrupt), SVPWM module and dead time module are used. This paper presents a method to overcome fixed point calculating using scaling all parameters. Also space vector pulse width modulation (SVPWM) using off-set voltage and a digital PI control are implemented to the servo system.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.595-602
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• 1994

PERISTOR-3000 loaded with 32 bit DSP(Digital Signal Processor) is a technically advanced versatile dc motor controller in applications with very high requirements for rapid response, control accuracy and reliability. The current controller of PERISTOR-3000 is of the predictive type and gives fast control with both discontinuous and continuous current compared to the conventional PI current control. The speed controller gain is compensated to improve response behavior. PERISTOR-3000 communicates with its host computer, POSTAR-3200, or any IBM or compatible PC and can be controlled. Dedicated monitoring system for MMI is introduced.

• Journal of Electrical Engineering and Technology
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• v.12 no.6
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• pp.2227-2236
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• 2017

In order to solve the neutral-point voltage fluctuation problem of three-phase three-level T-type inverters (TPTLTIs), the unbalance characteristics of capacitor voltages under different switching states and the mechanism of neutral-point voltage fluctuation are revealed. Based on the mathematical model of a TPTLTI, a feed-forward voltage balancing control strategy of DC-link capacitor voltages error is proposed. The strategy generates a DC bias voltage using a capacitor voltage loop with a proportional integral (PI) controller. The proposed strategy can suppress the neutral-point voltage fluctuation effectively and improve the quality of output currents. The correctness of the theoretical analysis is verified through simulations. An experimental prototype of a TPTLTI based on Digital Signal Processor (DSP) is built. The feasibility and effectiveness of the proposed strategy is verified through experiment. The results from simulations and experiment match very well.