Byong Jo Hyon

Implementation of VVVF drive for a three phase induction machine

This paper presents the design and implementation of induction machine drives by estimating a slip in fluid load and the Variable Voltage Variable Frequency (VVVF) drive scheme based on Sinusoidal Pulse Width Modulation (SPWM) technique for a three phase induction motor has been applied for use. The work involves implementation of a closed-loop control scheme for an induction motor. The VVVF technique is used extensively in the industry as it provides the accuracy required at minimal cost. For the slip estimation, a value of the stator flux is accordingly required. However estimating stator flux is complicated and even adopting flux sensors increase the cost. In this paper, complex and economic problems are solved by simplified slip estimation and VVVF control. The analysis is made with 3.2kW induction motor which used for fluid load. The implementation of VVVF drive applied simplified slip estimation is proposed and its validity is demonstrated by experimental results.

Development of motor control unit for induction machine of electric micro mobility

Electric vehicle appears to be one of the valuable solutions for environmental protection and the fast rate of depletion of world fuel oil supply. In particular, due to an increase in the elderly population and aging of a megacity, the need for electric micro mobility is even more apparent. Electric vehicles have serious disadvantages because of the limitation on cruising range imposed by weight, capacity of the electric accumulators and long recharging time. However the electric micro mobility is mainly focused on short-range movement and is personal transportation for one or two passengers. Improvement of efficiency and downsizing of motor control unit is an important issue in the micro mobility. In this paper, an electric micro mobility driving system is developed and the performance of the motor control unit is verified through tests. The evaluation is demonstrated experimentally.

Vector Control for Wave Power Generation System using Permanent Magnet Linear Synchronous Generator

파력발전은 파도의 위치에너지와 운동에너지를 이용한 발전방식으로 본 논문에서는 선형동기발전기를 이용한 파력발전시스템에 대하여 연구를 진행하였다. 파력 발전시스템을 분석하기 위해서는 부이의 운동과 부이와 연결과 발전기의 운동을 모델링하는 것이 매우 중요하다. 본 논문에서는 발전시스템의 분석을 위하여 선형발전기와 컨버터 시스템의 모델링을 진행하였다. 선형발전기와 컨버터 시스템의 전압 방정식 및 부이의 운동방정식을 이용하여 2상 회전좌표계에서의 벡터제어기법을 적용하여 댐핑기반의 제어기 구성을 제안한다. 파도 에너지로부터 전기에너지를 추출하기 위해서 파력발전기의 전류제어를 통해 댐핑을 적절히 조절할 수 있는 벡터제어기법 구성에 대해 제안한다. 최종적으로 제안된 제어기의 검증을 위하여 MATLAB/Simulink를 이용한 2상 회전좌표계에서의 벡터제어기의 시뮬레이션을 수행하였으며 선형 발전기 축소모델와 PCS 축소모델을 통한 실험을 수행하였다.

Development of single phase PFC module for electrostatic coating machine applications

Electrostatic sprayers to serve the agricultural, sanitization and industrial markets. Especially, in the automotive and aircraft applications electrostatic coating machine is widely used. The electrostatic coating is a manufacturing process that employs charged particles to more efficiently paint a workpiece. Paint, in the form of either powdered particles or atomized liquid, is initially projected towards a conductive workpiece using normal spraying methods, and is then accelerated toward the workpiece by a powerful electrostatic charge. Electrostatic coating system takes advantage of the principal of physics to achieve better coverage and to lessen the environmental impact by allowing smaller amounts of chemicals to be used. For the electrostatic coating system, high voltage generator is essential. In this paper, the authors developed and evaluated single phase power factor correction (PFC) module for the high voltage generator of electrostatic coating system.

Development of power conversion unit for automotive traction motor

Electric vehicle appears to be one of the available solutions for the growing concerns for environmental protection and the fast rate of depletion of world fuel oil supply. Electric vehicle can become a possible alternative to the internal combustion engine. However electric vehicles have serious disadvantages because of the limitation on cruising range imposed by weight, capacity of the electric accumulators and long recharging time. Improvement of efficiency of motor traction drives is an important issue in pure electric vehicles to improve the running distance on one charge [1]. In this paper, an electric vehicle driving system is developed and the performance of the inverter is verified through tests. The evaluation is demonstrated experimentally.