Kwang-Heon Kim

High step-up dc-dc converter with high efficiency for photovoltaic module integrated converter systems

A new high efficiency high step-up dc-dc converter is proposed for photovoltaic (PV) module integrated converter (MIC) systems. In the proposed converter, two transformers are utilized to double the voltage conversion ratio. Two resonant voltage doubler rectifiers are designed so that the output rectifying diodes are turned off at zero-current. A 260 W prototype was built and tested. Power efficiency of 97 % was obtained at the rated output power for 36 V input voltage.

Speed control method for switched reluctance motor drive using self-tuning of switching angle

In this paper, a determination method of turn-off angle is realized by using a self-tuning control method. During the sampling time, a number of pulses from the encoder are checked by using a single-chip microprocessor and then compared with a pre-checked number of pulses. After calculating the difference between the two data, the turn-off angle moves forward or backward by the self-tuning method. By repeating such a process, the optimal turn-off angle is determined and the maximum torque is maintained. Though experiments, it is observed that motor speed is almost maintained if the turn-off angle is adjusted automatically by a self-tuning method when turn-on angle is changed.

An Implementation of Vector Control of AC Servo Motor based on Optical-EtherCAT Network

In this paper we propose implement technique of vector current control in order to verify performance of an AC servo driver that is able to easy control of motion with multi-axis in the robot. In doing do, we have developed the AC servo driver to driving PMSM, and then we confirm that this driver whether operating or not normally by controlling of vector current. The vector current control was performed at the no load condition in PMSM. Then we compare command control and tracking control. As a result of verification, we recognize we get a satisfactory result.

BLDC Motor Control System using ASK DC-link PLC Technology

Power line communication or power line canier (PLC) is a system for carrying data on a conductor and can also used for electric power transmission. Now the powers used in the motor drive system are mostly DC sources. Even AC powers in some systems are generated from DC sources by the inverter. It is can be forecasted that the DC-link PLC technology will be widely used in various industrial fields. In this paper a novel BLDC motor control system using ASK DC-link PLC technology is proposed. The characteristic of this system is that the communication only needs 2 DC lines and there are no additional lines to translate the reference signals. The number of signal cables can be minimized when the DC-link PLC method is applied in the multi motor control system and the slip ring design also be simplified when this method is applied in rotation machines. The proposed motor control system is clarified by the PSIM and MATLAB simulations and tested through the hardware prototype.

Classification of materials using temperature response curve fitting and fuzzy neural network

Abstract This paper describes a system that can be used to classify an unknown material regardless of the change of ambient temperature using temperature response curve fitting and fuzzy neural network (FNN). There are some problems to realize the classification system using temperature response. It requires too many memories to store the vast temperature response data and it has to be filtered to remove noise which occurs in experiment. And the temperature response is influenced by the change of ambient temperature. So, this paper proposes a practical method using curve fitting to remove above problems of memories and noise. And FNN is proposed to overcome the problem caused by the change of ambient temperature. Using the FNN which is learned by temperature responses on fixed ambient temperature and known thermal conductivity (TC), the TC of the material can be inferred on various ambient temperature. So the material can be classified by the TC.

Zero-current soft-switching bidirectional DC-DC converter for high efficiency DC uninterruptible power supply

The usual way to avoid a computer shutdown during a mains failure is to connect an ac uninterruptible power supply (UPS). Alternatively, in this paper, a simple and high efficiency dc UPS is presented by proposing an isolated bidirectional soft-switching dc-dc converter. The bidirectional dc-dc converter operates under zero-current switching (ZCS) condition by utilizing the leakage inductor of the transformer. ZCS operation is achieved in battery-backup and charging modes which significantly reduces the power losses in the bidirectional converter. Also, high efficiency is achieved in backup and charging modes because there is only a single dc-dc conversion in each mode. A 1 kW prototype system has been built and tested for a PC power system.

Photovoltaic module integrated converter system minimizing input ripple current for inverter load

A high efficiency photovoltaic (PV) module integrated converter (MIC) system is proposed. The proposed system consists of a high step-up dc-dc converter and a single-phase full-bridge inverter. The proposed step-up dc-dc converter has a high efficiency and low-profile. An input ripple current reduction control is suggested to reduce the low frequency ripple current generated by the full-bridge inverter. Overall power efficiency of 95 % was obtained at 260 W output power for 36 V PV voltage with ripple current within 3 % of the rated input current.

Bi-Directional Optical-EtherCAT Communication for Motion Network Control of Humanoid Robot

Currently, most industrial automation systems and robotic systems require the high-speed transmission of data and highly precise control. We introduce a new communication protocol that is immune to...

Implementation of Vector Control of PMSM by Applying Optical-EtherCAT Communication for Robot

A key technology of the next generation robots is the ability to move with high speed, high precision and communication network control. We propose a vector control system by applying optical-Ether...

Manufacture and estimation of two phase driver for hybrid type linear pulse motor

It needs correct analysis of thrust for control performance improvement of HB-LPM (hybrid type linear pulse motor). It is difficult to analyze HB-LPMs thrust. In this paper, HB-LPMs thrust is expressed to mathematical expression (numerical formula). It is proved validity of this numerical formula by thrust measurement system. And it is proved once more validity of numerical formula by measuring waveforms of current and voltage which is supplied to each phase. In this study, we composed two phase driver. Advantage of this is that only one module of IPM which is accumulated by 6 elements of IGBT or MOSFET is possible in a driver structure. That can economize one module by comparing usual system. In other words, a driver structure is available by 4 elements of IGBT or MOSFET. This is economical big gain.