Han-Seok Park

DSSCs Efficiency by Thickness of TiO 2 Photoelectrode and Thickness Differences Between Two Substrates

DSSCs efficiency by thickness of photoelectrode and thickness differences between two substrates studied. DSSCs is made of the doctor blade method and photoelectrode annealing temperature elevated in a different ways. In addition, cells efficiencies of according to the different thickness between photoelectrode substrate and Pt counter electrode was measured. Efficiency of DSSCs made with photoelectrode of 18 thickness and the gap difference between the substrate 28 shows a highest 4.805% efficiency.

Improvement of torque characteristics of permanent magnet wind generator by FEM and optimization

This paper focuses on the improvement of the torque characteristics of the outer rotor direct drive permanent magnet wind generator that is a radial flux machine with output power of low speed and high torque, 3(kW) 90(rpm) by FEM and optimization. The optimization technique is used to find out a design solution through the comparison of cogging torques according to the shape variation such as the open slot width and the pole arc ratio. In this technique the problem is to mini mize the objective function. The automatic process that includes the automatic ACAD file drawing and mesh generation with reg ard to the shape variation is also used. The revised generator is obtained from a preliminary model. The cogging torque characteristics of the revised model and the preliminary model and the dynamic characteristics are analyzed. From the simulation result s, it is shown that the cogging torque characteristic of the revised model is better than that of the preliminary one. The prototype was manufactured and the simulation result such as induced voltage is agrees with that of the experimental one.

Development of New Conveyer Directly Driven by Contact-less Energy Transmission System

This paper focuses on development of new conveyer directly driven by the contact-less energy transmission system. The effect of the resonant circuit and the flux linkage characteristics caused from that are analyzed by using 3D finite element analysis. From the result it is shown that the resonant circuit needs to transfer energy from the primary core to the secondary core. Also the influence of the linear induction motor on the contact-less energy tansmission system is presented. New conveyer and the experimenta1 apparatus was manufactured by using the contact-less energy transmission system and the linear induction motor. Possibility of realization of the conveyer is proved by comparison the simulation result which is obtained by using 2D finite element analysis with experimenta1 one and the characteristic of the voltage and resonant current.

Study on the Evaluation of Uncertainty for the Efficiency of 0.75[kW] Class Three Phase Induction Motor

In the last few years, the regulations for efficiency grade of the three phase induction motor are internationally being discussed and upgraded for the protection of environment and energy saving. So the efficiency improvement and the reliable test result are essential to determine the premium grade three phase induction motor. While a study on developing the efficiency motor is active, there is little research about the guarantee for efficiency. So in this paper, the dispersion characteristic of the efficiency is studied using uncertainty theory for the three phase induction motor to improve the reliability of efficiency. The values such as input voltage, current, speed, torque were obtained by loss separation method to evaluate the uncertainty. From the result, it was known that the important loss factor could affect the uncertainty is the stray loss.

Improved back-EMF of 30kW Interior Permanent Magnet Synchronous Generator for Small Hydropower Generation

This paper presents the improved back-EMF of Interior Permanent Magnet Synchronous Generator(IPMSM) for small hydropower generator. To improve back-EMF characteristics, the size and position of notch are applied to the rotor. In addition, parametric analysis of the notch size and position was performed. Finally, the back-EMF characteristic analysis are confirmed by the experimental results.

Characteristics of Maximization Output Control for Variable Wind Generation System Using IPMSG

This paper proposes the variable wind generation system based on the direct torque control(DTC)for the interior permanent magnet synchronous generator. The proposed system can achieve the MPPT control without wind speed in addition to the speed and position sensorless control as well as the conventional current control method. The DTC has several advantages such as simply system configuration, ease of the flux weakening control and the sensorless control. The experimental results show the performance of the proposed wind generation system.

Power Balancing Control Method of A Residential Distributed Generation System using Photovoltaic Power Generation and Polymer Electrolyte Fuel Cells

Output power in photovoltaic systems changes steeply with the change of the sun intensity. The change of output power has influence on the electric power quality of the system. This paper proposes a residential distributed generation system using photovoltaic power generation and polymer electrolyte fuel cells(hybrid systems). In order to level the output power which changes steeply the polymer electrolyte fuel cells are connected to the photovoltaic power generation system in parallel. Thus the generated power of all the system can be leveled. However, the steep generated power in the photovoltaic power generation system can not be leveled. Therefore, the electric double layer capacitor(EDLC) is connected in parallel with the hybrid systems. It is confirmed by the simulation that the proposed distributed generation system is available for a residential supply.

A Study on the Efficiency Evaluation Standard and Regulation for Electric Motor Systems

Electric motor systems account for more than half of all electric systems and the amount of energy consumption of those is almost 70 percent of total energy consumption of electric motor systems in industry. As electric motor systems are very responsible for global electricity savings and environment protection. Many international organizations are supporting standards and policy development processes to improve the efficiency of electric motor systems. Many standards are being developed at technical committee of IEC that has been required in order to support the implementation of efficiency regulations. High efficiency standards and levels for electric motor systems are slowly being introduced and compulsory in many countries. Therefore understanding the international efficiency evaluation standards and the regulation of electric motor systems of each country is important. This paper presents the current status and trends of international evaluation standards and regulations about the efficiency of electric motor systems.

New Partial Resonant Zero Voltage Switching PWM High Frequency Inverter using Induction Heating

This paper presents a newly proposed prototype of voltage-fed half-bridge partial resonant zero voltage switching PWM inverter operating at a constant frequency variable power regulation scheme, which is more suitable and acceptable for induction heated(IH) cooking appliances. This application-specific high frequency inverter circuit topology using a new generation specially-designed IGBTs can operate under a principle of a fixed frequency ZVS-PWM strategy. The operating principle of a new partial resonant inverter circuit is described on the basis of its computer-aided simulation analysis, its including steady-state operating characteristics.

The Topology of Novel Soft Switching Boost Rectifier

This paper has proposed a new boost rectifier. Adequate input current was obtained by keeping the duty ratio constant without complicated conventional control methods and the improvement of the waveform was increased. With a decrease of distortion up to 12.9[%], the scope of restriction on harmonics was set to 13.0[%]( harmonics), 1.1[%]( harmonics) and 0.6[%]( harmonics), respectively. Because complicated methods of control are avoided, the circuit configuration is simple and practical. In particular, the said effect turned out to be highly efficient in the low boosting ratio range(boosting ratio). The feasibility of these facts has been proven both theoretically and experimentally.