• Journal of Electrical Engineering and Technology
• /
• v.12 no.2
• /
• pp.778-789
• /
• 2017

This paper presents an improved subdomain method to predict the magnet field distributions and electromagnetic performance of the surface-mounted permanent magnet (SPM) machines with static or dynamic eccentricity. Conventional subdomain models are either based on the scalar magnet potential to predict the rotor eccentricity effect or dependent on the magnetic vector potential without considering the eccentric rotor. In this paper, both the magnetic vector potential and the perturbation theory are introduced in order to accurately calculate the effect of rotor eccentricity on the open-circuit and armature reaction performance. The calculation results are presented and validated by the corresponding finite-element method (FEM) results.

• Proceedings of the KIPE Conference
• /
• 2001.10a
• /
• pp.566-570
• /
• 2001

Generally, grounding systems are responsible for the safe operation of a power system. Their performance guarantees equipment protection and personnel safety under condition of the limited ground potential rise and touch voltages as well as step voltages under ground fault conditions. Therefore, it is necessary to measure the ground resistance frequently for checking the performance of grounding system, In this paper the ground resistance measuring system using digital signal processor and high-performance L-C resonant band pass filter is presented. The signal current magnitude for measuring ground resistance in this system is $10^{-1}[A]\;to\;5\times10^{-2}[A]$ and the current frequency is 30[Hz].

• Journal of Electrical Engineering and Technology
• /
• v.10 no.4
• /
• pp.1796-1803
• /
• 2015

While considering the current scenario, in this world power demand goes on increases day by day. Frequent power outages occur in high voltage transmission line due to the deprived performance of polluted insulators; this affects overall operation of power system and may indirectly impinge on the growth of production sector. Many researchers are keenly taking efforts to provide highly reliable and stable power to neediest. In this paper, A.C pollution flashover performance of disc type glass insulator and composite long rod insulators investigation under various artificial pollutions by varying Equivalent Salt Density Deposition (ESDD) levels. Here, we use different types of pollution methods like binding method, dipping method and spraying methods with different types of pollutants concentration. Based on dimensional analysis, four different Mathematical models have been developed to predict the A.C pollution Flashover Voltage (FOV) of insulators. Both the experimental and mathematically modeled results are compared; it's observed that mathematical model 3 yields better results.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.4
• /
• pp.1635-1645
• /
• 2015

This study proposes high-performance voltage controller design that employs a capacitor current control model for single-phase stand-alone inverters. The single-phase stand-alone inverter is analyzed via modeling, which is then used to design the controller. A design methodology is proposed to maximize the bandwidth of the feedback controller. Subsequently, to compensate for the problems caused by the bandwidth limitations of the controller, an error transfer function that includes the feedback controller is derived, and the stability of the repetitive control scheme is evaluated using the error transfer function. The digital repetitive controller is then implemented. The simulation and experimental results show that the performance of the proposed controller is high in a 1.5 kW single-phase stand-alone inverter prototype.

• Journal of Electrical Engineering and Technology
• /
• v.3 no.3
• /
• pp.308-313
• /
• 2008

This article proposes the study and simulation of an RST regulator based on a double fed induction machine. The RST polynomial controller can improve the double fed induction machine performance in terms of overshoot, rapidity, cancellation of disturbance, and capacity to maintain a high level of performance. A control law is synthesized using an RST controller. Simulation results indicate that the proposed regulator has better performance response to speed variation, sensitivity to perturbation, and robustness. The designed control algorithm is tested on a simulation matlab code.

• Journal of Electrical Engineering and Technology
• /
• v.12 no.5
• /
• pp.1980-1990
• /
• 2017

A study on the multi-objective optimization of Interior Permanent-Magnet Synchronous Motors (IPMSMs) with 2, 3, 4 and 5 flux barriers per magnetic pole, based on Genetic Algorithm (GA) is presented by considering the aspect of irreversible demagnetization. Applying the 2004 Toyota Prius single-layer IPMSM as the reference machine, the asymmetrical two-, three-, four- and five-layer rotor models with the same amount of Permanent-Magnets (PMs) is presented to improve the torque characteristics, i.e., reducing the torque pulsation and increasing the average torque. A reduction of the torque pulsations is achieved by adopting different and asymmetrical flux barrier geometries in each magnetic pole of the rotor topology. The demagnetization performance in the PMs is considered as well as the motor performance; and analyzed by using finite element method (FEM) for verification of the optimal solutions.

• Proceedings of the KIEE Conference
• /
• 1999.07f
• /
• pp.2786-2788
• /
• 1999

In this paper, a mixed mode exciting resonant inverter topology applicable to high performance electronic ballast is presented. Mixed mode exciting technique combines the attractive features of self exciting resonant inverter with those of external exciting one. The control IC is designed and manufactured by using a 0.8um CMOS process for 5V operation and has only 8 pins. This performs the operations of filament preheating, dimming control, output power regulation and protections. The mixed mode exciting resonant inverter with control IC has very simple structure, high performance and expensive manufacturing cost.

• 제어로봇시스템학회:학술대회논문집
• /
• 1992.10b
• /
• pp.458-462
• /
• 1992

This paper presents a decomposition method to evaluate the performance measures of transfer line with unreliable machine and finite buffers. The proposed method is to decompose the transfer fine into a set of two machine lines for analysis. Nonhomogeneous lines are considered. In such fines, the machines may take the different lengths of time performing operations on parts. A simple transformation is employed in order to replace the line by a homogeneous line. The approximate transformation enables one to determine parameters of performance such as production rate and average buffer levels, and it also shows better applications for a large class of systems.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.4 no.2
• /
• pp.254-258
• /
• 2004

In this paper, we propose a robust speech recognition system under noisy environments. Since the presence of noise severely degrades the performance of speech recognition system, it is important to design the robust speech recognition method against noise. The proposed method adopts a new distance measure technique based on stochastic probability instead of conventional method using minimum error. For evaluating the performance of the proposed method, we compared it with conventional distance measure for the 10-isolated Korean digits with car noise. Here, the proposed method showed better recognition rate than conventional distance measure for the various car noisy environments.

• Transactions on Electrical and Electronic Materials
• /
• v.7 no.3
• /
• pp.134-140
• /
• 2006

The effect of surface treatment of fillers on the mechanical, electrical properties, and tracking performance of silicone rubber insulators have been investigated. For base polymer, $\alpha,\;\omega$) vinyl poly(dimethyl-methylphenyl) siloxane(VPMPS) containing dimethyl siloxane and methylphenyl siloxane was prepared by the equilibrium polymerization. High voltage silicone rubber composites(HVSRC) were prepared from VPMPS, nano-silica, and alumina trihydrate (ATH) modified by various coupling agents. Bound rubber of uncured silicone rubber, cross-linking density of the vulcanizate as well as the mechanical, electrical properties, and tracking performance were measured.