Taehyung Kim

This paper presents a new approach to analyze the stator inter-turn fault of a brushless dc motor. It is essential to analyze the behavior of the machine under internal faults and design appropriate protection systems to avoid expensive failures that might occur to the machine in the near future. The winding functions and inductance change of stator windings under internal faults are explained in detail, and the informative simulation results, based on the winding function theory, are provided t

This paper presents the theory and practice required to implement a novel sensorless operation technique for the brushless DC (BLDC) motor. The proposed new sensorless drive method breaks through the chronic problem of the sensorless BLDC motor drives, lack of low speed operation, so that it ensures highly accurate, robust sensorless operation from near zero to high speed. For this purpose, a physically insightful, speed-independent function, based on a new flux linkage function, is used. A simu

Recent advances in the development of fast digital signal processors (DSPs) have paved the way for sensorless drive techniques of AC motors. The sophisticated sensorless algorithms in DSPs substitute for the mechanical position sensors and other hardware. This paper covers an entire range of topics related to the position sensorless control of brushless DC (BLDC) motor and generator drives including their fundamentals, limitations, present advances, and future trends. The main purpose of this pa

In this paper, the advanced control methods to minimize torque ripple and to maximize power density of a brushless DC (BLDC) motor/generator system in electric vehicles (EVs) and hybrid electric vehicles (HEVs) are presented. A simple and straightforward torque ripple control method with copper loss minimization for BLDC machines is proposed first. Then, an optimal power control to maximize power density and minimize machine size and weight for non-sinusoidal BLDC machines is explained for gener

This paper presents a novel sensorless operation technique for brushless DC (BLDC) motors and a new approach of error analysis for the sensorless BLDC motor drive. The analysis breaks down the estimated position error to its fundamental elements in the BLDC motor drive system. The position estimation error decreases the motor efficiency and produces torque pulsation. In this paper, the new approach is introduced to analyze the errors inherent in sensorless drive systems. The analysis method pres

This study presents a new multi‐functional control system for a multi‐port energy converter that interfaces one bi‐directional battery port, one dc input port, and three output ports. Only one single‐leg active switching element (a module type can be used) is employed in the system, and hence the single leg requires digital switching signals for a multi‐functional operation to regulate output voltages and to simultaneously manage the battery port. The proposed system has buck–boost conversion ca

This paper presents switch fault detection and compensation control schemes for a modified dc-dc converter that relocates a diode location. The proposed fault detection and compensation control schemes are applicable to various energy generation systems that include energy storage. A fault detection index has been introduced to detect an open switch fault in the modified converter structure, and a compensation control method based on a mixed switching strategy has been developed. The fault-toler

Due to an increasing in-vehicle electric load demand, a new 48-V electric system architecture proposed by German premier car manufacturers has been gaining increasing attention recently for electrified vehicles. In this paper, a multiple-voltage bus converter for the 48-V and existing 12-V dual supply system, providing additional flexible dc bus voltages, is proposed. The proposed converter can provide a dual flexible dc voltage bus and an additional dependent voltage bus while simultaneously ma

In this article, the structure and control of a fuel cell hybrid electric scooter for mass production are presented. The development of a zero-emission scooter can improve air quality and protect the environment, especially in Asia and Europe, where more than 25 million scooters are produced annually. The generic advantages of low-pressure hydrogen storage of the fuel-cell-powered scooter are explained, and the control strategies of the hybrid scooter are presented. Additionally, experimental ve

Abstract In this article, the regenerative braking control of a permanent magnet motor/generator in a light fuel cell hybrid electric vehicle is presented. The control strategies for motoring and regenerative braking operations of a permanent magnet motor are explained in detail based on a hybrid power system control. Based on the proposed method, a simulation is performed to verify the approach. In addition, a prototype experimental test-bed is built for experimental verification, and the resul

The objective of this paper is to analyze and identify the range of voltage balancing capability of grid-forming inverters serving three-phase unbalanced loads. These inverters are designed to compensate for voltage imbalance by controlling the negative-sequence components of voltage and current. However, the magnitude of the negative-sequence current an inverter can supply is limited by its relatively low rated current. Moreover, it becomes more challenging to estimate the amount of current nee

Car-following models have been used in all microscopic traffic simulation modeling for almost half a century to describe the process of driver behavior in following each other in the traffic stream. In recent years, a detailed understanding of car-following behavior has become more essential for both the design and the assessment of advanced driver assistance systems, such as adaptive cruise control, to help improve appropriate algorithms and develop control strategies. However, previous experim

In this research, we propose an Integrate-and-fire (I&F) Silicon-on-insulator (SOI) neuron circuit incorporating a Schmitt trigger as an action potential generating component. The Schmitt trigger is composed of four MOSFETs, and it presents hysteresis by controlling the threshold of one of the four MOSFET using back-gate effect. The presented circuit effectively handles input overflow by modulating output pulse duration, thus maintaining Rectified-linear-unit (ReLU) equivalence of I&F spiking ne

<div class="htmlview paragraph">The ride values of seven cars(six passenger car and one RV car) are evaluated for 4 subjects based on the vibration of the bodies. And the seat qualities are investigated with the SEAT(seat effective amplitude transmissibility) value. The evaluated values are arranged as DB in html files. Since one of the most important parameters for ride comfort is the level and duration of the root mean square acceleration experienced, the acceleration responses of subjec