Taeck-Kie Lee

A three-phase parallel active power filter operating with PCC voltage compensation with consideration for an unbalanced load

The performance and dynamic characteristics of a three-phase parallel active power filter (APF) with point of the common coupling (PCC) voltage compensation with consideration for an unbalanced load is presented and analyzed in this paper. The proposed scheme employs a pulse-width modulation (PWM) voltage-source inverter and has two operation modes. First, it operates as a conventional active filter with reactive power compensation when PCC voltage is within the 15% voltage drop range. Second, it operates as a voltage compensator when PCC voltage is not within the 15% voltage drop range. Both the APF and the voltage compensator compensate asymmetries caused by nonlinear loads. Finally, the validity of this scheme is investigated through the analysis of simulation and experimental results for a prototype APF system rated at 10 kVA.

An efficient battery charging algorithm based on state-of-charge estimation for electric vehicle

This paper proposes the off-line battery charger for electric vehicle. In order to charge the battery for EV, the safety and charging time must be contemplated. Also battery charger requires that it is a capable of the high power capacity. Therefore, three-phase AC-DC boost converter is suitable for the off-line battery charger. It can transform from the three-phase utility input to DC output without additional rectifier circuit. The power factor correction can be implemented by the phase control by the Parks transformation. With the hardware system of the charger, the battery charging algorithm is important for the development of the charger. The battery charging algorithm is required to reduce the charging time and prevent the overcharging. In this paper use the Constant voltage-Constant current charging method is adapted for safely charging battery. However, it takes a long time for fully charging the battery, so this paper presents the improved CC-CV charging method. It helps reduce the total charging time. It is described by comparison of conventional CC-CV method and verified through the experimental results.

Battery charging system for PHEV and EV using single phase AC/DC PWM buck converter

In this paper, a battery charging system for Plug-in Hybrid Electric Vehicle (PHEV) and Electric Vehicle (EV), and operation algorithm of charging system is introduced. Also, the proposed charging system uses commercial electricity in order to charge the battery of parked PHEV, and 48V battery charging system with power factor controllable single phase converter for PHEV is investigated in this paper. This research verifies the power factor control of input and the converter output controlled by the charge control algorithm through simulation and experiment.

Position control of PMSM using jerk-limited trajectory for torque ripple reduction in robot applications

In the modern industry, the motor control is required for the accurate position control. Particularly, the frequent acceleration and deceleration are operated in the robot control. Also, the short time of acceleration and deceleration is demanded for the reduction of process cycle. However, in case the inertia of motor is large, the vibration of motor is occurred in the section of short acceleration and deceleration. Therefore, the algorithm of position pattern is considered for the condition of the optimal drive. In the section of short acceleration and deceleration, the vibration of motor is reduced by the S-curve output of speed pattern. In this paper, the position reference in consideration of jerk is generated in the control system of permanent magnet synchronous motor (PMSM). The reduction of vibration occurred in acceleration and deceleration of motor is verified through the simulation and experimental results.

Phase current sensing method using three shunt resistor for AC motor drive

This paper proposes a novel method for reconstructing three phase inverter phase currents using the information from shunt resistors. To control the instantaneous torque when controlling SVPWM to drive AC motor, the phase current information is essential. A method using shunt resistor is one of the phase current sensing methods needed to drive AC motors. One advantage of a phase current sensing method using shunt resistor is it is possible to configure the sensor part at comparatively lower cost than a sensing method using hall sensor. Sensing methods using shunt resistors include: a sensing method applying each shunt resistor to the bottom of three-phase inverter switch arm and a sensing method applying each shunt resistor to the bottom of DC-Link. This study defines the area where it is not possible to detect the current generated during the detection of phase current three-phase inverter, using the area where it is not possible to detect the current, and then verifies that through simulation.

Grid-Connected Electric Vehicles Charger Station Based on Lithium Polymer Battery Energy Storage System

This paper proposes the 10kW class grid connected power station with high discharge current characteristics based on the lithium polymer battery for electric vehicles charger station. The lithium polymer battery has faster discharge current characteristics than that of the conventional battery, so that can compensate high active power demanded by the load in a short time using the low capacity battery bank. Therefore, it is possible to control power leveling of grid by measuring storage energy of battery and active power which is needed from the load. The validity of proposed system was verified through the simulation and experiment.

Control of IPMSM for Hybrid Electric Commercial Vehicle

The traction motor of Hybrid Electric Commercial Vehicle(HECV) should have the characteristics such as high power versus weight ratio and very high torque at low speed. So interior permanent-magnet synchronous motor(IPMSM) is suitable for HECV. This paper presents a maximum torque per ampere(MTPA), a field weakening (FW) control and a reduced-order observer of IPMSM for HECV. By using computer simulation, we validate the effectiveness of the proposed system.

IPMSM Vector Control using an I/F Initial Operating Method

Owing to the few signals are generated using low resolution position sensor at low speed, rotor position estimation is difficult in drum washing machine application. Besides, inertia of water and drum makes the initial load to almost two times of rated load. Therefore over current can be occurred at initial operation and it can affect the control performance. In this paper, IPMSM vector control for drum washing machine is proposed by applying I/F initial operating method and sensorless control. And we verify the performance through experiment of drum washing machine.

A study on the line-interactive UPS using the series voltage compensator

This paper presents a three-phase line-interactive uninterruptible power supply (UPS) system with series-parallel active power-line conditioning capabilities, using synchronous reference frame (SRF) based controller, which allows an effective power factor correction, source harmonic voltage compensation, load harmonic current suppression and output voltage regulation. The three-phase UPS system consists of two active power compensator topologies. One is a series active compensator, which works as a voltage source in phase with the source voltage to have the sinusoidal source current and high power factor under the deviation and distortion of the source voltage. The other is a parallel active compensator, which works as a conventional sinusoidal voltage source in phase with the source voltage, providing to the load a regulated and sinusoidal voltage with low total harmonic distortion (THD). The control algorithm using SRF method and the active power flow through the line-interactive UPS systems are described and analytically studied. The simulation results are depicted in this paper to show the effect of the proposed algorithms.

New Power Conditioning System combined interleaved full-bridge converter with half-bridge inverter

This paper proposed a new PCS(Power Conditioning System) which is combined with interleaved full-bridge converter and half-bridge inverter. Standby power using battery power conditioning system(PCS) need isolation and high boost ratio dc-dc converter two interleaving full-bridge converters connect parallel input with series output, and its output have combined input of half bridge inverter with series connected capacitors. Halfbridge inverter has fewer switches than full bridge inverter. The performance is verified through simulation and experiment with 1.5kW PCS.