• Journal of Magnetics
• /
• 제20권2호
• /
• pp.166-175
• /
• 2015

In this study, we describe the design method of a Brush-less DC (BLDC) motor with delta winding connection. After designing delta winding connection model with the $60^{\circ}$ flat-top region of the Back Electro-Motive Force (BEMF), an ideal current source analysis and a voltage source analysis, with a 6-step control, were conducted primarily employing Finite Element Method. In addition, as a current controller, we considered the Current Regulator with PI controller using Simulink for the comparison of torque characteristics. When the input current is controlled, the switching regions and reference signals are determined by means of the phase BEMF zero-crossing point. In reality, the input current variation depends on the inductance as well as input voltage, and it causes a torque ripple after all. Therefore, each control method considered in this research showed different torque ripple results. Based on the comparison, the causes of the torque ripple have been verified in detail.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제48권6호
• /
• pp.336-341
• /
• 1999

In this paper a control method to compensate the fluctuation in source voltage by using reactive current is presented. When the source voltage is changed within $\pm$10[%] range, the unit power factor is carried out. Otherwise, the converter is controlled by variable power factor. By using above control, the converter input voltage is maintained constantly. And then it was certified by simulation with the ACSL and several experiments.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2008년도 하계학술대회 논문집
• /
• pp.271-273
• /
• 2008

A novel white-LED (light emitting diode) backlight system for 46"LCD TVs which involves the average current controlled X-Y channel driving method is proposed, which is composed of 1 converter and row and column channel switches. In the conventional X-Y channel driving driven with a constant voltage source, the driving current of LED increases because the threshold voltage of LED decreases when LED temperature goes up. To maintain the luminance of backlight constant, the average current controlled X-Y channel driving will be employed. Finally the results are confirmed by experimental results.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
• /
• pp.367-370
• /
• 1987

A high-performance PWM technique in current-controlled AC to DC converter is introduced. This converter used information about source voltage vectors to make good PWM switching pattern that it can control the DC output voltage with reduced ripple factor and rapid response. In addition to reduction of harmonic current, AC input power factor can be controlled to leading or lagging by current reference. Simulation was made based on analytical approach and it showed a good agreement with theory.

• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 2008년도 추계학술대회 논문집
• /
• pp.307-310
• /
• 2008

This paper is proposed the vector control of 3-phase induction motor drive system by photovoltaic generation. For performance of vector control using a current control voltage source inverter(CC-VSI). CC-VSI is controlled by torque and flux producing component of motor current, relating with current and voltage value of photovoltaic arrays at maximum power point that varies follow different level of insolation. The MPPT using a DC-DC converter controlled the duty cycle to track maximum power from PV under different insolation conditions. The simulation results are shown that the characteristics and performance of drive system, which varies as each conditions of light by expresses in voltage($V_{dq}$), current($I_{dq}$), speed of motor and torque.

• 조명전기설비학회논문지
• /
• 제20권8호
• /
• pp.88-95
• /
• 2006

본 논문은 분산전원의 주파수 변동에 적응하는 아날로그형의 능동 전력 필터를 제안하였다. 주파수 변동이 심한 분산전원에서 비선형부하에 의해 발생한 고조파의 제거를 위해 전원의 고조파 전류와 주파수가 같고 위상차가 $180[^{\circ}]$인 보상 전류를 투입함으로써 전원의 고조파를 제거하였다. 이때 보상전류의 생성을 위한 기준전류 검출회로는 변동하는 전원 주파수를 추적하고 적응하도록 PLL과 VCGIC(Voltage Controlled Generalized Impedance Converter)를 사용하였다. 시뮬레이션과 실험을 통해 제안된 시스템이 주파수가 변동하는 분산전원의 고조파 전류를 효과적으로 제거함을 증명하였다.

• Journal of Electrical Engineering and Technology
• /
• 제10권1호
• /
• pp.8-17
• /
• 2015

This paper analyses the power flow of a three-feeder/multi-bus distribution system by a custom Generalized Power Quality Conditioner (GUPQC). The GUPQC has been realized by three voltage source converters (VSCs) coupled back-to-back through a common DC-link capacitor on the DC-side. One feeder was controlled by the shunt compensator, whereas each of the other two feeders was controlled by the proposed novel series compensator. The GUPQC has the capability to simultaneously compensate voltage and current quality problems of a multi-bus/three-feeder distribution system. Besides that, the power can be transferred from one feeder to other feeders to compensate for poor power quality problems. Extensive simulation studies were carried out by using MATLAB/SIMULINK software to establish the ability of the GUPQC to improve power quality of the distribution systems under distorted supply voltage conditions.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2006년도 하계종합학술대회
• /
• pp.519-520
• /
• 2006

In this paper, we propose a voltage-controlled ring oscillator (VCO) for a 900 MHz low-noise fractional-N frequency synthesizer. The VCO delay cell is based on an nMOS source-coupled pair with load elements [1] and a combined tail current sources which consist of a large and a small current source to control the integer and fractional behaviors, respectively. The Spectre simulation results of the scheme in a 0.18um CMOS process show the accurate control of the KVCO better than the conventional one.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1996년도 하계학술대회 논문집 A
• /
• pp.328-332
• /
• 1996

Current controlled inverter is the device which gives fast and accurate current output response for current command Existing current controlled inverters have no way but to take a narrow bandwidth due to resonance of output filter. In this paper, High performance current controlled inverter with multiloop structure is designed and modeling is executed in that basis. This paper realizes the high performance current controlled inverter with the bandwidth above resonant frequency, controls proposed inverter by analog controller, analyzes the performances through simulation and tests 2kW prototype system.

• 전자공학회논문지B
• /
• 제28B권12호
• /
• pp.38-50
• /
• 1991

A current-controlled scheme of pulse width modulation voltage source inverter (PWM VSI) has attracted considerable attention due to its fast response with current limit and especially suitable for potentially high performance applications such as AC motor drives and UPS systems. These features yield near-sinusoidal currents in the load with reduced current peaks, lower inverter switching frequency and reduce inverter and load stresses. A high performance current-controlled inverter must have a quick response in transient state and low harmonic current in steady state. This paper compares and shows the controlled-characteristics with hysteresis controller(HC), ramp comparison controller(RCC) and predictive controller(PC) of PWM inverter to control actual current of VSI-IM.