• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2005년도 춘계학술대회논문집
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• pp.449-454
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• 2005

Brushless DC Motor(PM BLDCM) is widely used in industrial applications due to its high efficiency and power density. In order to increase reliability and reduce system cost, this paper studies particularly applicable method for sensorless PM BLDCM drive system. The resulting third harmonic signal keeps a constant phase relationship with the rotor flux for any motor speed and load condition, and is practically free of noise that can be introduced by the inverter switching, making this a robust sensing method. As a result, the method described here is not sensitive to filtering delays, allowing the motor to achieve a good performance over a wide speed range. In addition, a simple starting method and a speed estimation approach are also proposed.

• 조명전기설비학회논문지
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• 제20권1호
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• pp.48-56
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• 2006

본 논문에서는 고정자의 3고조파 전압 성분을 이용하여 브러시리스 직류 전동기의 회전자 위치를 간접 검출하는 방법을 제안하였다. 3고조파 전압 성분은 회전자의 위치 정보를 가지고 있고 이 전압을 이용하여 정류 신호를 만들어 낼 수 있다. 따라서 정류 신호를 이용한 브러시리스 직류 전동기를 센서리스로 운전하는 방식은 역기전력 파형과 상전류가 비교적 정확한 동기를 유지할 수 있으므로 넓은 속도 범위에서 안정적인 센서리스 운전이 가능하다. 또한 정밀 속도 제어를 위해 PLL 회로를 적용함으로써 저속도에서도 높은 분해능을 얻을 수 있다. 따라서 기존에 속도 제어를 위해 필요했던 고가의 속도 센서인 레졸버와 엔코더 역할을 대체하여 전체적인 구동 회로의 가격을 낮출 수 있다.

• 한국태양에너지학회 논문집
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• 제29권5호
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• pp.65-72
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• 2009

The new method is proposed to improve high speed detection of grid voltage phase and magnitude during a voltage dip due to a grid faults. Usually, A LPF(Low Pass Filter) is used in the feedback loop of PLL (Phase Locked Loop) system because the measured grid voltage contains harmonic distortions and sensor noises. so, a new design method of the loop gain of the PI -type controller in the PLL system is proposed with the consideration of the dynamics of the LPF. As a result, a better transient response can be obtained with the proposed design method. The LPF frequency and PI controller gain are designed in coordination according to the steady state and dynamic performance requirement. This paper shows the feasibility and the usefulness of the proposed methods through the computer simulation and the lab-scale experiments.

• 조명전기설비학회논문지
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• 제23권2호
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• pp.108-114
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• 2009

데드존이나 비선형성이 존재하는 자동화 시스템의 고속 정밀제어를 위하여 새로운 하이브리드 적응제어 기를 제안한다. 제안된 시스템은 제어영역을 고속제어 영역과 정밀제어 영역으로 구분하여 제어한다. 먼저 퍼지 제어방식을 이용하여 고속제어를 수행하고, 오차가 설정된 범위 안에 진입하면 지터를 저감시킨 PFD를 이용한 PLL 제어기를 사용하여 정밀제어를 수행한다. 제안된 PFD는 데드존을 발생시키지 않아 지터 잡음과 응답특성을 개선하였다. 이론과 실험적인 연구가 수행되었고, 그 결과는 자동화 시스템의 제어 성능이 개선되었음을 입증한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.146-148
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• 1997

This paper investigates the position sensorless control of switched reluctance motor. The system consists of the position detection circuit by the new phase detection algorithm, digital logic commutator, PLL for speed control and 4-phase inverter. The performances in the proposed system are verified through the experiment.

• 전기의세계
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• 제30권11호
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• pp.717-727
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• 1981

The phase-locked loop technique developed in the 1930's has many advantages when applied to speed control. The speed control and analysis of a three phase induction motor using the PLL are described in this paper. In this system, the phase frequency detector (PFD) compares the actual motor speed from the pulses received from a shaft encoder and desired speed, and the difference adjusts the frequency of the inverter that feeds the motor, and excellent speed regulation in the order of 0.035(%) has been-obtained. A linear continuous model of the drive is developed and system response is analysed using conventional root locus techniques. Various compensating filters and feedback signals are considered and the need for addition of derivative feedback is shown. A sampled data model is used to study the effects of discrete PFD output. Stability limitson speed are predicted. A drive was implimented and experimental results are presented to verify theoretical predictions.

• Journal of Electrical Engineering and Technology
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• 제7권6호
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• pp.898-904
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• 2012

This paper presents a ride-through skill of PMSG wind turbine system under the distorted and unbalanced grid voltage dips. When voltage dips occur in the grid, pitch control and generator speed control as well as a parallel resistor of DC-link help to keep the turbine's safety. Modern grid code requires a wind turbine to supply reactive currents to help voltage recovery after grid faults clearance. In order to supply reactive currents to the grid in case of the distortedly unbalanced grid voltage dips, a special PLL is needed to control the grid side converter and to regulate the grid voltages symmetrically. The proposed method is applied to 2MW multi-pole PMSG wind turbine system, and verified by simulation.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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• pp.665-669
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• 2004

Generally, Slotless PM BLDC drive system is necessary that the three Hall-ICs evenly be distributed around the stator circumference and encoder be installed in case of the 3 phase motor. So, the Hall-ICs are set up in this motor to detect the main flux from the rotor, and the output signal from Hall-ICs is used to drive a power transistor to control the winding current. However, instead of using three Hall-ICs and encoder, we used only two Hall-ICs for the permanent magnet rotor position and for the speed feedback signals, and also for a microcontroller of 16-bit type (80C196KC) with the 3 phase Slotless PM BLDC whose six stator and two rotor designed. Two Hall-IC Hc and $H_B$ are placed on the endplate at 120 degree intervals, and with these elements, we can estimate information of the others phase in sequence through a rotating rotor.

• 반도체디스플레이기술학회지
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• 제14권3호
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• pp.45-50
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• 2015

This paper suggests the sensor-less speed control of PMSM (Permanent Magnet Synchronous Motor) without the position sensor of oil-free air compressor. It estimated d and q axis back electro motive force using Back-EMF (Electro motive Force) observer to control sensor-less speed of PMSM. Also it used the method that tracks the information of rotor position and speed using PLL (Phase Locked Loop) based on estimated d and q axis Back-EMF. The sensor-less speed control of PMSM for oil air compressor application is carried out with the introduced rotor position and speed tracking method. In this paper, the experimental characterization of the sensor-less drive is provided to verify the accuracy of the estimated position and the performance of sensor-less control is analyzed by results obtained from the experiment. Moreover, the potential of PMSM sensor-less drive in industrial application such as compressor drive is also examined.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 하계학술대회 논문집
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• pp.332-335
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• 1990

A digital phase-locked loop speed control system of a self-controlled permanent magnet synchronous mortar fed by a voltage source inverter is presented. This paper discribes the hardware and software design of the system. Variable speed control system for self-controlled permanent magnet synchronous motor is proposed. Simulation results demonstrate the validity of proposed methods. This proposed control technique is implemented by using a microprocessor-based system.