• Journal of international Conference on Electrical Machines and Systems
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• 제3권2호
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• pp.169-175
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• 2014

This paper presents an improved direct power control (DPC) strategy for grid-connected voltage source inverter (VSI) under unbalanced and harmonic grid voltage conditions. Based on the mathematic model of VSI with the negative sequence, 5th and 7th harmonic voltage components consideration, a PI controller is used in the proposed DPC strategy to achieve the average output power regulation. Furthermore, vector PI controller with the resonant frequency tuned at the two times and six times grid fundamental frequency is adopted to regulate both negative and harmonic components, and then two alternative targets of the balanced/sinusoidal current and smooth active/reactive output power can be achieved. Finally, simulation results based on MATLAB validate the availability of the proposed DPC strategy.

• 한국산학기술학회논문지
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• 제12권3호
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• pp.1289-1301
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• 2011

본 논문에서는 전 속도 영역에서 안정적인 자속추정이 가능한 유도전동기 자속추정방법을 제안 하였다. 제안된 방법은 전압, 전류, 속도 등의 정보를 통하여 자속각을 연산하는 유도전동기 직접벡터제어방식을 이용하였다. 유도전동기 벡터제어에 있어서 자속정보는 필수적이기 때문에 정확한 자속을 추정하기 위한 방법으로 저속영역에서 는 전류모델 자속 추정기를, 고속영역에서는 전압모델 자속 추정기를 각각 이용함으로써 전 속도영역에서 정확한 자속을 추정할 수 있었다. 또한 기본적인 속도, 전류, 자속제어기는 PI제어기를 이용하였으며, 각각의 적분에 의한 오차를 보상하기 위하여 Anti-windup PI 제어기를 추가하였다. 제시한 제어기의 타당성을 알아보고자 Matlab / simulink를 이용하여 전류모델, 전압모델 자속 추정기를 설계하여 정확한 자속추정이 이루어짐을 확인하였으며, 유도 전동기 벡터제어 시 간접벡터와 직접벡터방식의 파라미터 영향에 따른 분석을 통해 보다 정밀한 제어가 이루어짐을 확인하였다. 이와 같은 시뮬레이션 결과를 분석 하여 제시한 알고리즘의 타당성을 입증하였다.

• 전력전자학회논문지
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• 제10권6호
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• pp.534-542
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• 2005

본 논문은 퍼지제어기를 이용한 엘리베이터용 표면 부착형 영구자석 동기전동기의 벡터제어기법에 관하여 기술한다. PI제어기를 속도제어기로 사용하는 기존의 엘리베이터 시스템은 기계적 공진 때문에 게인값을 높은 값으로 선정하지 못하여 시스템의 성능이 떨어지는 단점이 있다. 이러한 점을 보완하기 위해 속도제어기에 가속도 피드백 루프를 추가하는 방법이 제안되었지만, 제어기의 구현을 위해 파라미터 정보가 필요하다는 단점을 가지고 있다. 본 논문에서는 속도제어기에 기존의 PI제어기 대신 퍼지제어기를 적용하여 벡터제어기법을 구현하였다. 퍼지제어기의 성능을 검증하기 위해 무부하 및 부하조건에서 시뮬레이션과 실험을 실시하여 PI제어기와 비교하였다.

• 전기학회논문지P
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• 제51권3호
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• pp.111-119
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• 2002

This paper proposes a speed control system based on a fuzzy logic approach, integrated with a simple and effective adaptive algorithms. And this paper attempts to provide a thorough comparative insight into the behavior of induction motor drive with PI, direct and improved fuzzy speed controller. A indirect vector controlled induction motor is simulated under varying operating condition. The validity of the comparative results is confirmed by simulation results for induction motor drive system.

• 전자공학회논문지B
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• 제30B권11호
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• pp.93-101
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• 1993

The transfer function of vector-controlled induction motor is represented along with both unstructured and structured uncertainty such as the error of rotor time constant and current ripple. The low-pass-filter behavior of a magnetizing inductance gets rid of unstructured uncertainty in the transfer function. The robust controller to compensate variation of the transfer function is designed using simple P-I linear controllers. The coefficients of speed PI controller are determined from an overshoot and a rising time of system and the coefficients of model-following PI controller are obtained using the solution of Riccati equation of LQR control in the state space equation of the error system. Experimental results with the DSP-based model-following robust controller are shown a good robustness against the structured uncertainty of the motor.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권11호
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• pp.664-670
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• 2004

This paper presents a new velocity estimation strategy of a non-salient permanent magnet synchronous motor (PMSM) drive without high frequency signal injection or special PWM pattern. This approach is based on the d-axis current regulator output voltage of the drive system that has the information of rotor position error. The rotor velocity can be estimated through a rotor position tracking PI controller that controls the position error to zero. For zero and low speed operation, PI controller gains of rotor position tracking controller have a variable structure according to the estimated rotor velocity. In order to boost the bandwidth of PI controller around zero speed, a loop recovery technique is applied to the control system. The proposed method only requires the flux linkage of permanent magnet and is insensitive to the parameter estimation error and variation. The designers can easily determine the possible operating range with a desired bandwidth and perform the vector control even at low speeds. The experimental results show the satisfactory operation of the proposed sensorless algorithm under rated load conditions.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1997년도 전력전자학술대회 논문집
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• pp.357-363
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• 1997

The windup phenomenon appears and results in the performance degradation when the PI controller output is saturated. A new anti-windup PI controller is proposed to improve the control performance of the variable-speed motor drives and it is experimentally applied to the speed control of a vector-controlled induction motor driven by a pulse width modulated(PWM) voltage source inverter (VSI). The integral state is separately controlled corresponding to whether the PI controller output is saturated or not. The experimental results show that the speed response has the much improved performances such as small overshoot and fast settling time over the conventional anti-windup technique. Although the operating speed command is changed, the similar control performance can be obtained by using the PI gains selected in the linear region.

• 대한전기학회논문지
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• 제43권7호
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• pp.1112-1120
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• 1994

This paper presents a servo control scheme for the surface-mounted permanent-magnet synchronous motor(SPMSM) which essentially uses vector control algorithm. The control system is composed of the PI controller for speed control and the current controller using space voltage vector PWM technique. The high-speed calculation and processing for vector control is carried out by TMS320C31 digital signal processor and IGBT module. The proposed scheme is verified through digital simulations and experiments for 2.2kW SPMSM and shows good dynamic performance.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 춘계학술대회 논문집
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• pp.420-423
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• 2009

The conventional fixed gain PI controller is very sensitive to step change of command speed, parameter variation and load disturbances. The precise speed control of interior permanent magnet synchronous motor(IPMSM) drive becomes a complex issue due to nonlinear coupling among its winding currents and the rotor speed as well as the nonlinear electromagnetic developed torque. Therefore, there exists a need to tune the PI controller parameters on-line to ensure optimum drive performance over a wide range of operating conditions. This paper is proposed hybrid intelligent-PI(HIPI) controller of IPMSM drive using adaptive learning mechanism(ALM) and fuzzy neural network(FNN). The proposed controller is developed to ensure accurate speed control of IPMSM drive under system disturbances and estimation of speed using artificial neural network(ANN) controller. The PI controller parameters are optimized by ALM-FNN at all possible operating condition in a closed loop vector control scheme. The validity of the proposed controller is verified by results at different dynamic operating conditions.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 춘계학술대회 논문집 에너지변화시스템부문
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• pp.225-227
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• 2009

The conventional fixed gain PI controller is very sensitive to step change of command speed, parameter variation and load disturbances. The precise speed control of interior permanent magnet synchronous motor(IPMSM) drive becomes a complex issue due to nonlinear coupling among its winding currents and the rotor speed as well as the nonlinear electromagnetic developed torque. Therefore, there exists a need to tune the PI controller parameters on-line to ensure optimum drive performance over a wide range of operating conditions. This paper is proposed artificial intelligent-PI(AIPI) controller of IPMSM drive using adaptive learning mechanism(ALM) and fuzzy neural network(FNN). The proposed controller is developed to ensure accurate speed control of IPMSM drive under system disturbances and estimation of speed using artificial neural network(ANN) controller. The PI controller parameters are optimized by ALM-FNN at all possible operating condition in a closed loop vector control scheme. The validity of the proposed controller is verified by results at different dynamic operating conditions.