• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.1058-1065
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• 2015

This paper present a current predicting control method for PMSM (permanent magnet synchronous motor) to improve the tracking performance of stator current, which regards the current vector as the control target. Solving the model state equation in the static frame (α-β frame), the dynamic change of current vector will be gained as three independent terms. These change terms, which contain the prediction of current vector, are discretized and simplified by Taylor series expansion and used to get the voltage vector as the predictive control quantity. SVPWM will transform the control voltage to the switching signal of inverter, which is newly deduced for the current vector. Simulation and experiment results are given to testy and verify the performance of this method.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.2018-2020
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• 1998

In design of a digital current controller for a 3$\phi$ voltage-source (VS) PWM converter, its conventional model, i.e., stationary or synchronous reference frame model, is used in obtaining its discretized version. It introduces, however, inherent errors since the following practical problems are not taken into consideration: the characteristics of the space vector-based pulsewidth modulation (SVPWM) and the time delays in the process of sampling and computation. In this paper, the new hybrid reference frame model of the 3$\phi$ VS PWM converter is proposed considering these problems. In addition, the direct digital current controller based on this model is designed without any prediction or extrapolation algorithm to compensate the time delay. So the control algorithm is made very simple. The validity of the proposed algorithm is proved by the computer simulation results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.3
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• pp.651-659
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• 1999

This Paper Proposes new speed and electromagnetic torque control of an induction motor, which is robust against time varying parameters. The control is based on adaptive vector control with serial block adaptive algorithm. Motor parameters used to estimates slip frequency and electromagnetic torque. Parameters mismatch in the control system detrimentally affects slip frequency estimation and torque response. In order to compensate lot degradation of the responses, an adaptive identifier for the magnetizing inductance and the secondary time constant is introduced. adaptive vector control system consisted of two subsystems, a vector control system realized on synchronous frame and a parameter identification system on stationary frame. the effectiveness of the proposed method was verified by some digital simulations.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1081-1083
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• 2002

Voltage sag is discussed a important problem of power quality in transmission sys-tem. So recently The study on the compensatio-n for voltage sag is made good progress, Especially a compensation in unbalance sources system is difficult. In this paper, we proposed a series voltage compensator and a rejection of voltage ripple from synchronous frame in unbal-anced sources

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1140-1142
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• 2002

This paper is proposed to position and speed control of interior permanent magnet synchronous motor(IPMSM) drive without mechanical sensor. The rotor position, which is an essential component of any vector control schemes, is calculated through the instantaneous stator flux position and an estimated flux value of rotating reference frame. A closed-loop state observer is implemented to compute the speed feedback signal. The validity of the proposed sensorless scheme is confirmed by simulation and its dynamic performance is examined in detail.

• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.4
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• pp.333-341
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• 2013

In this paper, a feedback linearization control is proposed to regulate the output voltages of a three-phase four-wire inverter under the unbalanced and nonlinear load conditions. First, the nonlinear model of system including the output LC filters is derived in the d-q-0 synchronous reference frame. Then, the system is linearized by the multi-input multi-output feedback linearization. The tracking controllers for d-q-0-components of three-phase line-to-neutral load voltages are designed by linear control theory. The experimental results have shown that the proposed control method gives the good performance in response to the load conditions.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.44-45
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• 2013

본 논문은 3상 PMSM 동작 중 한 개의 상이 고장이 났을 경우, 2상을 통하여 고장허용 동작을 하는데 있어서 발생하는 토크 리플 저감 방법에 대하여 연구를 하였다. 기존의 방법들이 기본파 주파수로 회전하는 동기좌표계상에서 전향 보상 방식으로 교류 성분의 전류를 제어함으로써 토크 리플을 보상하는 데에 반해 제안한 방법은 기본파 주파수의 2배수로 회전하는 동기좌표계상에서 직류 성분의 전류로 토크 리플을 보상하기 때문에, 저속 운전뿐만 아니라 고속 운전시에도 그 보상 특성이 매우 우수하다. 제안한 방법은 자동차용 전동식 조향 시스템에 적용하여 그 유효성을 실험적으로 검증하였다.

• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.271-272
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• 2011

본 논문은 SOGI를 이용한 정상분 전압 검출을 기반으로 하는 SRF(synchronous reference frame)-PLL(phase locked loop) 시스템을 제안한다. 일반화된 2차 적분기의 이중으로 사용하여 QSG(Quadrature-signals generator)의 성능을 개선하여 전압 불평형, 고조파 왜곡 등으로 인한 오차 발생 시에도 빠르고 정확한 위상 검출이 가능하도록 하였으며 본 논문에서 제시한 알고리즘은 PSIM 프로그램 결과를 통하여 타당성을 입증한다.

• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.103-105
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• 2008

본 논문에서는 동기좌표계를 이용한 단상 계통연계형 태양광 인버터의 새로운 전류제어 기법을 제시한다. 기존의 정지좌표계 단상 인버터 전류제어 방법인 PI제어기와 PR제어기를 먼저 알아보고, 기존의 가상 2상 전류 생성기를 통해 단상 시스템을 동기좌표계 모델에 적용하는 전류제어기법을 기술한다. 그리고 가상 2상 전류 생성기의 새로운 방법을 제안한다. 제안된 전류 생성기는 지령 전류를 이용하여 새로운 전류를 생성하는 것으로 시스템의 안정도와 과도상태 응답특성을 개선하였다. 모의실험을 통해 기존의 방식과 제안된 방식을 비교함으로써 그 우수성을 입증한다.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.55 no.1
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• pp.21-25
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• 2006

This paper describes the novel control techniques design of VSC(Voltage Sag Corrector) for the purpose of power line quality enhancement. A fast detecting technique of voltage sag is implemented through the detection of instantaneous value on synchronous rotating do-reference frame. The first order digital filter is added in the detection algorithm to protect the insensitive characteristics against the noise. The relationship between the total detection time and cut-off frequency of the filter is described. The size of the capacitor bank used as the energy storage element is designed from the point of view of input/output energy with circuit analysis. Finally, the validity of the proposed scheme is proven through the simulated results.