• Journal of Electrical Engineering and Technology
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• 제12권1호
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• pp.100-109
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• 2017

This paper proposes performance improvement schemes for sensorless PMSM control drive using a four-switch three-phase inverter (so-called B4 inverter). In the proposed scheme, the back-EMF estimation-based sensorless control algorithm is used to control the brushless PMSM without position sensors. In order to have stable operation, this paper presents a gain adjustment scheme that compensates the reduction of stable sensorless operation range as long as the rotor speed increases. In B4 topology, the center point of dc-link capacitors is connected to 3-phase load, and it is prone to have the load current distortion. Hence, to mitigate this problem, a distortion compensation scheme by modifying voltage commands using measured dc-link potentials is proposed in this paper. The validity of the proposed method is evaluated by simulations and experiments.

• 전기학회논문지P
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• 제60권4호
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• pp.227-235
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• 2011

This paper describes a PMSM control algorithm for realizing a low-cost motor drive system using a general purpose microcontroller. The proposed sensorless algorithm consists of the current observer and the sensorless scheme based on instantaneous reactive power. Also the control board system is not the high-cost DSP(digital signal processor) system but the general purpose microcontroller and it allows to reduce the unit cost of the motor system. However the clock frequency of the proposed microcontroller is one-fifths for the clock frequency of the DSP. In addition, the switching frequency must be selected as the lower frequency because of complex mathematic modeling of the sensorless algorithm. the low switching frequency augments the noise of the motor and might make accurate speed control impossible. Thus this paper proposes the optimization method to supplement the drawback of the general purpose microcontroller and the usefulness of the proposed method is verified through the experiment.

• 조명전기설비학회논문지
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• 제25권12호
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• pp.82-87
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• 2011

In this paper, a sensorless speed control system is designed for the next generation high speed railway at zero and low speed region. The applied vector control scheme is a maximum torque per ampere(MTPA) method to utilize reluctance torque of IPMSM. The designed sensorless control scheme is a rotating high frequency voltage signal injection method. To verify the designed system, a simulator for the vector controller and sensorless controller is implemented using Matlab/simulink.

• 전력전자학회논문지
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• 제5권6호
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• pp.552-559
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• 2000

유도전동기의 센서리스 벡터제어 방식은 선동기 등가모델을 이용하는 경우가 대부분이다. 따라서 센서리스 벡터 제어 기능을 갖는 인버터에 전동기 상수의 자동 측정 가능은 필수적이며, 전동기 상수 측정의 정밀도가 센서리스 벡터제어 인버터의 성능에 큰 영향을 미친다. 본 논문에서는 기존의 자동 측정 방법에 있어서의 문제점을 고찰하고, 이를 보완한 새로운 유도전동기 상수 측정 방법을 제시한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 추계학술대회 논문집
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• pp.119-122
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• 2003

This paper describes the sensorless technique for the surface-mounted permanent-magent synchronous motor(SPMSM or PMSM) drive based on magnetic saliency. The control technique is a sensorless control algorithm that injects the high frequency voltage to the stator terminal in order to estimate the rotor position and speed. The rotor position and speed for sensorless vector control is achieved by appropriate signal processing to extract the position information from the stator current in the low speed range including zero speed. Proposed sensorless algorithm using the double-band hysteresis controller and initial rotor position detection exhibits excellent reference tracking and increased robustness. Experimental results are presented to verify the feasibility of the proposed control schemes.

• 조명전기설비학회논문지
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• 제22권3호
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• pp.66-73
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• 2008

This paper presents a position sensorless control system of SRM over wide speed range. Due to the doubly salient structure of the SRM, the phase inductance varies along with the rotor position. Most of the sensorless control techniques are based on the fact that the magnetic status of the SRM is a function of the angular rotor position. The rotor position estimation of the SRM is somewhat difficult because of its highly nonlinear magnetizing characteristics. In order to estimate more accurate rotor position over wide speed range, Neural Network is used for this highly nonlinear function approximation. Magnetizing data patterns of the prototype 1-hp SRM are obtained from locked rotor test, and used for the Neural Network training data set. Through measurement of the flux-linkage and phase currents, rotor position is able to estimate from current-flux-rotor position lookup table which is constructed from trained Neural Network. Experimental results for a 1-hp SRM over 16:1 speed range are presented for the verification of the proposed sensorless control algorithm.

• Journal of Power Electronics
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• 제11권6호
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• pp.864-869
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• 2011

This paper presents a sensorless control and parameter estimation strategies for a Transverse Flux Rotating Motor (TFRM). The proposed sensorless control method is based on a Model Reference Adaptive System (MRAS) to estimate the stator flux. Parameter estimation theory is also applied into the sensorless control method to estimate motor parameters, such as inductances. The effectiveness of the proposed methods is verified by some simulations and experiments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 A
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• pp.12-14
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• 1998

Sensorless PMSM is much studied for the industrial applications and home appliances because a mechanical sensor reduces reliability and increases cost. This paper studies the stability of sensorless speed control of PMSM using state observer. Sensorless control scheme using state observer is known as a scheme having a comparatively good performance. Several papers have studied the stability of state observer control scheme, but have not considered parameter variation which is important to sensorless control. This paper studies the stability through computer simulation in case of parameter variation.

• 한국산업융합학회 논문집
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• 제21권6호
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• pp.439-444
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• 2018

The performance improvement in the high speed region for the sensorless based synchronous machine drive is discussed in the paper. Conventional dynamic overmodulation method in the vector controlled AC driver requires some calculation of maximum amplitude of the applying voltage vector to limit its amplitude, which leads to increase the calculation time of microprocessor. For low performance microprocessor, this might be impossible to complete the control loop within limited control time. Thus, to reduce the calculation time, the constantly limited amplitude for applying voltage vector is tried in this paper to drive sensorless based synchronous motor. Certainly, there exists some errors in amplitude and phase angle between inverter voltage and calculating voltage in the sensorless algorithm. But, this errors are too small to prevent the high speed sensorless operation within overmodulation region. The validities of the proposed method is proved by the experimental results.

• Journal of Power Electronics
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• 제12권1호
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• pp.75-82
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• 2012

Elimination of rotor position sensors mechanically coupled with the rotor shaft is attractive to variable speed drives primarily due to increased system reliability and cost reduction. In this regard, search for a simple and robust position sensorless control has been intensified in past few years specifically for low-cost, high-volume applications such as home appliances. This paper describes a new parameter insensitive position sensorless control for switched reluctance motor (SRM) drives satisfying such a need in this market segment. Two consecutive switch-on times of the controllable switch in hysteresis current control are compared to estimate the rotor position and speed. The proposed sensorless control algorithm is very simple to implement since it does not depend on extensive computation or any additional hardware. In addition, the proposed method is robust in that its dynamic performance is least affected by system parameter variations. The proposed approach is demonstrated on a single-controllable-switch-converter-driven SRM with two-phases that lends itself to a system with low cost and compact packaging which comes close to the intended applications. Analysis and simulation results followed by experimental verification are presented to demonstrate the feasibility of the proposed sensorless control method.