• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.3
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• pp.519-523
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• 2007

In this paper, we propose a precise parameter extraction of interior permanent magnet (IPM) motors based on finite element analysis. For the calculation of the two-axis inductances Ld and Lq, the slotting effect and cross magnetization due to torque angle are considered. It is examined that back electro-motive force (BEMF) constant is affected by the magnetic saturation in different ways dependent on motor types. Numerical analyses and some measurements are performed for a spoke type and a flux barrier type IPM motors

• Journal of the Korean Society for Precision Engineering
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• v.15 no.8
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• pp.183-192
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• 1998

In this paper, we measure the back-EMF and the thrust of a linear brushless DC motor along the relative position between coils and magnets in various speed environments in order to obtain the back-EMF and the thrust as a function of a motor position. The measured back-EMF function and thrust function of the position differ from the analytical ones within 5%. The measured back-EMF and thrust function can, then, be employed in controlling the thrust ripple of the linear motor. Furthermore, to minimize the torque ripple of the linear motor, we suggest the design method to shape the back-EMF and thrust function of the linear motor.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.8-15
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• 2019

The PM synchronous motor drives with vector control have been applied to wide fields of industry applications due to its high efficiency. The rotor position information for vector control of a PM synchronous motor is detected from the rotor position sensors or rotor position estimators. The sensorless control based on the mathematical model of PM synchronous motor is generally used and it can be classified into back EMF -based sensorless control and magnet flux-based sensorless control. The rotor position estimating performance of the back EMF-based sensorless control is deteriorated at low speeds since the magnitude of back EMF is proportional to the motor speed. The magnitude of the magnet flux for estimating rotor position in the flux-based sensorless control is independent on the motor speed so that the estimating performance is excellent for wide speed ranges. However, the estimation performance of the model-based sensorless control may be influenced by the motor parameter variation since the rotor position estimator uses the mathematical model of the PM synchronous motor. In this paper, the rotor position estimation performance for the back EMF based- and flux-based sensorless controls is analyzed theoretically and is compared through the simulation and experiment when the motor parameters including stator resistance and inductance are varied.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.400-401
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• 2019

본 논문에서는 전동기 제정수와 전압 및 전류제한 값에 따른 단상 영구자석 동기전동기의 능력곡선을 분석하였다. 역기전력 상수와 고정자 인덕턴스 및 전압 전류 제한값에 따라 영구자석 동기전동기의 능력곡선이 변하게 되며, 최대토크를 얻을 수 있는 인가전압의 크기 및 위상이 결정된다. 제안한 능력곡선의 분석방법을 통하여 얻은 최대토크에서의 인가전압을 컴퓨터 모의실험으로 검증하였다.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.647-648
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• 2015

최근 최저효율제를 대비한 프리미엄급 고효율 전동기의 필요성이 대두됨에 따라 유도전동기를 대체할 수 있는 고효율 전동기로써 영구자석 매입형 동기 릴럭턴스 모터(PMA-SynRM)가 각광받고 있다. 하지만 모터의 속도와 토크를 제어하기 위해 회전자 속도와 위치 정보를 측정할 수 있는 센서가 필요하고, 이 때 센서 설치의 공간적 문제, 센서의 유지/보수 및 시스템의 추가 비용 발생 등 많은 문제점들이 발생한다. 따라서 센서를 제거하기 위한 센서리스 위치 및 속도 제어에 관한 연구가 폭 넓게 진행되고 있다. 하지만 모터를 운전함에 따라 저항이나 역기전력 상수, 인덕턴스 등의 제정수의 변동이 발생하게 되고 센서리스 제어 시 이러한 변동에 의해서 추정 속도 및 위치에 오차가 발생하게 된다. 본 논문에서는 이러한 오차의 보상을 위해 MRAS(Model Reference Adaptive System) 방식을 적용한 센서리스 제어를 제안한다.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.529-530
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• 2016

직류 전동기는 연속적으로 회전하기 위해서 브러시와 정류자로 이루어진 기계적인 정류 회로를 가진다. 회전자의 위치에 따라 브러시와 정류자의 접촉 구조가 변하고 직류 전동기의 등가 회로 또한 달라진다. 이러한 구조적 문제점 때문에 직류 전동기의 저항, 인덕턴스, 역기전력 상수와 같은 파라미터가 변화하고 전동기가 회전하면서 전기자 전류에 맥동이 발생한다. 본 논문에서는 기계적인 정류 회로를 고려한 직류전동기를 모델링하고 분석하였다. 그리고 브러시와 정류자에 의한 전기자 전류의 맥동이 위치 제어의 응답 특성에 어떤 영향을 미치는지 시뮬레이션을 통해 확인하였다.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.6
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• pp.602-609
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• 2011

This paper proposes a simple initial rotor position estimation method to obtain a stable startup performance for back EMF-based sensorless control. The proposed estimation method is achieved at standstill by using the current response to difference between each of the stator winding inductance. This initial rotor position estimation method can be easily implemented to control algorithm without any other external devices. The proposed algorithm is also not affected by motor parameter. The validity of the proposed method is demonstrated by experimental result.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.1
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• pp.82-88
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• 2009

Low costed position sensor or sensorless control method is generally used in the motor control for home appliance because of the material cost and manufacture standard restriction. In conventional sensorless method, the stator resistance and back-EMF coefficient are varied by the motor speed and load torque variation. Therefore, position error occurred when the motor is operated by sensorless control method because of these variations. In this paper, the compensation method is proposed for sensorless position error using 2 hall sensors.

• Journal of Auto-vehicle Safety Association
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• v.16 no.2
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• pp.51-59
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• 2024

This study presents a method for health monitoring of rotating objects for mobility based on multiple recursive least squares(RLS) algorithms. The performance degradation of the rotating objects causes low handing / low driving performances and even fatal accidents. Therefore, health monitoring algorithm of rotating objects is one of the important technologies for mobility fail-safe and maintenance areas. In order for health monitoring of rotating objects, four recursive least squares algorithms with forgetting factor were designed in this study. The health monitoring algorithm proposed in this study consists of two steps such as uncertainty estimation and parameter changes estimation. In order to improve estimation accuracy, time delay function was applied to the estimated signals based on the first order differential equation and forgetting factors used for the RLS were reasonably tuned. The health monitoring algorithm was constructed in Matlab/Simulink environment and simulation-based performance evaluation was conducted using DC motor model. The evaluation results showed that the proposed algorithm estimates the actual parameter differences reasonably using velocity and current information.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.4
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• pp.291-299
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• 2007

To operate a permanent magnet synchronous motor (PMSM) at a maximum torque per ampere (MTPA) operation point, the exact values of machine parameters such as inductances and back-EMF constant, which are sensitive to motor phase currents and temperature respectively, should be blown. An adaptive estimation method for on-line estimation of the machine parameters is not suitable for practical applications since it has difficulties in estimating exact values and requires complex mathematical calculations. The purpose of this paper is to present a simple MTPA operation point tracking control strategy for vector controlled PMSM drives with slow dynamic loads. The proposed method searches MTPA operation points by modulating current phase angle and observing the variation in command power. The current angle modulation strategy is designed to sense the effect of load variations in the command power. Therefore, the proposed method can track the MTPA operation points of the PMSM regardless of load variations. Computer simulation and experimental study is also presented to show the effectiveness of the proposed method.