• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.1
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• pp.80-83
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• 2022

This paper proposes an initial rotor polarity detection algorithm of a single-phase permanent magnet synchronous motor (SP-PMSM) related to stable open-loop starting for sensorless operation. Generally, the SP-PMSM needs an asymmetric air-gap structure to can avoid the initial starting failure at zero torque point. Therefore, the rotor polarity information can be obtained by using the DC offset current direction of a stator current through a high frequency voltage injection into an SP-PMSM with an asymmetric air gap. In this paper, the proposed rotor initial polarity detection algorithm is verified through several experimental results.

• Journal of IKEEE
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• v.23 no.3
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• pp.1020-1026
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• 2019

In this paper, a rotor polarity detection algorithm is proposed to control the single-phase permanent magnet synchronous motors(SP-PMSMs) for high speed sensorless operation. Generally, the sensorless control of a SP-PMSM is switched to the sensorless operation in a specific speed region after the open loop startup. As a result, it is necessary to detect the rotor polarity to maintain a constant rotational direction of the SP-PMSM at the starting process. There, this paper presents a novel rotor polarity detection method using a high frequency voltage signal and offset current which is generated by current regulator. The proposed algorithm verified the effectiveness and usefulness of the rotor polarity detection through several experiments.

• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1515-1527
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• 2018

This paper presents a sensorless speed control of IPMSM (Interior Permanent Magnet Synchronous Motor) using the high-frequency (HF) square wave injection method. In the proposed HF pulsating square wave injection method, injection voltage is applied into the estimated d-axis of rotor and high-frequency induced q-axis current is considered to estimate the rotor position. Conventional square wave injection methods may need complex demodulation process to find rotor position, while in the proposed method, an easy demodulation process based on the rising-falling edge of the injected voltage and carrier induced q-axis current is implemented, which needs less processing time and improves control bandwidth. Unlike some saliency-based sensorless methods, the proposed method uses maximum torque per ampere (MTPA) strategy, instead of zero d-axis command current strategy, to improve control performance. Furthermore, this paper directly uses resultant d-axis current to detect the magnet polarity and eliminates the need to add an extra pulse injection for magnet polarity detection. As experimental results show, the proposed method can quickly find initial rotor position and MTPA strategy helps to improve the control performance. The effectiveness of the proposed method and all theoretical concepts are verified by mathematical equations, simulation, and experimental tests.

• Journal of IKEEE
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• v.23 no.2
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• pp.622-627
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• 2019

This paper propose an initial rotor position detection method for sensorless operation of a single-phase permanent magnet synchronous motor(SP-PMSM) with asymmetric air-gap. In general, the sensorless control based on back-emf estimation is difficult to estimate the back-emf at the zero and low speed regions. For this reason, an open loop start-up technique is indispensable, and it is also necessary to detect the initial position of the rotor in order to rotate in a certain direction. In this paper, we propose a method to detect rotor polarity by adding offset voltage to high frequency voltage signal based on the magnetic characteristics of SP-PMSM. The validity and usefulness of the proposed algorithm are verified through several experimental results.

• Journal of IKEEE
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• v.24 no.4
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• pp.1004-1010
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• 2020

This paper proposes an initial rotor magnetic pole detection method for single-phase permanent magnet synchronous motors. The target motor cannot obtain position information based on the back emf in the low speed and stop state. Therefore, an open loop starting process is required, and in this process, initial rotor position information for low current and soft start is need. The proposed initial rotor magnetic pole detection algorithm considers the effect of asymmetric air- gap and magnetic flux. In addition, the high-frequency voltage signal injection and the offset voltage for accurate detection is used. As a result, the permanent magnet poles are is determined by acquiring the maximum value of the induced current using the virtual dq-axis.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.410-411
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• 2019

본 논문에서는 홀 센서를 사용하지 않고 단상 영구자석 동기 전동기의 초기 회전자 자극을 검출하여 안정적인 오픈루프 기동 및 센서리스 운전 기법을 제안한다. 제안한 회전자 초기 자극 검출 방법은 비대칭 공극을 갖는 단상 영구자석 동기 전동기에 고주파 전압을 인가한 후 회전자 초기 극성에 따른 자기회로의 비 포화 및 포화여부를 저역통과필터를 이용하여 빠르게 검출하는 방법을 제안하였다. 제안된 초기 자극 검출 방법은 다수의 실험 결과를 통해 안정적 기동 및 센서리스 운전이 가능함을 입증하였다.