• 전력전자학회논문지
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• 제26권4호
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• pp.256-262
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• 2021

Six-phase motors can be used in industrial applications, such as an electric vehicle, due to their high reliability and low current magnitude per phase. An asymmetrical PMSM with two sets of three-phase windings is a commonly used structure for six-phase motors, with each winding set demonstrating a phase difference of 30°. Although the asymmetrical PMSM presents low torque ripples, its dynamic torque response deteriorates due to coupled components in the two three-phase windings. The decoupled VSD control is applied to eliminate the coupling effect. Load ratio control of two inverters for the six-phase PMSM is proposed in this study. DQ currents are controlled on the basis of two synchronous reference frames, and the six-phase drive system can be changed to a three-phase drive system when one inverter presents fault conditions. The operation and effectiveness of the proposed algorithm is verified through simulation and experiments. The six-phase drive system is transferred to a three-phase drive system by changing the current reference of the second DQ reference frame. Moreover, control of both torque and speed exhibits satisfactory performance before and after the mode change.

• 전기전자학회논문지
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• 제26권2호
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• pp.265-270
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• 2022

본 논문에서는 정지 좌표계 dq-축 전류를 기반으로 하는 비대칭 6상 PMSM의 스위치 개방 고장 검출 알고리즘을 제안한다. 본 논문에서의 해당 모터는 2개의 3상 권선이 30°의 전기적 위상차를 갖고 중성점이 분리된 비대칭 구조를 갖는다. 따라서 듀얼 3상 PWM 인버터와 스위치 개방 고장으로 인한 검출기법이 반드시 필요하다. 본 논문에서는 비대칭 6상 PMSM을 구동하기 위해 듀얼 dq축 전류 제어 방식을 사용하며 전역 통과 필터와 저역 통과 필터를 사용해 전류 변동을 감지하여 개방 고장이 발생한 스위치를 검출하는 방식을 제안한다. 제안한 방법의 효과와 유용성은 여러 실험을 통해 검증하였다.

• Journal of Power Electronics
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• 제17권6호
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• pp.1500-1511
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• 2017

The purpose of this paper is to study a high-performance control scheme for neutral-point-clamping three-level (NPC-3L) inverter fed dual three-phase permanent magnet synchronous motor (PMSM) drives by considering some asymmetric factors such as the non-identical parameters in phase windings. To implement this, the system model is analyzed for dual three-phase PMSM drives with asymmetric factors based on the vector space decomposition (VSD) principle. Based on the equivalent circuits, PI controllers with feedforward compensation are used in the d-q subspace for regulating torque, where the cut-off frequency of the PI controllers are set at the twice the fundamental frequency for compensating both the additional DC component and the second order component caused by asymmetry. Meanwhile, proportional resonant (PR) controllers are proposed in the x-y subspace for suppressing the possible unbalanced currents in the phase windings. A dual three-phase space vector modulation (DT-SVM) is designed for the drive, and the balancing factor is designed based on the numerical fitting surface for balancing the DC link capacitor voltages. Experimental results are given to demonstrate the validity of the theoretical analysis and the proposed control scheme.

• Journal of Electrical Engineering and Technology
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• 제10권6호
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• pp.2326-2333
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• 2015

Stator turn faults in permanent magnet synchronous motors (PMSMs) are more dangerous than those in induction motors (IMs) because of the presence of spinning rotor magnets that can be turned off at will. Condition monitoring and fault detection and diagnosis of the PMSM have been receiving a growing amount of attention among scientists and engineers in the past few years. The aim of this study is to propose a new detection technique of stator winding faults in a three-phase PMSM. This technique is based on the image analysis and recognition of the stator current Concordia patterns, and will allow the identification of turn faults in the stator winding as well as its correspondent fault index severity. A test bench of a vector controlled PMSM motor behaviors under short circuited turn in two phases stator windings has been built. Some experimental results of the phase to phase short circuits have been performed for diagnosis purpose.

• 전력전자학회논문지
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• 제27권4호
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• pp.305-315
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• 2022

In this paper, phase current ripples and torque ripples of six-phase PM synchronous motor controlled by interleaved PWM are analyzed. The cause of the increase of phase current ripple in the interleaved PWM was mathematically analyzed based on the mutual inductance of stator windings and effective voltage vector. Simulation and experiment verified that the DQ current ripple and torque ripple can be reduced by interleaved PWM control. The FFT analysis of torque waveform confirmed that the magnitude of harmonic torque corresponding to double the PWM frequency was reduced.

• 항공우주시스템공학회지
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• 제17권6호
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• pp.100-107
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• 2023

영구자석 동기전동기의 권선 개방 고장은 권선이 끊어지거나 인버터 스위치의 고장으로 발생한다. 권선 개방 고장이 발생하면 전동기에 토크리플과 진동이 발생하게 되며, 영구자석 동기전동기를 작동기로 사용하는 항공기 등을 포함하는 운행체의 안전성에 치명적인 영향을 미치게 된다. 따라서 신속한 고장 검출 및 분류가 필수적이다. 본 논문에서는 영구자석 동기전동기의 권선 개방 고장의 검출과 고장 위치 파악을 위한 분류 기법을 제안한다. 제안된 기법은 확장칼만필터를 통해 고장을 검출 후 다중모델 필터를 통해 고장을 분류한다.

• 전력전자학회논문지
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• 제7권6호
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• pp.579-586
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• 2002

산업용 기기 및 가정용 기기 분야에서 서보 전동기 이용의 급부상으로 인하여 PMSM의 센서리스 제어에 대한 연구가 활발히 연구되고 있다. 센서리스 제어시 그 기초가 되는 것은 역기전력 항이다. 일반적인 센서리스 제어는 역기전력을 추정하고 그 역기전력을 적분하는 형태를 취하여 회전자의 위치를 추정하고 있다. 이 방식에서 두 좌표축의 역기전력 항을 구하기 위해서는 역기전력의 크기와 회전자 위치가 서로 직접적으로 연관되어 있어 두 파라미터를 동시에 정확하게 추정하기는 쉽지 않다. 따라서 본 논문에서는 PMSM의 구동을 위해 필수적인 회전자의 위치 각을 역기전력의 크기의 변수를 사용하지 않는 정규화한 역기전력 항으로 구하는 방법을 제안한다. 또한 실험을 통하여 그 타당성을 입증하였다.

• Journal of Power Electronics
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• 제13권6호
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• pp.985-990
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• 2013

This paper proposes a novel fault diagnosis scheme using parameter estimation of the stator resistance, especially in the case of the open-phase faults of PMSM drives. The stator resistance of PMSMs can be estimated by the recursive least square (RLS) algorithm in real time. Fault diagnosis is achieved by analyzing the estimated stator resistance of each phase according to the fault condition. The proposed fault diagnosis scheme is implemented without any extra devices. Moreover, the estimated parameter information can be used to improve the control performance. The feasibility of the proposed fault diagnosis scheme is verified by simulation and experimental results.

• Smart Structures and Systems
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• 제29권6호
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• pp.799-805
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• 2022

Permanent magnet synchronous motors (PMSMs) are widely used in systems requiring high control precision, efficiency, and reliability. Predicting the remaining useful life (RUL) with health monitoring of PMSMs prevents catastrophic failure and ensures reliable operation of system. In this study, a model-based method for predicting the RUL of PMSMs using phase current and vibration signals is proposed. The proposed method includes feature selection and RUL prediction based on a particle filter with a degradation model. The Paris-Erdogan model describing micro fatigue crack propagation is used as the degradation model. An experimental set-up to conduct accelerated life test, capable of monitoring various signals was designed in this study. Phase current and vibration data obtained from an accelerated life test of the PMSMs were used to verify the proposed approach. Features extracted from the data were clustered based on monotonicity and correlation clustering, respectively. The results identify the effectiveness of using the current data in predicting the RUL of PMSMs.

• 전력전자학회논문지
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• 제6권3호
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• pp.231-242
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• 2001

본 논문에서는 영구자석형 동기 전동기 고정자의 상 권선 인덕턴스에 의하여 지연되는 정현과 서류 지연 성분을 보상함으로써 전동기 발생 토크 특성을 개선하는 방법과 구현 방법을 제시하였다. 이 방법은 축 변환을 사용하지 않기 때문에 하드와이어드 로직에 의하여 구현함으로써 구현이 간단하고 축 변환에 의한 지연을 제거할 수 있다. 특히, 고정자 상 권선 인덕턴스에 의한 지연성분은 전동기 회전 속도에 따라 변화하며, 본 논문에서 제시한 방법을 이용하면 전동기 회전 속도에 따른 동적인 보상을 할 수 있다. 존 논문에서 제시한 방법의 효과를 입증하기 위하여 4극 3상 영구자석형 동기 전동기를 대상으로 실험을 행하였으며, 실험결과 모든 운전 속도에서 발생 토크가 증가함을 확인하였다.