• Journal of Magnetics
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• v.18 no.3
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• pp.268-275
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• 2013

This paper shows the characteristics of performance for interior permanent magnet machine (IPM) considering driving conditions such as maximum torque per ampere (MTPA) and flux-weakening control especially in terms of harmonic loss. In particular, based on finite element analysis (FEA), permanent magnet (PM) eddycurrent loss and the harmonic iron loss have been computed where the models have been intentionally designed to identify the effects of pole-slot combinations on the loss while maintaining the required power for electric vehicle. From the analysis results, it was shown that the rotor iron loss and PM eddy-current loss of machine employing fractional slot winding are extremely large at load condition. Furthermore, it was revealed that the harmonic iron loss at high-speed operation is mainly distributed over stator teeth and rotor surface, which may aggravate cooling system of the rotor structure in the vehicle.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.2
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• pp.134-143
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• 2016

This paper proposes a novel asymmetrical interior permanent magnet (IPM) brushless DC (BLDC) motor structure, which utilizes half-type permanent magnet (PM) configuration and has asymmetrical side gaps (slot next to the PMs) for reducing torque ripples. This structure uses 24% less volume of PMs than conventional IPM BLDC motor with a full set of magnets. The characteristics of the proposed motor are compared with three other half-type IPM BLDC motors through finite elements method (FEM) analysis, and the usefulness of the proposed motor was verified through experimental evaluation on prototypes of the conventional motor and proposed motor under various torque load conditions. This research obtained a high-performance IPM BLDC motor while decreasing manufacturing cost at the same time.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.5
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• pp.949-954
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• 2011

This paper presents a comparative study on motor characteristics with specific consideration of radial vibration force in interior permanent magnet synchronous motors (IPMSM) according to pole/slot combinations. Three IPMSM models, 16-pole/15-slot design, 16-pole/18-slot design and 16-pole/24-slot design are built, in which 16-pole/15-slot and 16-pole/18-slot designs provide high winding factor and 16-pole/24-slot design is known as a general pole/slot combination. By coupling finite element analysis (FEA) with equivalent circuit method, motor characteristics, back electro-motive force (Back-EMF), inductances, cogging torque, etc. as well as machine output performances are analyzed and compared. The radial vibration force (RVF) distribution in air gap causing stator vibration and noise is interested. It is expected that this study help with appropriate choice of pole/slot combination in IPMSM design.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.2
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• pp.216-222
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• 2012

Newly proposed RG-MADS (Randomly Guided Mesh Adaptive Direct Search) has been applied to the optimal design of Interior Permanent Magnet Synchronous Motor (IPMSM) which has the distinctive features of magnetic saturation. RG-MADS, advanced from classical MADS algorithm, has the superiority in computational time and reliable convergence accuracy to the optimal solution, thus it is appropriate to the optimal design of IPMSM coupled with time-consuming Finite Element Analysis (FEA), necessary to the nonlinear magnetic application for better accuracy. Effectiveness of RG-MADS has been verified through the well-known benchmark-functions beforehand. In addition, the proposed RG-MADS has been applied to the optimal design of IPMSM aiming at maximizing the Maximum Torque Per Ampere (MTPA), which is regarded as representative design goal of IPMSM.

• Journal of Power Electronics
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• v.9 no.2
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• pp.188-197
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• 2009

This paper presents an adaptive flux observer to estimate stator flux linkage and stator inductances of an interior permanent-magnet synchronous machine considering magnetic saturation. The concept of static and dynamic inductances due to saturation is introduced in the machine model to describe the relationship between current and flux linkage and the relationship between their time derivatives. A flux observer designed in the stationary reference frame with constant inductance is analyzed in the rotor reference frame by a frequency-response characteristic. An adaptive algorithm for an on-line inductance estimation is proposed and a Lyapunov-based analysis is given to discuss its stability. The dynamic inductances are estimated by using Taylor approximation based on the static inductances estimated by the adaptive method. The simulation and experimental results show the feasibility and performance of the proposed technique.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.4B no.4
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• pp.211-216
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• 2004

Inductance characteristics, torque variations and ripple according to current, and position of multi-layer buried magnet synchronous machines with field-weakening operations are presented. The rotor structure optimal design of a buried magnet synchronous machine with high performance is investigated, and optimization results and comparison among design candidates are shown. For the fast and accurate search of multiple optima, the auto-tuning niching genetic algorithm is used and a final solution is selected considering various design factors.

• Journal of Electrical Engineering and Technology
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• v.4 no.2
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• pp.240-248
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• 2009

An approach to control the position for an interior permanent magnet synchronous motor (IPMSM) based on an adaptive integral binary observer is described. The binary controller with a binary observer is composed of a main loop regulator and an auxiliary loop regulator. One of its key features is that it alleviates chatter in the constant boundary layer. However, steady state estimation accuracy and robustness are dependent upon the thickness of the constant boundary layer. In order to improve the steady state performance of the binary observer and eliminate the chattering problem of the constant boundary layer, a new binary observer is formed by adding extra integral dynamics to the existing switching hyperplane equation. Also, the proposed adaptive integral binary observer applies an adaptive scheme because the parameters of the dynamic equations such as the machine inertia and the viscosity friction coefficient are not well known. Furthermore, these values can typically be easily changed during normal operation. However, the proposed observer can overcome the problems caused by using the dynamic equations, and the rotor position estimation is constructed by integrating the rotor speed estimated with a Lyapunov function. Experimental results obtained using the proposed algorithm are presented to demonstrate the effectiveness of the approach.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.71-80
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• 2007

A control approach for the sensorless speed control of interior permanent magnet synchronous motor(IPMSM) based on adaptive integral the binary is proposed. With a main loop regulator and an auxiliary loop regulator, the binary observer has a property of the chattering alleviation in the constant boundary layer. However, the width of the constant boundary limits the steady state estimation accuracy and robustness. In order to improve the steady state performance of the binary observer, the binary observer is formed by adding extra integral augmented switching the hyperplane equation. By mean of integral characteristics, the rotor speed can be finely estimated and utilized for a sensorless speed controller for IPMSM. The proposed adaptive integral binary observer applies an adaptive scheme, because the parameters of the dynamic equations such as the machine inertia or the viscosity friction coefficient is not well known and these values can be easily changed generally during normal operation. Therefore, the observer can overcome the problem caused by using the dynamic equations, and the rotor speed estimation is constructed by using the Lyapunov function. The experimental results of the proposed algorithm are presented to demonstrate the effectiveness of the approach.

• Journal of Electrical Engineering and Technology
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• v.13 no.5
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• pp.1945-1955
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• 2018

High frequency signal injection (HFI) is an alternative method for estimating rotor position of interior permanent magnet synchronous motor (IPMSM). The general method of frequency and amplitude selection is based on error tolerance and experiments, and is usually set with only one group of HF parameters, which is not efficient for different working modes. This paper proposes a novel rotor position estimation scheme by HFI with optimized frequency and amplitude, based on the mathematic model of IPMSM. The requirements for standstill and low-speed operational modes are met by applying this novel scheme. Additionally, the effects of the frequency and amplitude of the injected HF signal on the position estimation results under different operating conditions are analyzed. Furthermore, an optimization method for HF parameter selection is proposed to make the estimation process more efficient under different working conditions according to error tolerance. The effectiveness of the propose scheme is verified by the experiments on an IPMSM motor prototype.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1587-1588
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• 2007

IPM(Interior Permanent Magnet) Machine의 전류 제어는 자기저항에 의존하는 토크특성 때문에 SPM(Surface Permanent Ma- gnet) Machine보다 복잡하다. 고성능 토크제어를 위해서는 d축 전류와 q축 전류의 동특성간의 상태 decoupling이 요구된다. 그러나 전류의 상태 동특성이 coupling된 인덕턴스의 변화(온도, 파라미터들의 부정확한 측정값)는 상태 decoupling을 어렵게 한다. 그래서 이러한 변화와 각각의 전류가 독립적으로 제어될 수 있게 여러 decoupling 방법들에 초점이 맞춰지고있다. 본 연구는 외란에 강하고, 특히 인덕턴스의 변화와 상관없는 이상적인 토크제어를 하기 위해 신경회로망을 이용하여 슬라이딩 평면(sliding surface)을 구성하고, SMC(Sliding Mode Control)를 이용하여 상태 cross-coupling의 decoupling을 위한 새로운 접근을 제안한다. 이 방법은 PI제어 성능과 SMC의 강인성을 알고리즘을 이용하여 결합한 것이라고 볼 수도 있다.