• 전기학회논문지
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• 제65권6호
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• pp.987-994
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• 2016

In this paper, we present a comparative analysis of surface-mounted permanent magnet synchronous motors (SPMSM) and interior permanent magnet synchronous motors (IPMSM). First, we use 2D finite element analysis (FEA) to analyze models satisfying the same rated conditions according to the torque-speed curve characteristics, which are determined from the operating conditions. Next, we manufacture an SPMSM and IPMSM having good performances from an electromagnetic perspective based on analysis results, namely the cogging torque, torque ripple, and efficiency. We analyze both of the manufactured machines when they are connected back-to-back and when they are used as a motor and a generator, respectively. The motor is driven by a commercial inverter and the generator is connected to a three-phase resistance load bank. Finally, based on experimental results, which include the total harmonic distortion (THD) of the back electro-motive force (EMF), cogging torque, efficiency, and mass, we determine the motor that is most suitable under requirements.

• 전기학회논문지
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• 제65권11호
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• pp.1806-1812
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• 2016

We propose an interior permanent magnet syhchronous motor (IPMSM) with arc-shape ferrite permanent magnets (PMs) as a substitute for the rare-earth permanent magnet, and determine its optimal design through parametric study. First, we use 2D finite element analysis to analyze 4-poles and 6-slots initial model according to performance requirements and design parameters. The current angle of the maximum average torque considered in the analysis is different compared with the current angle of the minimum torque ripple. Thus, the parametric study for optimal rotor design is performed by varying the thickness and the offset radius of the PMs according to current angle. In particular, a narrow bridge is required in conventional IPMSM for reducing flux leakage; however, the increase in cogging torque in the analysis model saturates the narrow bridge (large offset radius). Therefore, we suggest an appropriate shape considering limiting conditions such as DC link voltage, average torque, torque ripple, and cogging torque taking into account performance requirements.

• Journal of Electrical Engineering and information Science
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• 제3권1호
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• pp.103-109
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• 1998

A new flux-weakening scheme for an Interior Permanent Magnet Synchronous Motor (IPMSM) is proposed. This control scheme enables the maximum torque operation for the fast acceleration in the constant power region according to the current and voltage limit condition. Especially the dynamic performance of the braking in the flux-weakening region is improved with the compensation of the stator resistance. Also since the onset of the flux weakening operation is adjusted according to the load conditions, the machine parameters, and whether motoring or braking region, the stable and precise transition operation into or out of the flux weakening region can be achieved. The effectiveness of the proposed scheme is verified through experiments with an IPMSM drive system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.821-822
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• 2006

In the case of the interior permanent magnet synchronous motor (IPMSM), it is important to know the accurate machine parameters in the design step. In particular, d- and q- axis inductance are expected to have ripple characteristics, due to the mechanical structure and the degree of magnetic saturation. In this paper, this feature is expressed as inductance variation. Inductance variation of the IPMSM is calculated with finite element analysis, and the reason for inductance variation is identified. Finally the validity of this paper is verified by the comparison with the experimental results.

• Journal of Electrical Engineering and Technology
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• 제13권6호
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• pp.2276-2283
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• 2018

A 50kW-4000rpm interior permanent magnet synchronous machine (IPMSM) applied to the high-performance electric vehicle (EV) is introduced in this paper. The main work of this paper is that a 2-D T-type lumped-parameter thermal network (LPTN) model is presented for IPMSM temperature rise calculation. Thermal conductance matrix equation is generated based on calculated thermal resistance and loss. Thus the temperature of each node is obtained by solving thermal conductance matrix. Then a 3-D liquid-solid coupling model is built to compare with the 2-D T-type LPTN model. Finally, an experimental platform is established to verify the above-mentioned methods, which obtains the measured efficiency map and current wave at rated load case and overload case. Thermocouple PTC100 is used to measure the temperature of the stator winding and iron core, and the FLUKE infrared-thermal-imager is applied to measure the surface temperature of IPMSM and controller. Test results show that the 2-D T-type LPTN model have a high accuracy to predict each part temperature.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제4B권4호
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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.

• 전기학회논문지
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• 제61권2호
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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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• 제9권3호
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• pp.438-446
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• 2009

The performance of direct torque controlled (DTC) interior permanent magnet (IPM) machines is poor at low speeds due to a few reasons, namely limited accuracy of stator voltage acquisition and the presence of offset and drift components in the acquired signals. Due to factors such as forward voltage drop across switching devices in the three phase inverter and dead-time of the devices, the voltage across the machine terminals differ from the reference voltage vector used to estimate stator flux and electromagnetic torque. This can lead to instability of the IPM drive during low speed operation. Compensation schemes for forward voltage drops and dead-time are proposed and implemented in real-time control, resulting in improved performance of the space vector modulated DTC IPM drive, especially at low speeds. No additional hardware is required for these compensators.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권11호
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• pp.547-554
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• 2006

The detent force of a permanent magnet linear motor(PMLM) consists of the end force and cogging force, and should be reduced for high precision purpose applications. The cogging force comes from the electromagnetic interaction between the permanent magnets and interior teeth(or the slots) of the stator, and of which the magnitude depends on the ratio of the numbers of the armature and permanent magnet poles as well as the geometrical shape of the permanent magnet and armature pole. In order to reduce the cogging force of a PMLM, this paper proposes a new configuration which has 9 permanent magnet poles and 10 armature winding slots. By theoretical investigation of the principle of cogging force generation and simulating using finite element method, the proposed PMLM configuration is proven to give much less cogging force than the conventional configuration which has 8 permanent magnet poles and 12 armature winding slots. A proper winding algorithm, modified (A, A, A) winding method, for the proposed configuration is also suggested when the proposed PMLM is operating as a 3 phase synchronous machine. A theoretical and numerical calculation shows that the proposed configuration makes slightly bigger back-emf and thrust force under same exciting current and total number of winding turns condition.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.857_858
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• 2009

On account of small size and light weight, a high-speed machine is regarded as a key technology for many future applications of drive systems. In high-speed applications, permanent magnet (PM) synchronous motors have a number of merits such as high efficiency and high power density. Accordingly, they are suitable for driving the air-blower of a fuel cell electric vehicle (FCEV) where space and energy savings are critical. Particularly, a surface-mounted PM motor of them is mainly used as a high-speed machine. However, the motor has a fatal flaw owing to a retaining can to maintain the mechanical integrity of a rotor assembly. The can results in the increase of magnetic air-gap length in the surface-mounted PM motor. Thus, in this paper, an interior PM motor is designed in order to drive the air-blower of FCEV instead of the surface-mounted PM motor, and the experimental results of two models are compared to verify the capability of the interior PM motor for a high-speed machine.