# Application Catalog

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2018-06-12

## SPM motor

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241 - Single-Phase Synchronous Motor N-T-I Characteristics Analysis

The widely used three-phase synchronous motor can be driven efficiently and stably but, on the other hand, costs tends to increase from using an inverter. Whereas since single-phase synchronous motors do not require inverters, they can reduce costs. Furthermore, because they are brushless, maintenance costs can also be lowered. In a single-phase synchronous motor, the back emf and the current flowing through the coils change in accordance with the rotation speed of the rotor. At low rotation speed, since the back emf is small, a large current flows through the coils, and magnetic saturation occurs in the magnetic circuit.

Module: DP | 2018-04

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230 - 6-Phase SPM Motor Inverter Fault Simulation

In recent years, multiphase design has been adopted for automotive motors due to the merits of cost reduction and improvement in functions. For example, for power supplies there are 6-phase motors with 3-phase double windings that use two inverters, having a 30 deg phase shift in electrical angle. From this, by using multiple inverters, enhanced redundancy of the in-vehicle motor system is acheived. The motor system can be stopped safely without falling to be in an uncontrollable state even if a failure occurs in a part of an inverter.

Module: DP, RT | 2018-04

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226 - SPM Motor Vibration Characteristics Analysis

The electromagnetic force acting on the motor resonates with the eigenmode of the motor, causing vibration and noise. In order to accurately evaluate this phenomenon, it is necessary to ascertain each frequency and spatial mode in detail regarding the electromagnetic force and eigenmode of the motor. Vibration (acceleration) is obtained by the superposition of electromagnetic force and eigenmode, but since both are physical quantities having vector distributions of space, analysis by means of FEA is useful.

Module: DP, DS | 2018-04

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163 - Torque-Current Curve Analysis of an SPM Motor

One of the fundamental properties of a permanent magnet synchronous motor is the relationship between its current and torque (torque-current curve). The torque generated at each current value is uniform with increases in current up to a certain point, so the torque increases in a linear fashion. However,...

Module:DP | 2013-06

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159 - Sensitivity Analysis of Dimensional Tolerance in an SPM Motor

The corners of magnets used in surface permanent magnet (SPM) motors can be filleted, chamfered, etc. However, it is difficult to maintain exactly the same production in the manufacturing process, and some variation among finished products will occur. Dimensional tolerance is set so as to eliminate...

Module:DP | 2013-10

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124 - Cogging Torque Analysis of an SPM Motor Accounting for Uneven Stator Diameter

When a motor is assembled, the inner diameter of the stator can become uneven because of fabrication errors, shrink fitting, press fitting, etc. Cogging torque increases due to this unevenness, causing vibration and noise.
When a frame is pressed onto a stator core, and when the frame thickness is not uniform...

Module:DP,DS | 2013-06

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120 - Thermal Demagnetization Analysis of an SPM Motor

Exactly how to resolve the problem of rising temperatures is a vital issue when trying to achieve an improvement in a motor's efficiency and output. Among the materials used in a motor, the magnet experiences the greatest variations in properties in relation to temperature. In the case of rare-earth magnets,...

Module:DP | 2014-08

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115 - Eccentricity Analysis of an SPM Motor

Motors have many parts, which must be assembled correctly for a usable product. Even if each part is made within acceptable limits for manufacturing errors, when various parts with small errors are put together, the errors can have a cumulative effect. In particular, if eccentricity (deviation, deflection) occurs in the cylindrical...

Module:DP | 2013-04

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114 - Vibration Analysis of an Outer Rotor Motor

An outer rotor motor has a magnetic rotor that rotates around a stator. The rotor radius of an outer rotor motor is large, so it can produce a larger amount of drive torque than an inner rotor motor with the same diameter, giving it a superior constant velocity.

Module:DP,DS | 2017-10

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108 - Centrifugal Force Rupture Analysis of a Ring Magnet

As the applications for permanent magnet synchronous motors expand in the manufacturing sector, the development of high-speed-capable motors is continuing apace. One problem during high-speed operation is centrifugal force produced in the rotor, because, in an SPM using ring magnets,...

Module:DS | 2013-10

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103 - Efficiency Analysis of a Permanent Magnet Synchronous Motor

A permanent magnet synchronous motor rotates by converting electric energy to mechanical energy.
The important thing when converting energy is efficiency indicated by the power factor for the amount of current effectively used, as well as the percentage of output versus input.

Module:DP,LS | 2017-02

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93 - Cogging Torque Analysis of a Motor with 8 Poles and 9 Slots Accounting for Eccentricity

Eccentricity can occur on the center axis or the rotation axis of a motor. It is advantageous to evaluate the effects of eccentricity because it can cause vibrations and noise and break the symmetry of the magnetic flux density distribution and the electromagnetic force.

Module:DP | 2010-08

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80 - Cogging Torque Analysis of an SPM Motor with Skewed Magnetization

Reductions in vibration and noise are being sought after because they are a cause of torque variations in motors, and demands for reduction are particularly strong with motors that are used in machine tools and power steering. Cogging torque, which is a torque variation that is produced when there is no current,...

Module:TR | 2013-06

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46 - Sensitivity Analysis of the Magnetization Pattern of an SPM Motor

The magnet in a surface permanent magnet (SPM) motor is arranged on the rotor's surface, facing the stator. The motor produces torque from the interaction between the magnetic field produced by the magnet and the magnetic field produced from the excitation coil.

Module:DP,ST | 2013-04

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40 - Cogging Torque Analysis of an SPM Motor

The rotor's rotation in a permanent magnet motor can generate positive and negative torque, even when there is no current flow. This torque is called "cogging torque." While output torque a center of focus in motors used in precision equipment, cogging torque reduction must be taken into account as well. Skew and fractional slots are means of reducing this cogging torque. Skew is a widely used technique that attempts to cancel out cogging torque by applying an appropriate amount of twist to the stator or rotor.

Module:DP | 2018-04

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34 - Demagnetization Analysis of an SPM Motor

Rare earth magnets has characteristics of large energy product, but decrease when using in an area exceeding a knee point causing irreversible demagnetization. For motors, the possibility of thermal demagnetization through thermal stress may occur when the magnet temperature rises due to iron loss or copper loss during rotation.

Module:DP | 2012-04

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31 - Iron Loss Analysis of an SPM Motor Including the Effect of Press-fitting Stress

The laminated structure of a core in a SPM motor can be sustained using press-fitting or shrink fitting. The press-fitting stress needs to be accounted for in the iron loss evaluation because the stress caused by press-fitting is known to increase the iron losses when a magnetic steel sheet is used for the core of the motor.

Module:DP,DS,LS | 2017-10

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30 - Magnetization Analysis of an SPM Motor

A surface magnet type motor (SPM) has direct contact with a stator which generates torque through the interaction of magnetic fields generated by magnets and excitation coils. The magnetization state of a magnet is the main factor which determines the characteristics of a motor. It is important that motor designers...

Module:ST | 2012-04

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29 - Iron Loss Analysis of an SPM Motor with Overhanging Magnet

There are times when permanent magnet motors are designed with a magnet made with overhang, in other words made longer than the stator's stack length, in order to strengthen the magnetic field that it creates. A space is necessary in the stator core to supply the coil ends,...

Module:LS,TR | 2018-06

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24 - Cogging Torque Analysis of an SPM Motor with a Skewed Stator

Reductions in vibration and noise are being sought after because they are a cause of torque variations in motors, and demands for reduction are particularly strong with motors that are used in machine tools and power steering. Cogging torque, which is a torque variation that is produced when there is no current,...

Module:TR | 2013-06

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21 - Iron Loss Analysis of an SPM Motor Including the Effect of Shrink Fitting

A magnetic steel sheet is used for the iron core in a motor. A frame is shrunk into a stator core in order to sustain the laminated structure and to improve the strong joint between the frames. It is know that a compressive stress is generated during the shrinking process which increases the iron loss process.

Module:DP,DS,LS | 2017-10

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20 - Sound Pressure Analysis of an SPM Motor

As electric motors are becoming more common, motors which create less noise are in high demand. Sound can be divided into categories of electromagnetic noise, mechanical noise, and draft noise, where electromagnetic noise is the most common for medium and small sized motors.

Module:DP,DS | 2012-04

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15 - Cogging Torque Analysis of an SPM Motor with a Step Skewed Magnet

Reductions in vibration and noise are being sought after because they are a cause of torque variations in motors, and demands for reduction are particularly strong with motors that are used in machine tools and power steering. Cogging torque, which is a torque variation that is produced when there is no current,...

Module:TR | 2016-06