Yinquan Yu

Incline Unbalanced Magnetic Pull Induced by Misalignment Rotor in PMSM

This paper analyzes the incline unbalanced magnetic pull (IUMP) generated in the permanent magnetic synchronous motor (PMSM) with the rotor misalignment. The motor magnetic field in such a motor is asymmetric, and both the magnitude and the action point of UMP vary in motor operation. This paper presents an analytical model for analyzing the 3-D effects of the UMP induced by the misalignment rotor. The numerical simulation results prove the effectiveness of the proposed analytic model.

Natural Frequency of Stator Core of PM Synchronous Motor

As the degree of office automation to improve, more and more automation equipments are utilized in office. Moreover, numbers of motors are employed in automation to realize multiple functions to attract customers. As a result, the motor which can run more quietly are highly demanded than ever. One of the main causes of noise production in motors is resonance between the electromagnetic forces e.g. Unbalanced Magnetic Pulls (UMPs) and the stator and the frame of the motor. Therefore, the accurate determination of the natural frequencies of stator at the design stage becomes very important [1]. Researchers have studied motor natural frequencies, vibration and acoustic signals in recent years [2]–[5]. In this paper, the PMSM stator mathematic model has introduced and validated by 12 slots and 5 pole-pairs PM surface mounting Synchronous motor M1 simulation case study. The dynamic responses of the model with high frequency excitation force are studied through simulation and experimental approach to further validate the analytical model.Copyright

Synthesis of a novel linear-rotary electromagnetic induction sensor using printed circuit coils

Encoders and resolvers are the commonly used sensors to measure the shaft position in motion control applications. Requirements of precise manufacturing and special electromagnetic or optic structures make those sensors expensive. Reduction of cost without degradation of performance is a challenging problem in sensor design. It demands novel and innovative designs to be explored. This paper presents the synthesis of a novel linear-rotary electromagnetic induction sensor using printed circuit coils. The operating principle of the new sensor adapts that of a resolver but the new sensor outputs have a piece-wise linear relationship with the shaft position. In this work, systematic design procedures are described and the prototypes are fabricated. Evaluation of the prototypes shows that the new sensor achieves the accuracy comparable to the accuracy of industrial resolvers.

Diagnosis of crack of rotor blades with genetic method

A methodology of modeling and simulation of rotor blades by using force vibration finite element method is presented. The experiments were conducted with 3D-LDV for verifying the analysis results. The measurements confirm the effectiveness of the modeling and simulation method presented. When Genetic Programming (GP) method and the data base created by the model are used, the accuracy of prediction of crack of the blades generated in the motor/generator operation can be improved.

Analysis of magnet field degradation on PM motor vibration

In this paper, the effect of magnet field degradation on vibration of the permanent magnet (PM) motor is analyzed. Combination of 2D and 3D FEM is carried out to identify the electromagnetic vibration sources. Vibration signals are analyzed by electromagnetic (EM) field coupled vibration analysis. Results are useful in optimal motor design for PM motor to minimize vibration and to detect the magnet field degradation failure in online and offline monitoring.

Analytical and Numerical Study Rotor Faults in PM Synchronous Motor

In order to achieve high area density of HDD to 10Tbit/in2, both radial and axial direction Repeatable Run-Out (RRO) and None repeatable Run-Out (NRRO) of spindle motor in HDD should be significantly reduced. That means the high performance spindle motor is need. Currently, the spindle motor used in HDD uses a rotating shaft FDB which structure likes slender cantilever beam to support the rotor and the problem of this kind of structure is reported in [1]. This structure cannot meet HDD high TPI requirements and should be replaced by the fixed shaft FDB spindle motor and the analytical model is shown in Fig. 1. Moreover, different types of Unbalance Magnetic Pull (UMP) of the Spindle motor and induced vibration should be fully studied. In order to fully understand motor vibration behavior, a thorough theoretical derivation of motor dynamics should be carried out as they can disclose clearly the global performance of the motor. Generally, four types of UMP reported in [1]–[3] can generate the motor lateral and axis vibration and produce motor acoustic noise. Researchers have studied vibration and acoustic signals in recent years[1]–[6]. In this paper, the PMSM mathematic model has introduced and validated by 12 slots and 5 pole-pairs PM surface mounting Synchronous motor M1 simulation case study. This type of Permanent Magnetic Synchronous motor (PMSM) is using in many applications, e.g.Copyright

Vibration Study and Classification of Rotor Faults in PM Synchronous Motor

Both radial and axial direction Repeatable Run-Out (RRO) and none repeatable Run-Out (NRRO) of spindle motor in HDD is a big concern in high TPI requirement. Besides the reasonable spindle motor structure design which studied in [3]–[4], the fabrication tolerance of spindle motor parts should be controlled in order to minimum RRO and NRRO. As it is known, the vibration of spindle motor is mainly caused by unreasonable Unbalance Magnet Pull (UMP). Different motor parts faults (tolerance is out of the control) will generate different types of UMP which should be generate different vibration signals pattern. Though studying different vibration signals and acoustic noise pattern, the types of UMP or other faults should be detected and classified. then, the related out of tolerance controlled parts can be known. Researchers have studied vibration and acoustic signals in recent years [5][6]–[7]. In this paper, the 12 slots and 5 pole-pairs PM surface mounting Synchronous motor is modified as M1 to do experimental study. This paper can be a guideline of design high performance motor; it also can be the reference of general motor fault diagnosis.Copyright

Influence of axial asymmetrical rotor in PMAC motor operation

To the permanent magnetic (PM) AC motor with the rotor aligned asymmetrically in axial direction, the motor magnetic field is axial-asymmetric. This asymmetric field generates unbalanced magnetic pull (UMP), and the analysis shows that, the UMP value varies in the motor operation. Analysis shows also that, if the number of stator slot is odd, the UMP center varies in the motor operation. The paper presents an analytical model for analyzing the effects of the UMP induced by the axial-asymmetrical rotor. The numerical results of PMAC motors are also presented, and they confirm the effectiveness of the analytical UMP model presented.