Analysis of a New Double-sided Flux Reversal Arc Structure Permanent Magnet Machine Using Analytical Approach
School of Electrical Engineering, Southeast University, Nanjing, P. R. China
This paper presents an analytical approach to calculate the electromagnetic performances of the new double-sided flux reversal (FR) arc structure permanent magnet (PM) machine (DS-FRAPMM). The DS-FRAPMM incorporates the merits of the arc structure PM machine and the FRPM machine, which is applied on some scanning drive systems. The machine topology and operation principle of the DS-FRAPMM are firstly proposed. Then, the analytical models of the magnet magnetomotive force (MMF) and air-gap permeance accounting for stator and rotor slots are obtained by using Fourier series expansion method. The flux density can be calculated based on the MMF and the air-gap permeance analytical models. Finally, finite element analysis (FEA) is used to validate the analytical results. The comparison results show that the predicted results obtained by the analytical approach match well with the FEA results.
Fast Estimation of Harmonic Losses Caused by Inverter Carrier in Interior Permanent Magnet Synchronous Motors by Using Combination of Time and Frequency Domain Finite Element Analyses
Chiba Institute of Technology, Japan
This paper describes a fast calculation method for harmonic losses caused by inverter carrier in interior permanent magnet motors for characteristic estimation of the motors under large number of driving conditions. In the proposed method, harmonic loss caused by the largest component of the harmonic voltage is calculated by linear frequency domain analysis with the differential permeability distribution obtained by time domain analysis. The total carrier loss is predicted by the variation of this largest harmonic component and sum of the square of harmonic voltages. The proposed method is applied to the efficiency map calculation of an interior permanent magnet motor. It is clarified that the total computational time is reduced as nearly 1/20 as compared with the conventional method.
Loss Calculation and Thermal Analysis of Permanent-Magnet Synchronous Motors for Articulated Robot Applications
1University of Science and Technology, Korea, Republic of (South Korea); 2Korea Electrotechonology Research Institute, Korea, Republic of (South Korea)
Smaller and lighter motors are needed to be used for cooperative robots, which are becoming a recent issue among articulated robots. In order to make the motor small, the axial length must be reduced within a limited diameter, so a reduction in the length of the core lamination and the winding end length must be considered. However, loss and thermal analysis are essential in the design process, as loss increases to meet output with excessive volume reduction and may consequently increase temperature severely. In this paper, the loss values for various analytical models studied to reduce the axial length are calculated, and the thermal behavior is predicted by the analytical lumped-circuit method. Models with low-temperature rise among several analytical models were selected, and the predicted temperature rise was compared to the measured results and found to be quite consistent.
Characteristics Comparison of 3kW, 100,000 rpm Brushless DC and AC Motors for Turbocharger with an Additional Electrically Driven Compressor
1University of Science and Technology, Republic of (South Korea); 2Korea Electrotechnology Research Institute, Republic of (South Korea); 3Kyungsung University, Republic of (South Korea)
The Korea Electrotechnology Research Institute is developing a high speed surface mounted permanent magnet synchronous motor (SPMSM), which is known as the brushless AC (BLAC) motor, and a pulse width modulation (PWM)-driven inverter for turbocharger with an additional electrically driven compressor (TEDC). These systems operate at a power of 3 kW at 100,000 rpm and is intended to fit 1,600 cc diesel vehicles to reduce turbo-lag to within 0.5 s. In order to reduce cost for commercialized, we are developing the brushless DC (BLDC) motor because of easier control method. Samarium cobalt magnets were used at BLDC and BLAD motor. It is difficult to be magnetized to radial direction for these magnets, so the permanent magnets were divided to 8 segments which were magnetized to diametric direction to emulate radial direction magnetization. Also, 2-dimensional finite element analysis (FEA) was conducted considering eccentricity and one-way coupling multiphysics analysis was carried out to confirm the vibration. As a result, several resonance points were found at low speed. In the actual performance evaluation, the low speed section was passed quickly to avoid resonance and the motor performance was satisfied with the design specification.
Investigation and Control of a Linear Switched Reluctance Motor with Segmented Secondary Driving System
Shandong University, China, People's Republic of
The linear switched reluctance motor with segmented secondary(LSRMSS) is a new kind of brushless double salient motor, which is developed from linear switched reluctance motor(LSRM). The motor structure of the LSRMSS is rugged and robust with no winding or permanent magnets on it. It effectively avoids the drawbacks of complex structure and high manufacturing cost. This paper presents a new control strategy for the LSRMSS. The new control strategy based on force distribution function effectively improves the operational stability of LSRMSS.
A Study on the Improvement of the Correction Coefficient Considering the 3D Effect of Spoke Type Permanent Magnet Synchronous Motor
1Busan University of Foreign Studies, Korea, Republic of (South Korea); 2Halla University, Korea, Republic of (South Korea); 3Dongyang mirae University, Korea, Republic of (South Korea); 4Gachon University, Korea, Republic of (South Korea)
Spoke type permanent magnet synchronous motor (PMSM) with high power density has a magnetic path in the axial direction at the upper and lower ends of the motor stack unlike the general PMSM in which the magnetic path exists only on the 2D plane. Due to this 3D magnetic path, the spoke type PMSM cannot be analyzed accurately by the conventional 2D finite element analysis (FEA). In this paper, we propose a new 2D FEA analysis method which can obtain the same level of analysis results as 3D FEA by deriving the correction coefficient which can consider the 3D effect.
Modelling Incipient Inter-Turn Short Circuit Fault in Permanent Magnet Synchronous Motors
University of Agder, Norway
The inter-turn short circuit (ITSC) fault in the winding of a 1.7 KW permanent magnet synchronous motor (PMSM) is modelled using a time-stepping finite-element analysis (FEA).. Conventional FEA normally consider the fault symmetrical, but ITSC faults may initiate in one coil and then expand to other coils. Analysis of a machine under incipient faults is important to find which motor signals are useful for fault detection. To do this, numerical data obtained from FEA are analyzed using fast Fourier transform in this work.
Analytical Modeling of Consequent-Pole Reluctance Machine with Improved MMF-Permeance Method
School of Electrical Engineering, Southeast University, Nanjing, 210096, People's Republic of China
This paper proposes an analytical modeling for consequent-pole reluctance machine (CPRM) having permanent magnets (PMs) alternately located on stator poles. The analytical approach is established by combing the magneto-motive-force (MMF) permeance based model and simplified magnetic circuit. The proposed analytical modeling allows a rapid estimation of the electromagnetic characteristics of the CPRM, e.g., the stator/rotor permeance distributions and open-circuit air-gap flux density. The effectiveness of the proposed analytical method is validated by finite-element analysis (FEA) results.
Dynamic Characteristic Analysis of a Novel Fast-Operation Permanent Magnet Actuator for 10kV Vacuum Circuit Breakers
Southeast University, China, People's Republic of
This paper proposes a novel fast-operation permanent magnet actuator (PMA) for 10kV vacuum circuit breaker. The proposed PMA combines a conventional monostable multi-magnetic circuit actuator and an auxiliary actuator, which can fulfill the normal operation and reclosing operation. When in reclosing process, the breaking time is shortened by reducing the holding force of permanent magnet. The dynamic characteristics of the proposed PMA are analyzed by equivalent magnetic circuit method, including displacement and speed of the movable iron core, and so on. These calculated results prove that the breaking time of the proposed PMA can be obviously reduced.
Optimization of Reluctance Motor with Printed Rotor
University of West Bohemia, Czech Republic
A novel way of optimizing a reluctance motor with rotor manufactured by 3D printing technology is presented. The optimization
algorithms must take into account the tolerances of its production that are generally higher compared with classical processing,
which requires a high level of robustness. The paper presents the complete 3D mathematical model of the forward and backward
tasks together with the ways of their numerical solutions. The methodology is illustrated with a typical example.
Transient Electromagnetic Field Distribution of the Single-Stage Fast Linear Transformer Driver with Coaxial Barrel and 24 Separate Columns Structure
1Xi'an Jiaotong University, China, People's Republic of; 2Northwest Institute of Nuclear Technology, China, People's Republic of
Fast linear transformer drivers (FLTDs) are a developing pulsed-power technology with modular and compact structure. In this paper, the dynamic pulsed power discharging process of a single stage FLTD is simulated and tested. Two different current return approaches are proposed: the coaxial outer barrel and the 24 separate columns. In addition, corresponding 3D full-size models of the single stage FLTD with common cavity shell have been constructed based on the finite element method (FEM). Output performance such as the load current and load voltage of the two single-stage FLTD is in good agreement with the experimental result. Electromagnetic field distributions are obtained and analyzed at different time instants. Simulation results indicate that output performance of the two current return structures is very close and the 24 separate columns can be a valid alternative to coaxial barrel.
Analysis of Axial Field Switched Flux Memory Machine by a Combined Analytical Method
1School of Electrical Engineering, Southeast University, Nanjing, 210096, People's Republic of China; 2Department of Electrical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
This paper proposes a combined analytical method for a novel axial field switched flux memory machine (AF-SFMM). This analytical method is characterized by combing the quasi-3-dimensional (quasi-3D) finite element analysis (FEA) and magneto-motive-force (MMF) permeance method. Compared with conventional time-consuming 3D FEA, the proposed method can improve the effcient computation signicantly, which can be well applied in the prameter initialization stage. Meanwhile, The effectiveness of the proposed analytical method is validated by FEA results.
Parameter Identification and Application of Equivalent Circuit at Low Frequency of Oil-paper Insulation in Transformer
1School of Electrical Engineering and Automation, Wuhan University, Wuhan, People's Republic of China; 2College of Electrical and Information Engineering, Anhui University of Science and Technology, Huainan, People's Republic of China; 3School of Electrical and Electronic Engineering, Hubei University of Technology, Wuhan, People's Republic of China
The low frequency section of frequency dielectric spectroscopy (FDS) can effectively reflect the aging state of the oil-paper insulation system. However, in actual measurement, it is time-consuming and poor accessibility, thereby restraining its field applications. Aim at this problem, this paper proposed a method to calculate the tanδ under 10-3 Hz. A low frequency equivalent circuit model is established to characterize the polarization process at low frequency in the oil-paper insulation. The simulated annealing particle swarm optimization (SAPSO) algorithm is used to identify the parameters in equivalent circuit. Compared with the experimental results, the tanδs under 10-3 Hz, which are calculated by the identified parameters, are less than 2.5%. This method can greatly avoid the impact from external environment and reduce the measurement time. The calculated value can provide reference for the aging assessment of oil-immersed paper.
3-D Analytical Magnetic Field Analysis of the Eddy Current Coupling With Quasi-Halbach Magnets
Hohai University, China, People's Republic of
This paper presents a 3-D analytical magnetic field analysis of a 300kW eddy current coupling with quasi-Halbach magnets. Analytical magnetic distributions in the conductor and air gap region of the coupling are predicted by employing a group of H-formulations in the conductor region and Laplacian equations with magnetic scalar potential in other regions in the Cartesian coordinate. Analytical results of magnetic field distributions and the electromagnetic force are derived and verified by the numerical computational by 3D finite element models in both Cartesian and cylindrical coordinate.
Calculation of the Inductances of an Ironless Rotor Using a Discrete Elements Model
University of Erlangen-Nuremberg, Germany
Ironless windings often come along with a rather complex winding geometry compared to a regular dc-machine with slotted rotor. Therefore, it often is more difficult to derive an analytical solution for the self- and mutual-inductances of a rotor with ironless windings. To overcome the complexity of the geometry, in this paper, the single wires of the winding are split into discrete elements, each of them representing a small piece of copper. With the help of these elements, the inductances of the rotor are calculated by using the magnetic vector potential and the magnetic energy. Finally, the calculated values are compared to the measured values of the real winding body.
A Study on Temperature Rise Evaluation Using the Superposition Test in Low Voltage High Power Induction Motors
1Rotating M/C Innovation Tech. Team, Hyosung Heavy Industries, Changwon 51529, Korea; 2Department of Electrical Engineering, Hoseo University, Asan 31499, Korea
The temperature saturation of induction motors is determined in proportion to the losses of the motors. There are several methods for temperature rise test, but in this paper, two methods which are widely used in the industrial fields are discussed. The methods are the load and the superposition test, respectively. Among them, the superposition test has a critical limit in predicting the temperature rise of the induction motor. Accordingly, a computational method is applied in order to prove the limitations of the superposition test method. Moreover, the variation of the motor losses according to the superposition frequency is compared in this paper. Two temperature rise tests, including finite element analysis, are performed to clarify the limitation of the superposition method and confirm the consistency of the results. In this paper, the temperature rise results measured by the dynamometer and by the superimposition method are compared, respectively. By comparing the two results for the same model, the validity of the analytical approach to the temperature rise testing is verified.
Analysis of Energizing Switching Time of Transmitter Unit for Dynamic Wireless Charging of Electric Vehicles
Tianjin Key Laboratory of Advanced Technology of Electrical Engineering and Energy, Tianjin Polytechnic University, Tianjin, China
On the multi-transmitting coils, single receiving coil wireless power transmission system, multi-transmitting coils work alternately is an effective way to improve the energy efficiency of the dynamic wireless charging system for EVs. Firstly, the paper inferred the mutual inductance expression of dynamic coupling process, and then obtained the conclusion that mutual inductance will change with displacement and then affect the transmitted power. Secondly, to reduce mutual inductance fluctuation and improve the stability of power transmission, a power supply scheme is proposed. Thirdly, in dual-transmitting and single-receiving system, the optimal switching time is obtained on the principle of reducing mutual inductance fluctuation when receiver moves between two transmitters, that is, the receiving coil moves to the middle point of two transmitting coils for switching. The last part presents the testing of the proposed system on a laboratory scale prototype and shows that the best switching time can significantly improve the energy efficiency of wireless power systems.