Year-end Sale % OFF 
Abstract
Recently, the dual-permanent-magnet-excited (DPME) machine has attracted growing attention due to its high torque density. Due to the bidirectional field modulated effect (BFME), airgap flux density harmonics (AFDHs) are more complex and abundant than traditional permanent magnet synchronous machines (PMSMs). Moreover, the back-electromotive force (EMF) generated by AFDHs is also complex. Unfortunately, only a few papers qualitatively analyze back-EMF. The qualitative analysis for back-EMF can reveal some important conclusions; for example, only AFDHs meeting specific pole pair numbers (PPNs) can generate back-EMF. However, it may also ignore some details and valuable findings. In this paper, a purely analytical magnetomotive force (MMF) permeance model (PAMPM) for a DPME machine is built to quantitatively analyze the back-EMF. The PAMPM does not require a numerical method, such as conformal transformation. With the PAMPM, AFDHs that contribute to the generation of back-EMF can be recognized and quantified. Interestingly, AFDHs with m <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> p <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> =np <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> cause PM flux-linkage to have a dc bias, and not all AFDHs play a positive role in the generation of back-EMF. The main recognition results are as follows: 1) the S-II and R-II types of AFDHs in a 12/10 DPME machine overall make a negative contribution to the generation of back-EMF; and 2) AFDHs with PPN=22 in the two types mainly cause a negative contribution. To further verify the above results, 2D finite element simulation and experimental tests of a prototype machine are also conducted.
Highlights
Benefiting from the “magnetic gearing effect”, permanentmagnet vernier machines (PMVMs) have the inherent advantage of high torque density and can directly drive the load without the help of intermediate transmission devices such as mechanical gearboxes, making PMVMs outstanding candidates for direct drive applications [1,2,3,4,5,6]
The novelty of this paper is that 1) a PAMPM is established for the DPME machine, and the PAMPM does not require any numerical method, such as the complicated conformal transformation or solving mathematical equations in different subdomains; 2) the general expressions of airgap flux density (AFD), PM flux-linkage (PMFL), and back-EMF are derived based on the PAMPM, which can be used for quantitative analysis and calculations without the help of FEM; 3) the PAMPM and derived expressions are associated with the dimensional parameters, thereby enabling the analysis of the influence of the dimensional parameters on the performance of the DPME machine
By means of the general and purely analytical expressions of AFD and back-EMF, one can recognize and quantify the airgap flux density harmonics (AFDHs) that make a negative contribution to the generation of back-EMF
Summary
Benefiting from the “magnetic gearing effect”, permanentmagnet vernier machines (PMVMs) have the inherent advantage of high torque density and can directly drive the load without the help of intermediate transmission devices such as mechanical gearboxes, making PMVMs outstanding candidates for direct drive applications [1,2,3,4,5,6]. To quantitatively analyze the back-EMF of the DPME machine and recognize and quantify the AFDHs that generate back-EMF, the key is to obtain the expression of the modulated airgap flux density (AFD). The novelty of this paper is that 1) a PAMPM is established for the DPME machine, and the PAMPM does not require any numerical method, such as the complicated conformal transformation or solving mathematical equations in different subdomains; 2) the general expressions of AFD, PM flux-linkage (PMFL), and back-EMF are derived based on the PAMPM, which can be used for quantitative analysis and calculations without the help of FEM; 3) the PAMPM and derived expressions are associated with the dimensional parameters, thereby enabling the analysis of the influence of the dimensional parameters on the performance of the DPME machine. The main contributions of this paper are as follows: 1) Recognizing and quantifying the AFDHs that make a negative contribution to the generation of back-EMF This can help EM designers optimize DPME machines in a targeted manner. This can help EM designers optimize DPME machines in a targeted manner. 2) Defining the contribution rate to evaluate the contribution of different types of AFDHs to back-EMF. 3) Discovering that the AFDHs with m2p2=np cause PM flux-linkage to have a dc bias
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
