Sensitivity Analysis and Optimal Design of a Stator Coreless Axial Flux Permanent Magnet Synchronous Generator

Abstract

In this paper, the modified initial design procedure and economic optimization design of a stator coreless axial flux permanent magnet synchronous generator (AFPMSG) are presented to improve the design accuracy, efficiency, and economy. Static magnetic field finite-element analysis (FEA) is applied to the magnetic equivalent circuit (MEC) method to increase the accuracy of electromagnetic parameters and reduce the iteration times. The accuracy and efficiency of the initial design is improved by the combination of MEC method and static magnetic field FEA in the design procedure. For the economic optimization, the permanent magnetic (PM) material volume model, which affects the cost of the AFPMSG the most, is derived, and the influence degree of the main structure parameters, to the performance, is distinguished and sorted by sensitivity analysis. The hybrid genetic algorithm that combines the simulated annealing and father-offspring selection method is studied and adopted to search for the best optimization solution from the different influence degree and nonlinear interaction parameters. A 1 kW AFPMSG is designed and optimized via the proposed design procedure and optimization design. Finally, 3D finite-element models of the generator are simulated and compared to confirm the validity of the proposed improved design and the generator performance.

A systematic review on current research and developments on coreless axial‐flux permanent‐magnet machines

“…The impact of magnet shape and circumferentially magnetised magnets buried inside the rotor surface on the coreless SSDR topology has been investigated [14,46]. For coreless SSDR AFPM machines in small scale portable applications, a discussion was made about design [16,[47][48][49][50][51][52][53][54][55][56], optimisation [28,50,57] and modelling [58,59]. In Ref.…”

“…[120], a multiphase concept in the coreless stator in AFPM machines was introduced for the first time, where design optimisation was done for coreless stator AFPM topology by using Litz wire and PCB stator. Using coreless stator in AFPM machine, prototype implementation had been performed for the issue of analytical analysis [59], design and optimisation [2,28,50,74], electromagnetic and thermal analysis [55], winding design [16], coil pole ratio [56], sensitivity analysis [57], eccentricity and demagnetising fault analysis [64], structural analysis [75] and comparative analysis [58]. Coreless stator windings are suitable for use either with SSDR or DSSR topology.…”

“…Challenges of coreless AFPM topology with strategies to overcome core in the stator eliminates core loss the stator coils are directly exposed to the time-varying main magnetic field that may instigate eddy current generation in the stator conductors. This eddy current may cause a significant loss[126] Non-conventional conductors, such as 'carbon nano tubes (CNTs)' and 'Litz wire' can overcome some of the problems associated with copper For coreless stator, the effective air gap length is larger and requires more active PM material to keep the magnetic field in the air gap, which increases the cost of the AFPM[57] With the same PM volume, MSMR topology can be a solution to minimising the extra cost Coreless stator reduces the stator flux linkage[29] Rotor flux concentration techniques (using Halbach magnets) are essential for improving the stator flux linkage…”

Design and Analysis of Coreless Axial Flux Permanent Magnet Machine with Novel Composite Structure Coils

“…The AFPM machine has a variety of classical structures; wherein, the configuration with double rotors and a single stator is preferred chiefly [4,5], and the stator core is not necessarily required to form a closed magnetic circuit in the design. By eliminating the iron core of the stator, the coreless AFPM machine has the following advantages [6][7][8]: (1) The quality and cost of the machine are reduced; (2) The loss of the stator core and the cogging torque of the machine are eliminated; (3) The inductance of windings is small, and the influence of the stator current on the air gap flux density is almost negligible; (4) The ability of overload is greatly improved; (5) The arrangement of coils is more flexible and not constrained by slots and teeth of the stator.…”

Computationally Efficient Method of Co-Energy Calculation for Transverse Flux Machine Based on Poisson Equation in 2D

“…This situation causes that the task of numerical aided design of TFM type machines is, in terms of dynamic properties, an issue of very high computational complexity, especially when FEM 3D is applied to determine magnetic field distribution. The references include papers that present different approaches to decreasing computational complexity of the numerical aided design process of the machines with permanent magnets [15,16]. in references [17][18][19][20][21].…”