Conny Högmark

Heat transfer analysis of a traction machine with directly cooled laminated windings

A directly enhanced cooled winding in an electrical traction machine has the potential to extend the operation range, which is in particular attractive for a traction application when operating near peak power for extended periods of time. This paper presents the heat transfer analysis of a modular machine segment with a laminated winding. The laminated winding has a great potential when it comes to production of the winding and the thermal management of the excessive power losses in the winding. The prototype is built and assessed based on experimental measurements and finite element analysis. The results indicate some practical challenges of integrating the combined heat exchanger and winding and controlling the coolant flow through the machine construction. The prototype machine shows a limited enhanced cooling capability mostly due to flow leakage while the results from the simulation models indicate the great potential of direct cooled windings.

Sub-Optimization of a Claw-Pole Structure According to Material Properties of Soft Magnetic Materials

The focus of this paper is on the development of a single phase PM machine with wave-windings where the design variables are the winding layout and design of a soft magnetic powder core for a stator. A number of BH curves are synthesized in order to characterize some of the existing powder cores and to study the influence of magnetic permeability on starting torque and mean driving torque. The goal of the wave-winding design is to increase the material utilization factor and minimize the resistive power losses in the winding of a radial-to-transversal flux machine with an iron powder core. The outcomes of this paper is a 3D FE magnetic analysis of a number of suggested stator layouts supported with a rapid prototype with a dummy coil.

Evaluation of a semi claw-pole machine with SM 2 C core

New development in material and production technology influences the design of electrical machines. This paper presents a theoretical calculation and experimental verification of a single-phase semi claw-pole machine, which core is made of Soft Magnetic Mouldable Composite - SM2C. In comparison with a conventional claw-pole configuration the semi-claw pole machine has a higher torque capability. This is due to a slightly increased winding arrangement.

Electrical machines with laminated winding for hybrid vehicle applications

This paper focuses on the experimental evaluation and design of a magnetic core of a modular segment for a synchronous machine with a laminated wave-winding. The advantageous features of laminated windings, which are the simple production and the high winding fill factor with a good net shape, are optimized towards high torque capability. The focus in this study lies on the design of soft magnetic core rather than the thermal design of an assembled system. The manufacturability and the electromagnetic energy conversion are compared and evaluated in a number of stator segments with both powder and laminated core. The evaluations of the energy conversion capability and manufacturability show the potential with a laminated winding/yoke and also with laminated winding/core segments configurations. The comparison shows that the design considerations in the modelling of the energy conversion match well with the measured results. The experimental results from the small alternator are used to propose a design strategy for a hybrid traction machine with the same topology.

Prototype based study of different winding configurations with SM 2 C core

This paper summarises the outcome of an experimental study, which is related to a winding arrangement in a stator core that is made of Soft Magnetic Mouldable Composite - SM2C. The comparison is made between a distributed concentrated winding and a modular wave-winding, where the modular wave-coils are distributed either axially or circumferentially. Manufacturability and high winding fill factor are vital for a low permeability stator core in order to gain a good machine performance and a low cost in combination with moulding technique. A number of stators are built and verified in order to learn the theoretical and practical issues related to wave-windings.

Design and prototyping a torus machine with a rotocast core.

A torus machine is considered to be an advantageous machine configuration that is impossible to produce using traditional laminated core technology. This paper presents a torus machine with the stator winding moulded into a composite core, using the RotoCast technology. The goal of the design and the prototyping is to study the advantages when dealing with a soft magnetic mouldable composite material (SM2C) while looking for alternative and inexpensive production methods.

Alternative production process for electric machine windings

The development of production methods, research on material engineering and analysis tools for energy conversion processes establish a powerful design environment for any unconventional electromagnetic or electromechanical device. The design for manufacturability becomes the one of the main goals of the design apart from cost and performance improvement. The main focus of this paper lies on the development of production methods, the design of the product, a wave-winding, and the component assessment in an electrical machine. The production of non-complex coil with maximized performance capability of the molded core machine is the target for the design of the winding and also the design for the winding machine. Four different types of wave-windings are described and evaluated. One of them, wind and bend with conventional wire, has main focus in this work, and a prototype of the winding machine is built to produce the single-layer whole-lap wave-winding. The production method, manufacturing process and the processed component features are analyzed in this paper.

Modular three-phase machines with laminated winding for hybrid vehicle applications

A design model development for electrical machines with laminated windings is presented. The focus is to provide manufacturable solutions for commercial vehicle traction applications. The machine is designed with axially distributed single-layer wave-winding segments with a core that builds a modular three-phase machine. The phase segment, whose central part is a wave-winding made as a laminated winding, form a semi-claw pole structure. A conventional permanent magnet synchronous machine is used as a reference. The result indicates that comparable torque and power can be reached with the suggested alternative design.

An integrated design of SM 2 C core motor for vehicular applications

This paper focuses on the design and the evaluation of a three-phase permanent magnet synchronous machine (PMSM) with a stator core made of Soft Magnetic Mouldable Composite - SM2C. A radial flux PM machine with modular winding is designed for a high-speed low-voltage automotive application. Manufacturability and a high winding fill factor are vital for a low permeability stator core in order to gain a good performance and a low cost in combination with moulding technique. Two stators are built and verified with good results.