Small Wind Turbine

Innovative duplex concentric topology

The new topology saves up to 20-25% of the PCB stator winding losses. It increases the overall efficiency of the electric machine by 3-4% and can save up to 30GWh per year.

Introduction

Apart from low power-to-size/weight ratios and high material consumption, they have substantial electromagnetic losses. The absolute majority of motors in the range of up to 5kW operate at an average efficiency of 65-70% or less.

There are about 3 billion motors below 5kW rated power already installed worldwide. And they consume a massive amount of 1200GWh energy, of which 350GWh is wasted!

Moreover, the copper wire winding remains the electrical machine's weakest and most unreliable part.

The design and construction of traditional iron-core electric machines have remained unchanged for over a century

It is a relatively new type of electric machine offering numerous advantages – it has much higher electromagnetic efficiency and is more compact and lighter.

Known solutions

AF PMSM -
air-core axial flux permanent magnet synchronous machine

The pancake design of the AF PMSM makes it possible to replace the classic copper wire winding with a multilayer printed circuit board (PCB).

A stator with non-overlapping three-phase winding is located between two rotating metal disks with magnets. Several identical PCB layers are connected in parallel to achieve a higher current value in the winding.

Please hover over the images

A stator with non-overlapping three-phase winding is located between two rotating metal disks with magnets. Several identical PCB layers are connected in parallel to achieve a higher current value in the winding.

The PCB stator winding provides additional benefits:

much higher current density and reliability

thinner and lighter stator

easy fabrication with consistent quality

The Elfuturis topology is designed for an overlapping winding type. It requires two separate PCB layers for each phase, respectively, therefore, a three-phase PCB winding consists of a minimum of six layers.

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The coils are connected in a counter-series manner, where the beginning of
one coil is connected to that of the next.

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The active parts of the coil's turns cover most of the magnet pole area and are directed radially.

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The size and the length of passive parts are minimized. The result is a unique advantage providing the most efficient energy transfer, minimum losses, and optimized dimensions.

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New PCB winding topology

Elfuturis has developed, patented, and exclusively owns the innovative multilayer PCB stator winding topology for axial flux electric machines.

The technology invented by Elfuturis is genuinely disruptive for the global electric machine industry

The new duplex concentric PCB winding topology provides the balanced combination of such key parameters as the total active track length, passive-to-active part length ratio, magnet area coverage and others, resulting in the best-in-class figure of merit ever.

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Please click on the numbers

The name

is due to the doubling of the number of spiral coils in the phase winding compared to the classic concentric PCB winding topology.

“duplex concentric PCB winding topology”

The top (red) and bottom (blue) layers of the new duplex winding topology (see above) and classic concentric one (see below). The arrows show the direction of the EMF vectors determined by the interaction of tracks with magnets (shown in grey).

The new topology provides the same electromagnetic parameters as the classical one, but is more compact and its passive part is almost twice as short.

The top (red) and bottom (blue) layers of the new duplex winding topology (left) and classic concentric one (right). The arrows show the direction of the EMF vectors determined by the interaction of tracks with magnets (shown in grey).

The new topology provides the same electromagnetic parameters as the classical one, but is more compact and its passive part is almost twice as short.

To connect the next PCB in series, you only need to turn it the other way (back to front) in relation to the previous one. Then connect the PCB terminals with jumpers in the regular way as shown here.

The AF PMSM’s modular stacking design and enhanced terminal system for both series and parallel PCB interconnection will extend the operating power range up to 5-10kW with optimum winding parameters

To connect the next PCB in series, you only need to turn it the other way (back to front) in relation to the previous one. Then connect the PCB terminals with jumpers in the regular way as shown here.

Advantages of Elfuturis' topology

The innovation's most evident benefit is an almost twofold reduction in the length of the winding's passive parts and power losses while the highest possible efficiency is maintained in the winding's active zone.

As for the entire phase winding, the new topology reduces its resistance and power losses accordingly by about 20-25%

This topology also downsize the winding and further improves the already exceptional parameters of the axial flux machine, such as high electromagnetic efficiency, compact size, low weight, and the highest reliability.

New duplex (up) and classic (down) concentric PCB winding topologies for the top phase B layer of 16-poles AF PMSM. The classical topology has almost twice as long passive parts and a much larger size. Patented and more patents pending.

New duplex (left) and classic (right) concentric PCB winding topologies for the top phase B layer of 16-poles AF PMSM. The classical topology has almost twice as long passive parts and a much larger size. Patented and more patents pending.

40%

share of losses in the stator winding in the total power losses of the electric machine

20-25%

saving of wasted energy in PCB stator due to the new topology

3-4%

increase in the electric motor or alternator's efficiency

30GWh

energy saved per year in the global segment of machines up to 5 kW

Applications

The application field of the new topology is limitless

The use of axial flux machines as an alternative to the classic iron-core type is growing exponentially. Here are just some examples of its potential use:

EV motors (bikes, drones, copters)

Home appliances, toys

Industrial motor drives, robots

Micro-drives for medicine, precise tools

Generators, wind turbines

IT (HDD, fans)

Control and automation devices

Aircrafts, space

EV motors (bikes, drones, copters)

Home appliances, toys

Industrial motor drives, robots

Micro-drives for medicine, precise tools