Direct Drive Train Consultancy

Belt Generators offers the following design services

for 2nd generation generators with concentrated coils and single slot mounting to obtain

a lean design with simplicity and cost reduction compared to a traditional design with focus on high efficiency >98%:

-   Magnetic design with recognized software FEM packages a.o. QuickField and an application code

  -Coupled FEM analyses between AC Magnetics and thermal heat flow identifying winding hot spot temperatures

 - Analyses including forced air cooling and/or liquid cooling

  -Benchmark between various parameters using an efficient application code

  -References to mechanical design, converter technique and insulation materials

  -Redundancy between more converter units avoiding heating up of the permanent magnets

  -Segmented modular rotor and stator for VPI and transportation

  -All over efficiency management for the wind turbine for minimizing energy cost

  -Logistics

Examples of design:

           - 25 MW design of a motor/generator at rated torque 32 MNm outer diameter 15 m 

           - 10 MW generator design at rated torque 10 MNm outer diameter 9 m.

- 5.0 MW generator at 11 rpm, rated torque 4,713 kNm, weight of active materials 21.6 tonnes, total weight 60 tonnes,

   outer diameter 5.9 m, cost in volume production below 660,000 EUR

- 30 kW generator at 2xxx rpm. 

- 25 kW generator at 65 rpm, rated torque 4,571 Nm, weight of active materials 320 kg, total weight 622 kg, outer

   diameter 800 mm, cost in volume production 5,100 EUR

At this stage improved air cooling and a novel type of coil  are used. The weight of active materials includes stator lamination and winding and permanent magnets.

Design methods used in the development:

FEM analyses of the magnetic circuit and use of a fast application software resulting in a short detailed design phase. Within short time benchmark is carried out for various parameters. Traditionally these analyses took weeks but now it takes days.

The deliverables are main data of performance, drawings of active magnetic parts and assistance to mechanical integration.

The used basic design is state of the art and proved in practise by many companies.

The optional innovative design elements are:

• Cooling with air or liquid media
• New but well-known coil design, simple and cost effective
• New lamination type
• Single slot concentrated coils with low cogging and ripple torque
• Segmented steel frame or nacelle integrated construction
• Permanent magnet hybrid design

The experience in active materials results in:

• Improved flux density in lamination
• Saving of rare earth permanent magnet weight
• Rationalized coil  winding in manufacturing and mounting
• Improved cooling
• Higher mechanical integration in the nacelle

Future design is dedicated new inexpensive materials for lamination, windings and permanent magnets. The efficiency will be designed for high values up to 98% for securing simple cooling and in particular low cost of energy (COE).