KD 645 added

Report KD 645 is added. The title of this report is: “Ideas about a 10-pole, 3-phase permanent magnet generator with a stator without iron in the coils, using 20 neodymium magnets size 50 * 20 * 10 mm and a housing of an asynchronous motor with frame size 80”. The main difference in between this 10-pole PM-generator and the 8-pole PM-generator as described in report KD 644 is that the 10-pole PM-generator has a simpler 1-layer winding.

KD 480 replaced by KD 644

Report KD 480 is replaced by report KD 644. Report KD 644 has as title: “Ideas about an 8-pole, 3-phase permanent magnet generator with a stator without iron in the coils, using eight neodymium magnets size 80 * 20 * 10 mm and a housing of an asynchronous motor with frame size 71”. Although the magnet and copper costs of this generator are rather high, advantages are that the generator is completely closed, that it will have almost no sticking torque and that it will have a high efficiency because there are no iron losses and because there is enough space to use thick wires.

Notitie Harmonisch intoneren

Onder het menu “No wind energy” werd de notitie “Harmonisch intoneren” toegevoegd. Deze notitie is een samenvatting van mijn bijdrage aan een discussie over dit onderwerp op het Strijkersforum naar aanleiding van mijn notitie “Een notenschrift zonder mollen en kruizen”.

KD 632 reviewed

A 26-pole PM-generator made from an asynchronous motor frame size 80 is described in report KD 632. Several new chapters were added to KD 632 in which the design calculations are given for the 2-bladed VIRYA-2.2 rotor with cambered galvanised steel blades. This simple rotor can be connected to the 26-pole generator. The VIRYA-2.2 uses the same head and tower as the VIRYA-2.2S.

Licence fees for bigger VIRYA windturbines halved; VIRYA-3.18 cancelled

I am ritired now for some years and I no longer need substantial income out of my activities for Kragten Design. Therefore I have halved the licence fees for the bigger VIRYA wind turbines for which a licence is required. The new licence fees can be found on the folder “Extended specification VIRYA windmills” which you find at the menu “VIRYA-folders”.

The VIRYA-3.18 with a Chinese axial flux generator and a 2-bladed steel rotor with a design tip speed ratio of 7 is cancelled. This is done because experiences with the 2-bladed steel rotor of the VIRYA-1.65 have shown that too much noise is produced for steel rotors with 7.14 % cambered blades if the design tip speed ratio is that high.

KD 532 reviewed

Report KD 532 gives the rotor calculations of a 3.1 m diameter, 2-bladed rotor made out of Roofmate and glass fibre. A new chapter 6 has been added in which it is checked if this rotor matches with the Chinese axial flux generator of Hefei Top Grand type TGET260-0.5KW-350R. As generator characteristics for a 24 V battery load are not available, these characteristics were estimated from the given specification of the manufacturer.

KD 595 reviewed

Report KD 595 with the measurements of a Chinese axial flux generator has slightly been reviewed. A reference 4 to the VIRYA-1.5 rotor has been added.

KD 634 added, KD 490 reviewed

Report KD 634 has been added to the list of free public KD-reports. The title of this report is: Calculations executed for the 3-bladed rotor of the VIRYA-3.4 windmill (lambda design = 4.5, galvanised steel blades) driving a centrifugal pump through a Polycord transmission with i = 2.5 and a vertical shaft in the tower centre. Report KD 623 has been added to the references of report KD 490: Water pumping with a windmill.

Polycord data sheet added to KD 320

The original pdf file of report KD 320 about the Polycord transmission of the VIRYA-2.8B4 was larger than 2 Mb and therefore it could not be added to my website completely. The data sheet of the Polycord transmission in between the rotor shaft and the vertical shaft was therefore removed. This data sheet has be scanned again but now on a lower resolution of 100 dpi and the report is now small enough to present it completely.